This page is for an external rescue mission coming to the aid of astronauts trapped in a Distressed Vehicle. For emergency gear carried on a distressed vehicle so the crew can do self-help, go here.

In the early days of space flight, the various space agencies could barely get an astronaut into orbit. The idea of sending a rescue mission to give aid and succor for a stricken astronaut was probably not in technologically feasible, and was certainly not in the budget.

However the Skylab mission raised some troubling scenarios. What probably lit a fire under NASA's behind was the release of the book and movie 'Marooned.' This depicted a nice space rescue. NASA realized that if an accident happened in the real-life Skylab mission and they could not rescue the crew, they would have a public relations nightmare on their hands. Joe Smoe on the street believes what they see, so even though the movie was nowhere near realistic it was real to the public. The popular conclusion would be that the only reason NASA couldn't rescue the Skylab crew from a hypothetical disaster would be NASA incompetence.

As it turns out NASA did have a spare Apollo CSM and launch vehicle. So they jury rigged it to be capable of holding five astronauts instead of just three. And the first space rescue vehicle was born.

In a rocketpunk future, most of this equipment would be used by the Orbit Guard and other national or private organizations who perform Search and Rescue.

With respect to private search-and-rescue organizations Rob Garitta notes, "Nearly all SAR operators double as salvage operations because sometimes they don't make it in time."


      In the late 20th century, the first unmanned probes were sent to Mars. Most of them failed; of the thirty-nine missions launched by America and Russia between 1960 and 1999, nine exploded during lift-off, seven lost contact with home, seven more either went into useless orbits or missed the planet entirely, and four crashed while attempting to land. No other program had the same failure rate, nor as many mishaps that couldn’t be easily explained.

     This led someone at NASA to playfully suggest that a creature lurked between Earth and Mars, a gremlin ready to sabotage or destroy any spacecraft that dared to enter its realm. The Great Galactic Ghoul became a standing joke among engineers and ground controllers, but as the missions continued to fail, the laughter stopped. It soon came to be considered bad luck to mention the Ghoul. Even if these otherwise rational men didn’t necessarily believe in space monsters, neither were they willing to say anything that might jinx the mission.

     Despite the setbacks, Mars was explored and people eventually went there, and not long after that they began to travel further out into the solar system. By then, they’d learned how to build spacecraft that were reasonably safe and reliable; they had to, because the consequences of catastrophic failure were unthinkably high. There were accidents, of course, and occasionally a life was lost, but those instances were rare; when they occurred, more often than not human error was the primary cause. In any case, investigations would be announced, studies would be made, data collected, reports written, findings announced. Changes would then be instituted, and if the process worked the way it was supposed to, that particular accident would never happen again. Or at least not quite the same way.

     In time, the Great Galactic Ghoul was forgotten. But he didn’t disappear. He simply went into hiding for awhile, waiting for the day to come when he could return from the shadows and wreak havoc upon any vessel he happened to encounter in the darkness between worlds.

     Until August 16, 2062, there had never been a deep-space rescue mission. There were countless instances, of course, between Earth and the Moon in which one spacecraft made an emergency rendezvous with another. The distance involved there was less than a quarter of a million miles, though, and since there were over a dozen stations in cislunar space, help was seldom more than a few hours away. Beyond the Moon, the situation was different; spacecraft crews were expected to deal with onboard accidents themselves, without relying on outside assistance. And for good reason; Earth and Mars were separated by an average of 49 million miles, and even in the most densely populated zone of the asteroid belt, tens of thousands of miles could lay between one inhabited rock and another.

     Nonetheless, it wasn’t long before spacers realized that they needed to plan for coming to one another’s aid. No one could anticipate every sort of emergency, but there were times when it would have been helpful to know, no matter how bad things might be, that help was on the way. Indeed, one of the first things the Pax Astra did after it was formed in 2049 was to ratify the space rescue clause of the old 1967 U.N. Space Treaty even though the Pax rejected most of the treaty’s other provisions. As much as the newly independent space colonies wanted to break away from Earth, this part of the treaty, which mandated that all space vessels had to respond to distress signals, was worth keeping.

     It’s a good thing that the Pax settled this particular issue, for only six years later the belt colonies broke away to form their own alliance, the Transient Body Shipping Association. Since the TBSA was willing to do business directly with Earth-based companies and governments, economic rivalry with the Pax Astra was assured. So it was just as well that Pax and TBSA ships formally agreed to come to each other’s aid in times of emergency; by 2065, each side would be committing piracy against the other, with worse yet to come…

From THE GREAT GALACTIC GHOUL by Allen Steele (2010)

Emergency Situations


  • Fire
    • Electrical
    • Chemical
    • Other
  • Explosion
    • Liquid
    • Gas
    • Ordnance (carried weapons or ammunition)
  • Explosion / Implosion
  • Decompression / Overpressure
  • Temperature and Humidity Out Of Limits
  • Power Loss
  • Collisions (Internal / External Objects)
  • Contamination (Toxic / Non-Toxic)
  • Atmospheric Contamination
  • Injury And Poisoning
    • Chemical Injury
    • Radiation Injury
    • Physical Injury
  • Illness
    • Infective and Parasitic
    • Other
  • Mental, Psychoneurotic, Personality Disorders
  • Mechanical / Structural Failures (Non-collision-oriented)
  • Radiation (Internal / External)
  • Personnel Errors
  • Basic Subsytem Malfunctions
  • Inability To Return From EVA
  • Food/Water Contamination/Loss
  • Buildup Of Dangerous Bacteria
  • Lack Of Resupply / Rotation
  • Hostile Action (terrorist, saboteurs, enemy military action, etc.)

Emergency Situations

  • Ill or Injured Crew (physical, chemical, disease, mental)
  • Metabolic Deprivation
    • Anoxia
    • Dehydration
    • Starvation
  • Stranded or Entrapped Crew
    • during EVA
    • in vehicle
  • Inability to Communicate
  • Out-of-Control Spacecraft
    • tumbling in safe orbit
    • in decaying orbit
    • on unsafe trajectory
  • Debris in Vicinity
  • Radiation in Vicinity
  • Non-Habitable Spacecraft Environment
    • lack of environmental control (pressure, temperature, humidity extremes)
    • contamination (experiments, animals, insects, bacterial)
    • Radiation (internal source)
  • Abandonment (crew in EVA after bail-out in lifeboat)
  • Inability to Reenter Earth's Atmosphere

      The harassed Controller had lived in an aura of “Restricteds,” “Classifieds” and “Top Secrets” for so long it had become a mental conditioning and automatically hedged over information that had been public property for years via the popular technical mags; but in time they pried from him an admittance that the Station Service Lift rocket A. J. “Able Jake” Four had indeed failed to rendezvous with Space Station One, due at 9:16 Greenwich that morning.
     There may have been a collision with a meteor he conceded, but, it was thought, highly unlikely. And now, the urgent business of the search called, the Controller escaped, perspiring gently.
     Able Jake was sighted a few minutes later but it was another three hours before a service ship could be readied and got away without load to allow it as much operating margin as possible. Getting a man aboard was yet another matter. At this stage of space travel no maneuver of this nature had ever been accomplished outside of theory. Fuel-thrust-mass ratios were still a thing of pretty close reckoning, and the service lift ships were simply not built for it.
     The ship was in an elliptical orbit and a full degree off its normal course. A large part of the control room was demolished and there was a lengthy split in the hull. There was no sign of the pilot and some of the cargo was missing also. The investigating crew assumed the obvious and gave it as their opinion that the pilot had been literally disintegrated by the intense heat of the collision.
     The larger part of the world’s population made it a point to listen in on the first space burial service in history over the absent remains of Johnny Melland.

     Such a small thing to cause such a fury. A mere twenty Earth pounds of an indifferent grade of rock and a little iron, an irregular, ungraceful lump, spawned somewhere a billion years before as a star died. But it still had most of the awesome velocity and inertia of its birth.
     Able Jake, with the controlling influence of the jets cut, had yawed slightly and was now traveling crabwise. The meteor on its own course, a trifle oblique to that of the ship, struck almost directly the slender spring steel spine, the frightful energy of the impact transmuted on the instant into a heat that vaporized several feet of the nose and spine before the dying shock caused an anguished flexing of the ship’s backbone; thrust violently outward along the radial members and so against the ribs and hull sheathing on that side. Able Jake’s hull split open like a pea pod for fully half its length and several items of its cargo burst from their lashings, erupted from the wound.
     Johnny was not inboard at the time, but floating, spacesuited alongside, freeing a fouled lead to the radar bowl, swearing occasionally but without any real passion at the stupidity of the unknown maintenance man who failed to secure it properly. For some odd reason he had never quite lost the thrill of his first trip “outside,” and, donning pressure suit with the speed of long practice, sneaked as many “inspections” as possible, with or without due cause.
     The second’s fury that reduced the third stage of a $5,000,000 rocket to junk was evident to him only as a brilliant blue-white flash, a hammer-like shock through the antennae support that left his wrist and forearm numb. Then a violent wrench as a long cylinder, expelled from the split hull, caught the loop of his life line and dragged him in till he clashed hard against it, the suddenly increased tension or a sharp edge parting the line close to the anchored end. He clawed blindly for a hold, found something he could not at that moment identify and hung on.
     For a short time his vision seemed dulled and that part of his mind, trained to the quick analysis of sudden situations groped but feebly through a haze of shock to understand what had happened. Orienting himself he found he was gripping a brace of the open-mounted motor on one of the Waste Disposal Cylinders. About him he could see other odd items of the cargo, some clustering fairly closely, others just perceptibly drifting farther away. To one side, or “downwards” the Earth rolling vastly, pole over pole, and with her own natural rotation giving an odd illusion of slipping sideways from under him.
     Only a sudden sun glint on the stubby swept-back wings showed him where Able Jake was. Far away—too far, spinning slowly end over end. His sideways expulsion from the ship then had been enough to give him and his companion debris a divergent course.
     Spacemen accept without question the fact of a ship or a station always at hand with a safety man on watch at all times over those outside and a “bug” within signaling distance constantly. They do not conceive of any other state of affairs.
     Now Johnny had to face the fact that he was in such a position—entirely and utterly alone, except for the useless flotsam that came with him. He might have flung himself into a mad chase after the ship on his suit jets except that the thought of leaving his little island, cold comfort though it was, to plunge into those totally empty depths was suddenly horrible.
     The tide of panic rose within him. He knew the sickening bodily revolt of blind unreasoning terror—the terror of the lost, the terror of certain untimely death, but mostly of death so dreadfully alone.
     He might have gone insane. In the face of the insoluble problem his mind might have retreated into a shadow world of its own, perhaps to prattle happily the last few hours away. But there was something else there. The pre-flight school psychiatrist had recognized it, Johnny himself probably wouldn’t have and it wasn’t their policy to tell him. It saved him. The labored heart pounding and the long shuddering gasps slowed in time and with the easing of his physical distress he found enough heart to muster a wry little smile at the thought that of the castaways of history he at least stood fair to be named the most unique.

     And after a while, shaking himself mentally, a little ashamed of his temporary fall from grace, he followed the example of the more intelligent of his predecessors and settled down to itemize his assets, analyze his position and conjecture the chances of survival.
     Item: He was encased in a Denby Bros. spacesuit, Mark III, open space usage, meant for no gravity use. Therefore it had no legs as such, the lower half being a rigid cylinder allowing considerable movement within and having a swivel mounted rocket motor at its base controlled by toe pedals inside.
     The upper half, semiflexible with jointed arms ending in gloves from which by contorting the shoulders the hands could be withdrawn into the sleeves when not in use.
     A metal and tinted plastic helmet with earphones, mike and chin switch. An oxy air-conditioning and reprocessing unit with its spare pure oxygen tank; on this he could possibly depend for twelve hours given no undue exertion and with the most rigid economy all the time.
     The power pack for suit operation and radio had a safety margin of one hour over the maximum air supply, if the radio wasn’t used. At this time Johnny couldn’t see much use for it.
     Item: One Waste Disposal Cylinder, expendable, complete with motor and full fuel tanks, packed, according to his loading manifest with sundry supplies to avoid dead stowage space. Seldom used, since most station waste was ferried down in the otherwise empty service ships, they occasionally handled certain laboratory refuse it was considered best to destroy in space. The cylinders were decelerated and allowed to fall into atmosphere where the friction of the unchecked plunge burned up what the magnesium charge inside had not already. The rest of the shipwrecked material had by now drifted beyond easy reach and Johnny did not feel like wasting fuel rounding it up.
     Position? A matter of memory and some guesswork by now. Some ten minutes out of powered flight at the time of collision, coasting up to station orbit where a quick boost from the jets would have made up his lost velocity to orbit standard. But there would be no boost now. So he’d just fall off around the other side, falling around and into Mother Earth, to skim atmosphere and climb on past and up to touch orbit altitude—and down again. A nice elliptical orbit, apogee a thousand odd miles, perigee, sixty-seventy—perhaps. How much speed had he left? How long would it be before he brushed the fringe of atmosphere once too often and too deep? Just another meteor.
     And survival. A comparatively simple problem since the mechanics of it were restricted by a simple formula in which his role would seem to be a passive one. To survive he must be rescued by his own kind in twelve hours or less. To be rescued he must be seen or heard. Since his radio was a simple short-range intercom it followed that he must be seen first and heard later. Being seen meant making a sufficiently distinguishable blip on somebody’s radar screen to arouse comment over a blip where, according to schedule no orbiting blip should be.

     Johnny was painfully aware that the human body is very small in space. The cylinder would be a help but he doubted it would be enough. Then he thought of the material inside the cylinder. He pried back the lugs holding the cover in place with the screwdriver from his belt kit. He started pulling out packages, bags, boxes, thrusting them behind him, above him, downwards; cereals, ready mixed pastries, bundles of disposable paper overalls—toilet paper! He worked furiously, now stuck halfway down the cylinder, kicking the bundles behind him. He emerged finally in a flurry of articles clutching a large plastic bag that had filled the entire lower end of the tank.
     About him drifted a sizable cloud of station supplies, stirring sluggishly after his emergence. He pushed them a bit more, distributing them as much as possible without losing them altogether.
     Johnny tore open the big bag and was instantly enveloped in clinging folds of ribbon released from the pressure of its packing. He knew what it was now, the big string of ribbon chutes for the Venus Expedition, intended for dropping a remote controlled mobile observer to the as yet unseen and unknown surface. Johnny had ferried parts of the crab-like mechanical monster on the last run, and illogically found himself worrying momentarily over the set-back to the Probe his mischance would cause.
     But in the next minute he was making fast the lower end of the string to the WD cylinder, then, finding the top chute he toed his pedals and jetted himself out, trailing the string out to its full extent.
     Now the period of action was over and he had done all he could, Johnny found himself dreading the time of waiting to follow. He would have time for thinking, and thinking wasn’t profitable under the circumstances unless it were something definitely constructive and applicable to his present and future well-being. Waiting was always bad.
     Surely they would find him soon. Surely they would press the search farther even when they found Able Jake as they couldn’t fail to in time.
     A tightness started in his throat. Johnny quickly drowned the thought in a flood of inconsequential nonsense, a trick he had learned as a green pilot. He might sleep though, if sleep were a possible thing in this cold emptiness. No one, to his recollection, had ever done so outside a ship or station—the space psychology types would be interested doubtless.

     Johnny tied his life line to the WD cylinder and then jetted clear of his artificial cloud, positioning himself so that it formed a partial screen between himself and the sun. He turned his oxygen down to the bare minimum and the thermostat as low as he dared. He commenced a relaxation exercise and was pleased when it worked after a fashion—a mental note for Beaufort at the station. A drowsiness crept over him, dulling a little the thin edge of fear that probed his consciousness.
     Face down towards the earth he hung. The slow noise of his breathing only intensified the complete silence outside. The well padded suit encompassed him so gently there was no sense of pressure on his body to make up for the weightlessness. Johnny felt as though he were bodiless, a naked brain with eyes only hanging in nothingness.
     Beneath, Earth rolled over with slow majesty, once every two hours. His altered course was evident now, passing almost directly over the geographic poles proper instead of paralleling the twilight zone where night and day met. Sometimes he caught the faint glow of a big city on the night side but the sight only stirred the worm of anxiety and he closed his eyes.
     Johnny was beginning to feel very comfortable. He supposed sleepily that this was the way you were assumed to feel while freezing to death in a snowbank, or so he’d heard. Air and heat too low perhaps. He should really turn it up a notch.
     On the other hand it was perhaps a solution to the problem of dying—a gentle sleep while the stomach was still full enough from the last meal to be reasonably comfortable and the throat yet unparched. Would it be the act of an unbalanced mind or one of the most supreme sanity?
     He dozed and dreamed a bit in fragments and snatches but it was not a good sleep—there was no peace in it. At one time he seemed to be standing outside the old fretworked boarding house he lived in—looking in at the window of the “sitting room” where the ancient, wispy landlady sat among her antimacassared chairs and the ridiculous tiny seashell ashtrays that overflowed after two butts. He wanted desperately to get in and sprawl in the huge bat-winged chair by the fire and stroke the enormous old gray cat that would leap up and trample and paw his stomach before settling down to grumble to itself asthmatically for hours.
     It was cold and dark out here and he wanted to get in to the friendliness and the warmth and the peaceful, familiar security, but he didn’t dare go around to the door because he knew if he did the vision would vanish and he’d never find it again.
     He scratched and beat at the window but his fingers made no sound, he tried to shout but his cries were only strangled whispers and the old lady sat and rocked and talked to the big gray cat and never turned her head.
     The fire seemed to be flaring up suddenly, it was filling the whole room—a monstrous furnace; it shouldn’t do that he knew, but the old lady didn’t seem to mind sitting there rocking amid the flames—and it was so nice and warm. The fire kept growing and swelling though—soon it burst through the window and engulfed him. Too hot. Too hot.

     Johnny swam hazily back to consciousness with an aching head and thick mouth. He saw that he had drifted clear of his protective screen somehow and the sun beat full on him. With clumsy, fumbling hands that seemed to belong to somebody else he managed the air valve; the increased oxygen reviving him enough to find the pedals and jet erratically about till he gained the shadow once more.
     Now he was entering upon the worst phase of the living nightmare. Awake, the doubts and fears of his position tormented him; wearied, he feared to sleep, yet continually he found himself nodding only to jerk awake with that suddenness that is like a physical blow. Each one of these awakenings took away a little more of his self-control till he was reduced to near hysteria, muttering abstractly, sometimes whimpering like a lost child; now seized with a feverish concern for his air supply. He would at one instant cut it down to a dangerous minimum, then, remembering the near disaster of his first attempt at economy, frantically turn it up till he was in danger of an oxygen jag. In a moment he would forget and start all over again.
     In addition, he was now realizing bitterly what he had subconsciously denied to himself for so long, that they had found Able Jake and drawn the obvious conclusion. That he had been obliterated or blown out through the hull by the collision without warning or preparation. That he was undoubtedly dead if not vaporized altogether and, as they must, considering the expense of a probably fruitless search, abandon him.
     There came the moment when Johnny accepted this in full. This was directly after the time when, sliding down the long hill to the perigee of his orbit, he turned on his radio and cried for help. It was a bare hundred miles or less to that wonderful world below, but there was the Heaviside layer, and the weak signals beat but feebly against it. All that seeped through by some instant’s freak of transmission was a fragment of incoherent babble to reach the uncomprehending ear of an Arkansas ham and give that gentleman uneasy sleep for some time to come.
     He kept calling mechanically even after perigee was long past, praying for an answer from the powerful transmitters below or from a searching ship. But when there was no slightest whisper in his phones or answering flare among the stars, Johnny came to the end of faith. Even of awareness, for his own ears did not register the transition of his calls to an insane howling of intermixed pleas, threats, condemnation—a sewer flood of foul vilification against those who had betrayed him.
     Bright and beautiful, Earth rolled blandly beneath him, the sun was a remote impersonal thing and the stars mocked silently. After a while the radio carried only the agonized sounds of a man who had forgotten how to cry and must learn again. There were times after this when he observed incuriously a parade of mind pictures, part memory, part pure hallucination and containing nothing of reason; other times when he thought not at all. The sun appeared to dwindle, retreating and fading far away into a remote place where there were no stars at all. It became a feeble candle, guttered unsteadily a moment and suddenly winked out. Abruptly Johnny was asleep.

     He opened his eyes and surveyed the scene with an oddly calm and dispassionate curiosity, not that he expected to find his status changed in any way but because he had awakened with a queer sense of unreality about the whole business. He knew vaguely that he’d had a bad time in the last few hours but could remember little of the details save that it was like one of those fragmentary nightmares in the instant between sleeping and waking when it is difficult to divide the fact from the dream. Now he must reassure himself that this facet of it was real and when he had done so, realized with a faint shock that he was no longer afraid.
     Fear, it seemed, had by its incessant pressure dulled its own edge. The acceptance of inevitable death was still there, but now it seemed to have little more significance than the closing of a book at the last page.
     It is possible that Johnny was not wholly sane at this point, but there is no one to witness this and Johnny, not given to introspection at any time, felt no spur to self-analysis, beyond a brief mental registration of the fact.
     So he made his visual survey, saw that it was real, nothing had changed; noted with mild surprise that he’d somehow remained in the shadow of his screen this time. He had lost track of time entirely but the suit’s air supply telltale was in the yellow indicating about two hours more or less to go on breathing. In quick succession he reviewed the events, accepted the probability of the abandoned search without a qualm and made his decision. There was no need to wait about any longer.
     A quick flip of the helmet lock, a moment’s unpleasantness perhaps, and out. As for the rest—a spaceman needs no sanctified ground, the incorruptible vault of space is as good a place as any and perhaps the more fitting for one of the first to travel its ways.
     Well then—quickly. Johnny raised his hands.
     But still—
     Man has his pride and his vanity. Johnny, though not necessarily prone to inflated valuation of himself still has just enough vanity left to resent the thought of this anonymous snuffing out in the dark. There should be, he thought, at least some outward evidence of his passing, something like—a flare of light perhaps, that would in effect say, if only to one solitary star gazer: “Here at this position, at this instant, Johnny Melland, Spaceman, had his time.”
     The whimsy persisted. Johnny, casting about mentally for some means to the end recalled the thermite bomb for the WD cylinder and was hauling himself in to it when he remembered the charges for this lot had gone up with Sally Uncle One two days before. But now he’d actually touched the metal cylinder and, as though the brief contact had completed some obscure mental circuit, the mad idea was conceived, flared up into an irrepressible brilliance and exploded in a harsh bark of laughter.
     One last push to his luck then, hardly worse than a gambler’s last chip except that the consequences of failure were somewhat more certain. Either way he’d have what he wanted—survival or, in the brief incandescence of friction’s heat, a declaration of his passing.
     A waste disposal cylinder will carry the equivalent of about three tons of refuse. Its motor is designed to decelerate that mass by 1,075 mph in order to allow it to assume a descending orbit.
     Less the greater part of the customary mass, it should be considerably more effective, and since he was already in what constituted a descent path, but for a few miles and a little extra velocity, there would not be the long fall afterwards to pick up what he’d lost.

     From there on his plan entered the realm of pure hypothesis; except for the broad detail the rest depended on luck and whatever freakish conditions might arise in his favor during the operation. These, too, would be beyond his control and any move to take advantage of them would have to be instinctive, providing he was in any shape to do so.
     The tendency to gnaw worriedly at a thousand disturbing possibilities drowned quickly in a rapidly rising sense of reckless abandon that possessed him. The prospect of positive action of any sort served to release any tension left in him and almost gayly he moved to set his plan in action.
     He jimmied the timer on the rocket motor so it would fire to the last drop. The string of ribbon chutes he reeled in hand over hand stuffing it into the cylinder, discovering in the process why the chute Section hands at Base wore that harried look. The mass of slithering, incompressible white-and-yellow ribbon and its shrouds resisted him like a live thing; in the end Johnny managed to bat and maul the obstreperous stuff down the length of the tank. Even so, it filled it to within a couple of inches of the opening.
     Now he cut off a length of his life line and attached one end to the spring-loaded trigger release on the motor control, leaving enough to trail the length of the cylinder and double back inside when he wanted it. He blessed the economically minded powers that insisted on manual firing control on these one-shot units instead of the complex radio triggers beloved of the technical brains.
     Making fast to the chutes was a major problem but eventually he managed a makeshift harness of the remainder of the safety line. He wound it awkwardly around himself with as many turns as possible, each returned again and again through, the ring at the end of the master shroud.
     By now he was casting anxious glances at the Earth below, aware that he must have passed apogee several minutes before and that not more than some twenty minutes were left before the low point of this swing would be near. He was grimly aware also that it must be this time or not at all. The air telltale was well through the yellow band and the next possible chance after this one was an hour’s time away, when conditions inside the suit would be getting pretty sticky.
     Jockeying the unwieldy cylinder into line of flight and making it stay there took a lot longer than Johnny counted on. With no other manual purchase than that afforded by his own lesser mass, the job proved almost impossible and he had to use his suit motor. This caused some concern over his meager fuel supply since his plan called for some flat-out jetting later on. In the frantic flurry of bending, twisting, over and under—controlling, the veneer of aplomb began to wear. Johnny was sweating freely by the time he had the cylinder stabilized as best he could judge and had gingerly worked himself into the open end as far as he could against the cushioning mass of ribbon chute. He took the trigger lanyard loosely in hand and craning his neck to see past the bulk of the cylinder he watched and waited.

     To the experienced lift pilot there are certain subtle changes in color values over the Earth’s surface as one approaches more closely the outer fringe of atmosphere. While braking approaches are auto-controlled, the pilot taking over only after his ship is in atmosphere, the conscientious man makes himself familiar with the “feel” of a visually timed approach—just in case—and Johnny was a good pilot.
     Watching Equatorial Africa sliding obliquely towards him Johnny suddenly gave thought to a possible landing spot for the first time. Not that he had any choice but a picture of a cold, wet immersion in any of several possible bodies of water was not encouraging. The suit would probably float but which end first was a matter for conjecture and out of it he would be as badly off for Johnny could not swim a stroke.
     Nor had he any clear idea how long it would take to slow down to a vertical drop. Able Jake made a full half swing of the globe to brake down but Able Jake was an ultra-streamlined object with many times the mass and weight of Johnny and his rig; furthermore the ships were controllable to a certain degree while Johnny was not. Beyond the certain knowledge that the effect of the chutes would be quite violent and probably short-lived, the rest was unpredictable.
     He tried to shake off gloomy speculation, uneasily aware that much of the carefree confidence of the last hour had deserted him. In a more normal state of mind again he became prey to tension once more, a pounding heart and dry mouth recalling mercilessly the essential frailties of his kind. So, with aching neck and burning eyes he strained for a clear view past the length of the cylinder and—
     There! The preliminary to the visual changes, a sudden sweep of distortion over the landscape as his angle of sight through the refracting particles became more shallow. Now was the time he had judged the throat vane gyros should begin their run-up.
     He worked the lanyard back carefully, fearful an awkward movement might upset the cylinder’s line-up, pulling the trigger lever over to half-cock where the micro switch should complete circuit with the dry power pack. There should be approximately one minute before the major color changes began, which was also the minimum time for gyro run up. Johnny resumed the watching and the waiting.
     How long is a minute?
     Is it the time it takes the fear-frozen trainee, staring glass-eyed at the fumbled grenade to realize that this one at his feet is a dud?
     Or is it the time before the rock-climber, clinging nail and toe to the rock face with the rope snapped suddenly taut, feels it at last slacken and sees the hands gripping safely come into sight?
     Perhaps the greenhorn, rifle a-waver, watching the glimpse of tawny color in the veldt-grass and waiting the thunder and the charge, could say.
     They’d all be wrong. It’s much longer.
     Long enough for Johnny to think of a dozen precautions he could have taken, a dozen better ways to rig this or that. Long enough to worry about whether the gyros were really running up as they should. A thousand queries and doubts piled mountainously upward to an almost unbearable peak of tension till suddenly the browns and greens below flashed a shade lighter and it was time, and the savage snap on the lanyard a blessed relief and total committal.

     In the few seconds after the firing of the prime and before the busy little timer snapped the valves wide open Johnny managed to slip his toes under the jet pedals to avoid accidental firing. At the same time he braced himself as rigidly as possible with aching arms against the walls of the cylinder.
     He saw briefly the flare of the jet reflected off the remnants of his cloud of station stores before deceleration with all its unpleasantness began.
     The lip of the cylinder’s mouth swept up past his helmet as he was rammed deep into the absorbent mass of ribbon chute. This wasn’t a padded contour chair under a mild 3G lift. The chutes took the first shock, but Johnny took the rest the hard way, standing bolt upright.
     He found with some surprise his head was right down through the neck ring and inside the suit proper, his arms half withdrawn from the sleeves, knees buckled to an almost unbelievable angle considering the dimensions of the lower case.
     He had time to hope fervently the cheap expendable motor wouldn’t burn out its throat and send him cart-wheeling through space, or blow the surrounding tanks before the blackout came down.
     He came out of it sluggishly, to find the relief from the dreadful pressure almost as stupefying as the deceleration itself. While his conscious mind screamed the urgency of immediate action, his bruised and twisted body answered but feebly. The condition of complete weightlessness and the springy reaction of the ribbon mass was all that allowed him finally to claw himself out of the cylinder to where he could use the suit jet without fear of burning the precious chutes.
     He was so tired. His muscles of their own accord seemed to relax intermittently, interfering with the control of his movements. Only the sudden sight of the Earth, transformed by a weird illusion of position from a bright goal to an enormous, distorted thing, looming, apparently, over him with glowing menace, spurred his flagging resolution to frantic activity.
     He jetted straight back trailing his string of chutes behind him, then, before the last was free of the cylinder, kicked himself around to assume the original course once more.
     At this stage it was no longer possible, even granted the time, to judge visually how near he was to the atmosphere. The uneasy feeling that he must already be brushing the Troposphere jarred his nerve so that he merely gave himself a short flat-out boost in the right direction before spinning bodily one hundred eighty degrees so that he was traveling feet first.
     Reflected in the curved helmet face, the string of chutes obediently followed-my-leader around a ragged U-shape, the last—the small pilot-chute trailed limply around as he watched.
     There could surely be but a few seconds left before the grand finale. Johnny found he was unconsciously holding his breath, and, as he deliberately inhaled long slow draughts of his already staling air, realized abstractly that he seemed to be attempting to meet his possible end with some degree of dignity if not with resignation, and wondered if he were the exception or the rule.
     Possibly, he thought sardonically, because there is so little room for dignity in our living years, and was mildly surprised at an uncharacteristic excursion into the realm of philosophy.
     There was a faintly perceptible tug on the harness. It was sustained and now there came a definite strain. Reflected for a moment in the helmet face was a glimpse of the lead chute slowly opening out like a gigantic flower.
     Then swiftly, in half a breath the harness coils were tightening about him like steel fingers, the heavy ring at the end of the master shroud clashed against the back of his helmet and began a sickening, thrumming vibration there.
     The harness encompassed his torso like a vise but his legs were unsupported and weighed what seemed a thousand tons. He could feel them stretching. Somewhere a coil slipped a fraction. His arms were jerked suddenly upwards and Johnny knew a sensation he’d never believed possible. At the same time his leaden feet crashed down on the jet pedals. For a few, brief, blessed moments the intolerable extension eased a fraction with the firing of the suit jets.
     He cringed mentally from the thought of what was to come and thought hazily: “This is what the rack was like. This is going to be bad, bad, bad!”
     It was impossible and Johnny went out with the last drop of fuel.

     Somewhere there was a queer coughing sound like wind through a crevice. He strained to identify it but an awful agony swamped him and he fled before it back into the darkness.
     And later still a thumping and a rushing, gurgling sound.

     Dim, grotesque figures moved about him or swooped and hovered over him. He felt an unreasoning fear of them and tried to shut them out. They were holding him down, hurting him. One was pulling and twisting at his arm. He shouted and swore at it telling it to leave him alone, but it ignored him or didn’t seem to hear. There was a sudden dull snapping sound and a little of the pain abated.
     The figures flowed together and swirled around like some great oily vortex but never quite left him.
     Then there was a time when they separated jerkily and became the hazy but definable figures of men in rough seaman’s clothes. Johnny had never heard Breton French before; in his dazed condition the apparently insane gabble might well have been the tongue of another world and gave him little assurance. He hurt so badly and so generally that he could not have determined that he was lying down save for a view of white clouds scudding overhead.
     Some of the men were holding up what looked like a crumpled parody of a man. He recognized it without surprise as the soaking remains of his spacesuit, battered and with tattered shreds of outer cover and insulation hanging in festoons.
     A sharp, bearded face shot into focus abruptly, waving a hypodermic needle. It spoke English and observed passionately either to Johnny or itself that: “Name of a Spanish cow! What is it in men that they must abuse themselves so? Now here is one who was both squeezed and stretched alternately as well as hammered, dehydrated and almost asphyxiated, is it not? This will bear watching. It is alive but there will have to be X-rays in profusion.”
     It danced long sensitive fingers over the welts and bruises and commented bluntly that it was well the fishermen had returned his arms and legs into their sockets before he fully regained consciousness. It muttered and clucked to itself as it used the hypo which Johnny could not feel. “Formidable!”

From FAR FROM HOME by J. A. Taylor (1955)

Rescue Needs


  • Habitable Shelter
  • Life Support
  • Communications
  • Medical Aid
  • Crew Transfer Capability
  • Crew Retrieval Capability

A Space Rescue Vehicle must provide:

  • A habitable haven for the rescued crew
  • Medical aid (facilities and service) for ill or injured personnel
  • Life support for extending crew survival
  • Communication with the disabled crew during the rescue operation
  • Emergency power during the rescue operation
  • Transportation from the scene of the emergency to a final haven of safety

A Space Rescue Vehicle coming to the aid of a distressed vehicle (DV) may need the following capabilities:

  • Collision avoidance with debris generated by the DV
  • Protection from DV radiation sources (nuclear propulsion DV, or DV space station with nuclear power reactor or RTG)
    • Radiation detection sensors for detection survey upon arrival at DV (range of 19 kilometers)
      • Neutron Detectors (proportional counter)
      • Alpha Detectors (proportional counter)
      • Gamma and X-Ray Detectors (collimated scintillation counter)
    • Sensors to determine safe approach corritor to the DV
    • Sensors to identify the nature and source of radiation
  • Ability to dock with a disabled vehicle
  • Ability to arrest the motion of a tumbling vehicle (spin rates up to 4 rpm plus nutation "wobble")
  • Ability to retrieve personnel from EVA and from a DV where docking is not possible

Factors to consider in determining the rescue vehicles requirements:

  • Hazards to the SRV (such as debris or radiation) caused by the distressed vehicle
  • Problems of personnel and equipment transfer to and from the distressed vehicle under docked and undocked conditions; specialized equipment needs include:
  • Means for establishing communication with a mute spacecraft after rendezvous
  • Procedures for gaining emergency access to the interior of a disabled vehicle
  • Equipment for assessing and controlling damage to the disabled vehicle
  • Medical aid for the rescued crew
  • Portable equipment and supplies to provide extended survival on an emergency basis for the crew of the disabled vehicle
  • ΔV needs of the SRV for rendezvous and an external inspection of the disabled vehicle

      Early during the flight of Skylab 2 in July 1973, a potentially serious space emergency developed. Although the crew had safely docked with the space station for their planned fifty-nine-day mission, ground controllers were very anxious about the status of their Apollo ferry ship.

     Faulty fuel valves had prompted the astronauts to shut down two of the four attitude control rocket “quadrants” on the Apollo. Houston officials were concerned that whatever unknown factor had caused these two systems to fail almost simultaneously might spread to the main Apollo rocket engine, essential for bringing the astronauts back to Earth.

     Since the crew were in no imminent danger, and the risk of returning to Earth in a partially crippled spaceship was unknown, the astronauts were instructed to carry on with their flight program as originally scheduled. Meanwhile, back at the Cape, the Apollo command module that had been slated for the third Skylab mission was modified to make it into a space rescue ship. Equipment lockers were removed and two extra couches installed in their place. Two astronauts began brushing up on the contingency flight plan.

     These rescue plans, called for the two astronauts to blast off in the modified Apollo, dock at the side port of the Skylab (if possible, the crippled Apollo already attached to Skylab would be jettisoned, and the rescuers would use the main hatch), and pick up the three stranded astronauts. The five would return to Earth together.

     These plans for the world’s first space rescue flight were soon set aside when ground controllers were able to determine that the two rocket failures were unrelated and that they would not affect the main Apollo engine. Alternate control schemes were devised and tested in simulators so that the astronauts could fly home in their own Apollo even with only two out of four “quads” remaining. The mission went on to a successful conclusion.

     Space rescue had briefly been in the news around the world. But it had long been in the minds of space officials in Russia and America; both countries had suffered tragedies and near tragedies in space and on the ground. Specialists asked themselves what kinds of situations might arise in which the availability of a standby rescue rocket might be able to save the lives of endangered astronauts and cosmonauts.

     In most of the “most likely” space emergencies, engineers had come to the fatalistic conclusion that system failures would result in the loss of the crew within at most a few minutes. Consequently, a rescue ship would not have time to reach them. The lesson was clear: build each spacecraft as reliable as possible, since rescue is impossible. Come home on your own steam, or not at all.

     At least that had been the case in all the real space emergencies which had taken place since the Space Age began. Two unmanned Russian “Vostok” capsules were lost in 1960, one tumbling in orbit and the other incinerated on an off-course reentry. Soyuz 1 brought the first in-flight fatality when its parachute failed. Gemini 8 went out of control in 1966 and Apollo l3 lost power in 1971, but both were recovered, thanks to built-in redundancy systems. Two Soyuz capsules suffered serious breakdowns in 1971; one crew made it back alive and the other didn’t. The two-person crew of Soyuz 15 barely made it back to Earth on emergency batteries and oxygen in 1974 when their linkup with the Salyut 3 space station failed. In none of these cases would a rescue rocket have been able to help.

     With the advent of the Skylab project, NASA was faced with new situations which required new decisions about space rescue possibilities. The main problem—and also the main advantage—of Skylab was the long duration of the missions. The Apollo capsule which was to serve as the ferry ship had not been designed for such long flights, and there was a chance that after sixty days or more in space certain vital electronic or mechanical parts might not function properly. On the other hand, even if there was trouble on the Apollo, the Skylab station would be able to serve as a “safe” shelter in which to wait out the rescue attempt.

     Consequently, NASA implemented the world’s first space rescue service. Procedures were developed for converting the next-in-line Apollo vehicle into a rescue ship. Following the launch of the third and last visit to the Skylab, an extra spacecraft and rocket were made available. If at the end of a Skylab mission the Apollo capsule in space was not working properly, the astronauts in the space station would wait until the rescue rocket could be launched. Depending on when in the mission this decision took place, they would have to wait from two to twelve weeks.

     The two-person crew of the rescue ship would be the commander and pilot of the next planned mission. A rescue of the first Skylab crew would have been flown by Alan Bean and Jack Lousma. The second crew would have been, and almost were, rescued by Jerry Carr and Bill Pogue. The rescue of the last crew would have been entrusted to Vance Brand and Don Lind, members of the Skylab backup team.

     The space agency figured that in the event of a failure (fire, loss of pressurization, atmospheric contamination, et cetera) in the Skylab, the crew would be able to reach the Apollo and return to Earth. In the event of a failure on the Apollo, the crew would wait in the Skylab for rescue. The chances of a simultaneous failure in both Apollo and Skylab were deemed remote; under such conditions the only possible answer was “tough.”

     Although space rescue missions were for all practical purposes impossible in the first decade of manned spaceflight, space planners realized that in the future more ships would be in space and more emergencies were bound to arise. With more launchings every year, the probability of a second ship being in an advanced readiness condition and hence available to rescue the crew of a crippled ship would also increase.

     The rescue ship and the rescued crew might not be of the same nationality. Following the loss of their second crew of cosmonauts, the Russians began to respond to American approaches concerning the possibilities of US and Soviet spaceships being able to provide aid to each other in space.

     These informal exchanges led directly to the Apollo-Soyuz Test Project (ASTP), where an American three-person ship docked in space with a two-person Soyuz (the Soyuz had originally been a three-person ship, but the addition of heavy safety features following the loss of two crews had forced the removal of one of the three couches). Standardization of docking gear (the “androgynous” probe, by which any two ships so equipped can hook up together), oxygen hose couplings, radio frequencies, and emergency terms and procedures, all formed the prime motivation behind this project, which otherwise had little scientific or engineering justification. But someday in the near or far future, Russian or American spacemen may stay alive because this flight was made.

     In the future of manned spaceflight, launching a space rescue rocket might, in some cases, be feasible. The number of these cases will grow as years go by. A crippled ship in Earth orbit might be able to hold out long enough (at least a few days, possibly as much as a month or more) for a rescue ship to be prepared and launched to pick up the stranded crewmen.

     Despite the apparent advantage of stationing standby rescue craft in orbit, when common sense tells us that they are closer to possible ships in distress, most, if not all, rescue missions will of necessity be launched from the surface of the planet. The chance of one ship in space being in position to come to the aid of another vehicle is distressingly small, even if there are dozens of spaceships in orbit.

     The reasons for this involve the esoteric science of “orbital mechanics,” or space navigation. The mathematics of space rendezvous often seem to violate the laws of motion which we are accustomed to on Earth, but they are the laws of the universe and must be followed in space. The penalty for misunderstanding or misapplying these laws can be death.

     A satellite in orbit around the Earth follows an elliptical path which remains in a two-dimensional plane. The Earth’s own daily rotation beneath the satellite creates the often odd-shaped “ground tracks” which on a Mercator projection appear to swing north, then south, then north again. In some\situations, the “subsatellite point” on the spinning Earth will remain fixed, trace out a figure eight, or even double back on itself in a convoluted zigzag line.

     But the twists and turns are an illusion. The satellite is falling through space in a path which curves straight ahead over the Earth’s horizon. It does not deviate to the right or left, although it may gain or lose altitude periodically, reaching apogee (high point) and perigee (low point) at opposite ends of its orbit once per revolution.

     Manned satellites will be in orbits at different altitudes, orbits whose planes are inclined at various angles to each other. The “plane change” maneuver required to match the flight paths of the two approaching ships is extremely expensive in terms of fuel. To change plane sixty degrees, for example, would require expenditure of a weight of fuel equal to that spent on blasting all the way into orbit. Even a change of only ten degrees would require a “delta-V” (velocity change at right angles to the flight path) of an additional twenty percent over that required to reach orbit. Spaceships will not carry that much additional fuel or power for decades to come.

     Nor is it practical to restrict all manned flights to the same orbital plane, which might seem to eliminate the need for a plane-change maneuver during rendezvous. Over periods of several days, the plane of a satellite’s orbit is rotated, or precessed, by the effects of the Earth’s equatorial bulge. The rate of precession depends on the orbital period and eccentricity (distortion from circular) of the particular satellite, as well. as its inclination to the equator. Hence, two satellites in the same plane but with different periods would be affected differently, and the planes of their orbits would gradually diverge. (While it’s true that equatorial orbits would not be affected this way, the launching of manned spaceships into equatorial orbits from launching pads in the Northern Hemisphere involves another “plane change” penalty and is thus probably out of the question for the rest of the century.)

     However, if the rescue ship does not blast into space at the first sign of trouble but instead waits at its launch site on Earth, the Earth’s own rotation will carry the launch pad and the rocket through the plane of each and every satellite orbit twice a day. The rescue ship hence must wait until the precise moment of the “launch window,” then blast into orbit. From the beginning of its flight it is now in plane with its target, and only minor plane adjustments are needed. Rendezvous with a target up to an altitude of several hundred miles can take place within a few hours. The fuel saved from not having to change the orbital plane can be used to catch up with the target satellite faster.

     The next phase of manned orbital operations will involve the Space Shuttle, the reusable orbital ferry vehicle that NASA hopes to have in operation in the early Eighties. Once the Shuttle begins its weekly missions, it is doubtful that a special spacecraft will be set aside for the “rescue watch.” Rather, the Shuttle or the equivalent Russian spacecraft being prepared for the next launching will probably be tagged for the mission if needed. NASA’s turnaround time for refueling and refurbishment is a leisurely two-shift, five-day-week schedule with considerable capacity for emergency speedup.

     A Space Shuttle assigned to a rescue mission would be returned to the checkout building and its payload would be removed. Depending on the number of astronauts to be rescued, up to three additional seats can be added on the lower deck (the shuttle will fly scientific missions with a crew of four and up to three scientist-passengers). The three-man rescue crew may come from a special standby cadre or it might just be the next scheduled commander, pilot, and flight engineer.

     NASA is still working on the actual mechanics of the rescue operation once the two spacecraft have made rendezvous. They may dock back to back and unfurl an inflatable tunnel from one air lock to another, or else their cargo bay air locks may be built with the capacity of hard docking without a tunnel. Or the astronauts on the crippled ship may have to don spacesuits and walk in space, preferably attached to a safety line stretched between the two ships. These operational problems will be complicated by the presence of the scientists and specialists who are not regular astronauts but who have had only a few weeks of flight orientation before their once-in-a-lifetime space research expedition.

     Several engineering projects are now under way to develop parts of the needed rescue equipment. NASA had considered the results of an Air Force project for an expandable air lock/tunnel which could be packed into a canister during launch and unfolded in space when needed. This device, which was originally part of the canceled MOL space station project, was at first scheduled for flight testing on Skylab but has now been deferred to Space Shuttle. NASA is also looking at the design problems involved with an adjustable spacesuit, a suit that does not have to be hand-tailored for each astronaut (custom-made spacesuits are OK today for a corps of fifty astronauts, but in the Eighties there will be hundreds of men and women flying into space every year). The new suit would be able to accommodate a variety of physiques during emergency use in space. Also, the “spacewalk” AMU (Astronaut Maneuvering Unit) backpack which was tested on Skylab will have many applications during regular Shuttle EVAs, as well as use by one of the pilot astronauts to guide the evacuation of the Shuttle during an emergency. Other equipment, plans and procedures are still being considered. These include a “space breeches buoy,” an inflatable pressurized canister large enough to hold one or more astronauts but small enough to operate out of the standard air lock.

     With all the rescue ships and rescue equipment, there still may be cases where the astronauts will be in immediate peril. The spacecraft may be completely uninhabitable, or there may be no rescue ships ready soon enough.

     Any spot on Earth, from the Arctic to the Sahara, can be more hospitable to a man than space, although freezing or dehydrating are as fatal as suffocation. More important, any spot on Earth can be reached by normal emergency rescue teams who cannot get into space. The problem, then, is for the endangered spacemen to reach the ground.

     But how could this be done? Stepping out of the cabin in orbit would leave the space-suited astronaut in orbit alongside. Even if he could get onto a collision course with Earth, there remains the fate suffered by countless meteorites every day: incineration. Once past that point, the last, delicate stage would involve hitting the ground softly enough to survive.

     Bizarre as it may seem, many space designers consider this “orbital bail-out” option to be simple, reliable, and effective. It would require, of course, some special types of equipment to overcome the three main problems: a man would need his own retro-rocket. his own heat shield, and his own parachute. Can that be done inside of stringent weight and size requirements?

     NASA briefly examined a number of proposals in the mid-Sixties which described various ways of meeting these requirements. Although most projects were soon terminated because of technological problems, and NASA eventually decided that for the foreseeable future it would be safer to strengthen each spacecraft rather than build the option of “bail-out,” these systems make a lot of sense when coupled with the Space Shuttle.

     Essentially, the system called for a special kit, usually about two hundred pounds and the size of a steamer trunk, which could support one astronaut. They dons their spacesuit and leaves the crippled spaceship. The disk-shaped heat shield would be assembled with the astronaut sitting in the middle and a silica-plastic foam material filling in an inflated mold. The foam would harden in minutes and the astronaut would strap a small solid fuel rocket motor on his chest.

     Lining up facing forward into the apparent ground motion of his flight, the astronaut would fire the small rocket to knock himself out of orbit. They then jettisons the empty rocket shell and spins his back toward the atmosphere. In his spacesuit they may have only thirty minutes of oxygen, but that’s more than enough. By the end of that time they will be in the atmosphere or dead.

     The heat of reentry would be dissipated by the ablative heat shield, as the fragile lifeboat undergoes G-forces ten times above normal. Contrary to popular belief, the tremendous heats are not the result of air blast friction, which would tear the craft apart. Rather, they are caused by the compression of air pushed in front of the heat shield and trying to get out of its way. Consequently, the highest temperatures are not on the surface of the heat shield but are in the super-hot plasma about a foot in front of the “space raft.”

     Once the astronaut has reached terminal velocity, and is falling through the atmosphere at about six hundred miles per hour, they will have to escape from his safety cocoon and use his last gadget, an ordinary parachute. A special survival kit. and beacon would keep him alive wherever they might land and would allow rescuers to find him.

     Risky as this technique sounds, it would be preferable to situations in space which threaten certain death. Hopefully, the system will be tested unmanned and with volunteers before it is needed for an emergency.

     The day may also come when large permanent space stations are circling the Earth. Crews will be rotated through flights of Space Shuttles carrying thirty-man passenger units in their cargo bays. But the chances are that there will not be enough ships available to evacuate the entire crew of a station in an emergency. In that case, these individual bail-out kits, or possibly one section of the space lab which has a heat shield and life-support and control systems (and which normally may serve as a storeroom or lounge), would be needed to evacuate the entire crew. These stations are fifteen years in the future, but rescue planning and testing will begin soon.

     After all the dangers of the fiery return to Earth, the next most potentially dangerous stage of any space mission is the rocket launching. Hundreds of tons of high-energy fuels, tremendous combustion temperatures and pressures, and unpredictable weather and atmospheric conditions all combine to worry safety planners.

     Two methods of launch rescue have been developed. The pilots could use ejection seats (like the Russian Vostok and the American Gemini programs), or an “escape tower” could fire its rocket and pull the entire capsule free of the faltering launch vehicle (this was used for the Mercury. Soyuz, and Apollo spacecraft). Once away from the rocket, the men are recovered by parachute and picked up by waiting emergency teams.

     But like modern jetliners, the future Space Shuttle will normally not have launch abort rescue facilities. During the initial glide tests, and later on the first few test launches into orbit, the four-man crew will have standard ejection seats. Once operational flights begin, however, the heavy ejection seats will be removed.

     That decision is not a particularly risky one, since the possibilities of launch aborts have been carefully studied. The Space Shuttle will have two solid fuel strap-ons and three main liquid fuel engines. The solids have triple-redundant igniters which have never failed in fifty flights of similar systems in use today. If the liquid fuel engines do not ignite, the solids will not generate enough thrust to lift the vehicle and the crew would sit tight and wait out the burn. If there is a failure or degradation of three nominal liquid fuel engines, the Shuttle would head out to sea, jettison the solids, and come back for a landing airplane-style at the runway near the launch site.

     The manned exploration of the lunar surface will create new problems for space rescue of disabled vehicles and stranded astronauts. Despite the feasibility of some remarkable rescue options, the Moon remains a hostile and unforgiving environment.

     The problems of rendezvous of two manned ships orbiting the Moon in different planes is as serious as the problem near the Earth. First, the launch of a rescue ship must be made from the Earth, since extensive launching sites on the Moon are not likely for a century. The flight time of such a rescue ship would exceed sixty hours. If in the meantime the endangered spacemen are on a collision course with the Moon, no personal retrorocket or heat shield will save them from smashing into the surface at several thousand miles per hour.

     Nor could a rescue ship be launched from the Moon, even if one were available, except in the most exceptional situations. The Moon’s period of rotation is twenty-eight days, not twenty-four hours like the Earth’s. A potential rescue rocket on the Moon’s surface is carried by the Moon’s rotation through the orbital plane of every Moon satellite, but it takes up to fourteen days to do so. If the rocket is not already in the orbital plane of the crippled ship, it may take a week or more for a launch window to occur.

     But the situation which in Earth orbit rules out the rescue of one orbiting ship by another because of the great amounts of fuel required to change planes is somewhat different around the Moon. First of all, any orbiting ship does carry a great amount of fuel: the fuel required to blast out of lunar orbit on the way back to Earth. That same fuel could be used in an emergency to alter the plane of the orbit enough to match trajectories with nearly any other satellite circling the Moon. The rescue ship would not then have enough fuel to return to Earth, but would have to wait the time of flight of a second rescue ship from Earth, carrying the extra fuel for the return to Earth.

     The rescued Moon satellite could be another lunar spaceship or it could be a single space-suited astronaut. Whereas in Earth orbit the prime goal of an endangered astronaut is to use the “bail-out kit” to get down to the surface of the Earth, an astronaut in trouble on the lunar surface must have a way to get up into lunar orbit where the possibility of rescue becomes larger.

     One way of accomplishing this is through using a special lunar exploration and transportation device modeled after the Bell “Flying Belt” and the AMU (Astronaut Maneuvering Unit). Under normal conditions the “flying platform” would carry one of two men across the lunar surface. But in an emergency the device should be designed with the added capability to be fully fueled (perhaps from the tanks of a crippled Lunar Module or from a fuel cache) and to be able to carry one or two men into a stable lunar orbit. The exact plane of the orbit would be picked in order to make rendezvous with the orbiting mother ship most optimal. (The Moon’s slow rotation rate gives no advantage to “launching eastward,” a trick used on Earth to gain additional velocity by flying in the direction of the Earth’s rotation. Moon ships can blast off into lunar orbit in any direction.)

     Once in orbit and on board the mother ship, the astronauts could presumably wait out the rescue ship from Earth. This need not even be a manned ship, just a robot tanker with enough fuel to allow the still-operating lunar orbit ship to refuel and return to Earth. Moon rescue would become an established fact.

     The rescue of crippled ships on fast trajectories far from the Earth (on an interplanetary voyage, for example) will be impossible for decades if not centuries. The delta-V requirements for another ship to be launched in pursuit, get there fast enough, slow down enough to match velocities, and have any payload left to do any good, are vastly beyond the capabilities of any spacecraft even being dreamed about for use before the end of the century. A spaceship launched beyond the Moon cannot count on rescue or any kind of physical aid from Earth.

     Besides the old standby of redundant spacecraft systems, a new approach would quite obviously call for redundant spacecraft, expeditions of multiple vehicles which could in an emergency aid each other. For example, two ships with ten men in each might be launched on a two-year expedition to Mars. In the event of a catastrophic failure on one of ‘the ships, the crew would transfer to the other, most of the scientific instruments would be jettisoned to make room, and the mission would be abandoned. (Although not entirely: once you’re headed for Mars, the quickest and easiest way home is via Mars. It is nearly impossible to turn around and reverse your course; Earth wouldn’t be where you left it anyway. When Apollo l3 was aborted halfway to the Moon, it still had to fly past the Moon to get back to Earth.)

     In the future, the problems of space rescue will have to be approached at many levels. Spacecraft designers will concentrate on making critical spaceship systems as reliable and redundant as possible, while also building in to each ship the capacity for extended rescue-type missions. When a spaceflight is taking place, controllers will alert other space-faring nations to be ready, if needed, to mount a space rescue mission. Special equipment like AMU’s, bail-out kits, and lunar flying platforms will give crewmen the option to abandon their crippled spacecraft and try to reach rescue forces on their own power.

     There are already enough graves on Earth of brave men whose luck ran out ion the road into or back from space. Although no single death was inevitable or unavoidable, no flight was ever one hundred percent safe. As the space frontiers expand, it is tragically certain that more men will die—of accident, equipment failure, misjudgment, even natural causes—in outer space, or on other worlds. Spaceships and crews will be lost in the depths of space, in close-Earth orbits, or on their final return into the home planet’s life-giving atmosphere. Space rescue systems will try to make these occasions as rare as possible.

From SPACE RESCUE by James Oberg (1975)

Rescue Equipment

The easy way to rescue is to dock with the DV and let the stricken astronauts in. This is why one important rescue item is international standards for universal docking ports. It greatly simplifies a rescue if a Space Rescue Vehicle from Nation Alfa can easily dock with a distressed vehicle from Nation Bravo. If the freaking DV has incompatable docking ports: you have spend precious time to isolate a sealable room on the distressed ship, cut a blasted hole in the hull, and insert an Attachable Docking Fixture.

But first, the DV is probably spinning like a top, which will make docking practically suicide. So it is time to use despin equipment make the DV settle down.

If it proves impossible to despin the DV and thus impossible to dock, you will have to goto the extra effort of EVA. Break out the EVA space suits or space pods and use a breeches buoy to evacuate the distressed astronauts.

If EVA is not indicated you'll have to do it the hard way with portable airlocks and other heavy-duty gear.

Space Rescue Vehicle Requirements
itemmass (kg)
Communication and Survey Equipment318
Despin Devices113
Soft Docking Fixture113
Attachable Docking Fixture363
Portable Airlock726
EVA Suits32
AMU Backpack68
Manipulator (Shirtsleeve)907
Transfer Capsule227
Sampling and Analysis Kit23
Damage Control Equipment68
Remote Manipulator454
Medical Kit27
Extended Survival Kit227
Tethers (Umbilicals)20
Personnel Carriers5
Miscellaneous and Spares91

Docking Equipment

This is equipment needed if the DV has incompatible or wrecked docking port, or if the spin on the DV cannot be stopped.


H. Entry to DV

     As already indicated, entry to the DV from EVA may require EVA operations to force entry hatches, the removal of modules already docked against the entry hatch, etc. The use of manipulators of either open platform or capsule type may be required in this operation. One other consideration applies in the instance when the DV hatch through which entry is to be made is not equipped with a working airlock. When entry under EVA conditions is to be made into a DV which has retained all or some of its atmosphere, and where continued retention of the atmosphere is essential, an airlock cycle must be performed either in a nominal airlock or by evacuating and repressurizing the DV compartment behind the entry hatch. If compartment pressure cycling is infeasible due to lack of functioning equipment, or due to the presence of a shirtsleeve crew (who you presumably do not want to kill by asphyxiation), a portable device may be required which can serve as an airlock. Such a portable airlock (PAL) could be of expandable design in order to reduce stowage volume requirements in the SRV and could have other additional functions. It could, for example, be utilized between docked spacecraft to serve as an atmospheric contamination barrier between DV and SRV. Equipped with appropriate chemical spray systems, it would also prevent biological contamination of the SRV, if the DV emergency has created such a hazard. Used as a BOD or as a quarantine device it would require more extensive EC/LS provisions,

     A conceptual arrangement of a PAL sized for two astronauts is shown collapsed for stowage in Fig. H-20. The flexible center section, made of material that can be folded, is extended by pressurization to a length long enough to accommodate a suited astronaut in a stretched-out position.

     The PAL consists of two active ring-and-cone assemblies, an extendible cylindrical member, a cylindrical structure which encloses the collapsed flexible member, and a breathing and pressurization subsystem. The two active ring-and-cone assemblies incorporate the docking mechanism and the hatches and are connected by the folded flexible cylindrical member. The airlock thus permits entry into the DV by an astronaut operating in an EVA mode or by direct transfer to the DV from a rescue vehicle docked to the opposite end of the portable airlock. A typical flexible material having the required structural and packaging properties is the Goodyear "Airmat." The PAL is extended initially by using the pressurization system which also provides the breathing atmosphere.

     The docking hatches combined into the docking mechanism at each end of the portable airlock are identical in size and provide a clear 5.0 ft (1.5 m) diameter opening for transfer of equipment. The two docking mechanisms are fastened together in the stowed position by the rigid cylindrical structural member which encloses the collapsed flexible member. The rigid cylindrical member incorporates a circumferential joint, located midway along its length, which is held together by spring loaded locks which are released either electromechanically or by the internal pressure used to extend the airlock into the operating position. The rigid cylindrical member also provides protection for the extensible material during stowage. Possible methods for retracting the airlock after use include telescopic tubes, cable retraction devices, extendible booms, etc. The stowed volume of the airlock is about 380 ft3 (10.8 m3) and its weight is estimated at about 1600 lb (725.7 kg).

H. Docking Interface

     A brief conceptual analysis was undertaken to determine whether SRV's could be equipped with soft docking fixtures capable of reducing the difficulty of docking to a DV with some residual wobble. The analysis was non-quantitative; stress analysis was not performed and the design was not matched to specific values of DV motion.

     The soft docking fixture shown in Figure H-22 is configured to accommodate slight motions between the rescue vehicle and the DV. If the DV motions are greater than can be accommodated by the docking fixture, these motions must be reduced to a tolerable level. The concept calls for flexibly mounting the North American Rockwell docking design with a neuter docking device and a passive ring. The docking port on the DV is assumed to be a passive ring assembly. This concept could be modified into a ring/cone assembly which can be mated with another active ring/cone docking assembly to form a complete neuter docking subassembly.

     Further study of this concept is required to derive methods for extending the flexible bellows toward the DV shell to provide a pressure seal and the correct stiffness at the flexible connection to minimize vehicle dynamic interactions resulting from differential vehicle motion. The weight increment of this type of docking fixture over the conventional design would be about 250 lb.

     A damaged spacecraft implies the possibility of a situation where docking facilities are unavailable. If a space station is taken as an example, many of its docking ports will be occupied by experiment modules. Other ports may have logistic vehicles such as space tugs or the EOS docked to them. Finally, the emergency situation calling for rescue may have destroyed some of the ports or may have closed the passage between them and the space station compartment which the rescue crew is attempting to reach. EVA airlocks may be provided on the station but may not have been equipped with docking fixtures. The SRV may thus be faced with the necessity of creating an opening against which it could dock. In either case, that of an opening already available such as an EVA air lock, or that of an opening that must be cut into the hull, a docking fixture must somehow be placed over the opening to permit SRV docking. The concept of such a portable docking fixture was briefly investigated.

     The portable, attachable docking fixture shown in Figure H-23 permits docking to a distressed vehicle via an EVA port. For purposes of this study, a 6-ft diameter opening, 12 inches larger than the standard hatch opening, was assumed. This larger opening permitted the use of the North American Rockwell docking design with minor modifications, and also permitted the use of ramp-shaped docking pawls identical in cross-sectional shape to the North American Rockwell docking cone. Space is also available for a standard 5 ft diameter hatch for transfer of personnel and cargo. The portable docking fixture is secured within the 6 ft diameter opening by the eight docking pawls located radially about the opening. The pawls are engaged initially at the pawl tips: continued movement of the fixture farther from the port opening causes the docking pawls to rotate over center about the pivot points as pressure is exerted on the ramp portion of the pawl. The pawls continue to rotate about their respective pivots until the end points of the ramps have been reached; the spring-loaded pawls then snap into place behind the DV opening, thus securing the fixture between the back face of the pawl and the docking fixture seal face. An inflatable seal between the seal face and the DV port area prevents pressure loss as the DV is repressurized. Retraction of the locking devices to permit withdrawal is provided through the use of electromechanical or completely mechanical devices.

     The basic concept can also be applied to an opening specifically cut into the pressure hull of a space vehicle, providing the structure had initially been designed to permit this.

Despin Equipment

Trying to dock your space rescue vehicle to a spinning distressed vehicle is insanely dangerous. Especially since the blasted DV is probably not just doing a pure spin, it probably has a fierce nutation as well (fancy word for "wobble"). If things are really bad the DV is not just spinning, it is tumbling (simultaneously doing spins around more than one axis, instead of just spinning around a single axis)

They estimate that a DV will probably be spinning at 4 rpm or slower, unless the attitude jets got stuck at maximum throttle or something.


A yo-yo de-spin mechanism is a device used to reduce the spin of satellites, typically soon after launch. It consists of two lengths of cable with weights on the ends. The cables are wrapped around the final stage and/or satellite, in the manner of a double yo-yo. When the weights are released, the spin of the rocket flings them away from the spin axis. This transfers enough angular momentum to the weights to reduce the spin of the satellite to the desired value. Subsequently, the weights are often released.

De-spin is needed since some final stages are spin-stabilized, and require fairly rapid rotation (around 50 rpm. Some, such as Pioneer, rotated at over 600 rpm) to remain stable during firing. (See, for example, the Star 48, a solid fuel rocket motor.) After firing, the satellite cannot be simply released, since such a spin rate is beyond the capability of the satellite's attitude control. Therefore, after rocket firing but before satellite release, the yo-yo weights are used to reduce the spin rates to something the satellite can endure (often 2-5 RPM). Yo-yo de-spin systems are commonly used on NASA sub-orbital sounding rocket flights, as the vehicles are spin stabilized through ascent and have minimal flight time for roll cancellation using the payload's attitude control system.

As an example of yo-yo de-spin, on the Dawn Mission, roughly 3 kg of weights, and 12 meter cables, reduced the initial spin rate of the 1420 kg spacecraft from 46 RPM to 3 RPM in the opposite direction. The relatively small weights have a large effect since they are far from the spin axis, and their effect increases as the square of the length of the cables.

Yo-yo de-spin was invented, built, and tested at Caltech's Jet Propulsion Laboratory.

Yo-yo hardware can contribute to the space debris problem on orbital missions, but this is not a problem when used on the upper stages of earth escape missions such as Dawn, as the cables and weights are also on an escape trajectory.


Sometimes only a single weight and cable is used. Such an arrangement is colloquially named a "yo-weight." When the final stage is a solid rocket, the stage may continue to thrust slightly even after spacecraft release. This is from residual fuel and insulation in the motor casing outgassing, even without significant combustion. In a few cases, the spent stage has rammed the payload. By using one weight without a matching counterpart, the stage eventually tumbles. The tumbling motion prevents residual thrust from accumulating in a single direction. Instead, the stage's exhaust averages out to a much lower value over a wide range of directions.

In March 2009, a leftover yo-weight caused a scare when it came too close to the International Space Station.

From the Wikipedia entry for YO-YO DE-SPIN

I.2.2.1 Sources of Uncontrolled Motion

There exist several potential causes which can induce appreciable spin or tumbling of spacecraft such as the Space Station or the EOS. These are:

  • Escaping spacecraft atmosphere
  • Malfunctioning reaction control thruster or momentum exchange devices (reaction wheels or control moment gyros)
  • Malfunctioning de-spin mechanism
  • Separation from counterweight in the artificial G mode of the station/base
  • Collision with orbiting debris, meteroids, or other spacecraft
  • Docking impact
  • Loss of attitude control system (power failure, etc. ) in low earth orbit
  • Movement or redistribution of masses within the spacecraft (crew or payload)

The first six causes listed above were examined in Ref. 1-3 where it was concluded that each cause may induce a 3 to 4 rpm tumble in a space station. This appears to be a reasonable estimate for. the Space Station as well as other large spacecraft. A detailed study of the Space Tug or EOS was not made. The seventh cause listed above is particularly significant if the spacecraft attitude control sys tem failure occurs within the atmosphere. Tumbling will certainly result under such conditions with the spin stabilizing about the axis of maximum moment of inertia. Although the tumbling rate can have any value, a range of 1 to 4 rpm is probable, based on observed tumbling rates of spent booster stages in low earth orbits.

The induced tumble of the spacecraft may be about an arbitrary axis initially but will tend to approach pure spin about the major principal axis of the vehicle if there is any energy dissipation in the system. Such energy dissipation may be caused by internal sources (sloshing fluids, structural damping) or external sources (atmospheric friction, induced eddy currents, etc.), and will tend to decrease the vehicle nutation (wobble) as well as spin. The amount of energy dissipation may or may not be sufficient to provide a noticeable effect over a single orbital period.

I.2.2.2 Reducing Unstable Motion

A tumbling or spinning spacecraft can be despun by application of an external torque, by energy dissipation within the spacecraft or by inertia augmentation i.e., the extension of booms with tip masses or the deployment of cable-connected masses (yo-yo). A rescue vehicle of a size comparable to or greater than the distressed spacecraft could also conceivably grapple the tumbling vehicle and exert a torque on the vehicle to despin it. Such a procedure, however, is not recommended for the general case because the resulting motion of both spacecraft would be very difficult to predict and control.

(ed note: complicated equations omitted, refer to the report if you really want them)

The results of the above simplified analyses suggest that a yo-yo method may be a practical means of stopping a space station or a smaller vehicle tumbling in orbit. The cable length is on the order of 1200 ft if the despin weight is 100 lb. Centrifugal force aids the unwinding of the cable and the mass can be released from the vehicle after unwinding. If the mass is not released, the system may achieve gravitational stabilization in attitude, or perform slow oscillations about the local vertical. As an alternate solution, small rockets can, of course, also be used but will probably be heavier in total weight.

I.2.3 Conclusions and Recommendations

The problem areas associated with spacecraft tumbling and SRV docking to tumbling, distressed vehicles have been briefly examined and identified. The examination of the possible tumbling causes suggested that a 4 rpm spin is a likely value for the space station. It was concluded that:

  1. Hard docking to a tumbling (spinning) spacecraft does not appear feasible because the target is likely to have complex motions not easily matched by the SRV.
  2. Self-contained despin solutions should be emphasized. The despin devices should be internally or externally activated and located to oppose spin about the principal axes. Externally attachable devices by the SRV should also be considered.
  3. The feasibility of hard docking to a tumbling DV should be reexamined if the SRV can be rotated about an axis passing through a docking port and the DV can have a docking port along each of the principal axes (or very close to them).
  4. Should spin or tumble of the DV be reduced to a relatively low value, hard docking or grappling may be attempted. The grappling and docking mechanisms should
    1. be simple, lightweight and reliable
    2. not damage target or SRV
    3. have positive target capture and retention
    4. be capable of self-disengagement
    5. be operable with some misalignment between target and rescue vehicle
    6. provide for multipoint contact and large energy absorption capability
    7. have final (docked) configuration dynamically stable and controllable.

H. Despin Devices

     The causes and magnitudes of uncontrolled motion of a distressed vehicle have been discussed in Appendix I. Action to reduce this uncontrolled motion can be taken by either the DV or the SRV. It is also possible to postulate a scheme for despinning which, in the event of total failure of DV command systems, and/or of the DV crew, could be activated by the SRV either remotely or by sending a crew in EVA.

     Three basic schemes for despinning were considered; the application of external torques, energy dissipation within the DV, and inertia augmentation. All three schemes lend themselves to pre-positioned devices within or on the DV; only the first and the third method could also be applied by the SRV.

     Examples of external torques are the use of reaction control systems already provided on the DV, or the application of external thrusters attached by the SRV crew. If the size relationships between SRV and DV are appropriate, grappling mechanisms on the SRV may be able to couple the two vehicles to allow the propulsive capability of the SRV to reduce the motion.

     Without provision of special equipment, energy dissipation within the DV is often available in the form of sloshing propellants or magnetic forces such as eddy forces. Such inherent dissipating processes tend to act very slowly, possibly requiring weeks to produce the desired stabilization. Special energy absorbers in the form of fluid hoops are also conceivable, which may speed up the stabilization process.

     Inertial augmentation can be provided by extendable masses on booms or weights on cables (Yo-Yo System).

     A brief analysis was performed to size two such feasible systems which also offer the possibility of being brought to the DV by an SRV and attached either manually by a crew or by a remote-controlled manipulator. For both systems, the characteristics of the uncontrolled DV motion must be known to reasonable accuracy to permit the sizing of the control forces and the proper locating of the attachment point. The mass-on-cable and the rocket thruster concepts were selected for analysis and were applied to a tumbling space station.

     The assumptions concerning the characteristics of the space station were as follows:

  • Weight of the station = 120, 000 lb
  • Motion around the major axis of rotation
  • Rate of motion = 4 rpm

     It was also assumed that attachment aids had been provided on the station in anticipation of the need.

     If the tumbling mode requires despin device attachment at unpredictable positions, the concept of prepositioned despin aids is not applicable. Further study of this problem is necessary prior to the selection of any de spin device. Undesirable Vehicle Motion

The potential hazards of explosion, vehicle collisions, and reaction control system malfunctions could result in spinning or tumbling of a DV. Preliminary estimates (Appendix 1-2) indicate that large spacecraft, e. g., a space station, could have residual spin rates up to 4 rpm. Pure spin, however, is unlikely. It would probably exist only if the DV attitude control system was still functioning or after the elapse of a long time.

Prior to any attempted physical contact between the SRV and DV, it would first be necessary to characterize the DV motion. The DV spin rate and axis of rotation and nutation (wobble) rate and angle would have to be known. One possible method for such DV motion characterization requires at least three retro-reflectors suitably positioned beforehand on the outer shell of the DV (at a weight penalty of 2 lb) and a scanning laser radar and computer system on board the SRV (at a weight of approximately 30 lb and a volume of approximately 2 ft2). Such a system would have an effective range of approximately 1 mile.

If an SRV attempted to dock with a spinning DV in the plane of spin, an SRV thrust-to-weight ratio of approximately 0.5 (i.e., incredibly powerful engines) would be required because of centrifugal force effects. This is not feasible for Integrated Program vehicles (EOS, Space Tug), because they do not have thrusts of this magnitude.

If, for docking purposes, an SRV approached a spinning DV along the spin axis, the centrifugal force problem is avoided. However, the SRV and DV docking ports must both be on the axis of spin, and even then the docking torques would be greater than normal. Further, a docking port located in the spin axis is unlikely except in the case of an intentionally rotating space system (with a randomly spinning DV, the spin axis can be anywhere).

If the DV motion was not pure spin (i.e., contained "wobble"), a complex SRV control problem occurs in attempting to match the wobble pattern of the DV. Therefore, the feasibility of approach along the spin axis is also questionable unless the motion of the DV can be reduced to an acceptable level.

Means for reducing undesirable DV motion to acceptable limits for docking or EVA transfer involve, of course, either the activation of some momentum transfer device on the DV itself or a built-in tumbling-arrester system in the SRV. The latter approach has often been mentioned as a desirable SRV capability, but no known practical schemes have been evolved to date (1971) for vehicles of the size envisioned for the Integrated Program. Examples of the former approach include a mass on a cable (yo-yo) or a rocket system, either appropriately emplaced beforehand on the DV or attached by an SRV crew at the scene of the emergency (in EVA or manipulator-assisted operations).

For the case of a 120,000-lb space station with motion at 4 rpm about its major axis of rotation, a yo-yo system consisting of 1200 feet of cable and a 100-lb weight would be adequate (total weight about 150 lb, total stowage volume about 3 ft3). Alternatively, a rocket thrust system with approximately 70 lb thrust (310 N) and burning approximately 30 minutes could also reduce the DV motion (total weight about 460 lb, total stowage volume approximately 7 ft3 ).


It was perhaps inevitable that when the long-awaited indication of intelligent life at last appeared the majority of the ship's observers were looking somewhere else, that it did not appear in the batteries of telescopes that were being trained on the surface or on the still and cine films being taken by Descartes' planetary probes, but on the vessel's close approach radar screens.

In Descartes' control room the Captain jabbed a button on his console and said sharply, "Communications...

"We have it, sir," came the reply. "A telescope locked onto the radar bearing-the image is on your repeater screen Five. It is a two- or three stage chemically fueled vehicle with the second stage still firing. This means we will be able to reconstruct its flight path and pinpoint the launch area with fair accuracy. It is emitting complex patterns of radio frequency radiation indicative of high-speed telemetry channels. The second stage has just cut out and is falling away. The third stage, if it is a third stage, has not ignited. . . It's in trouble!"

The alien spacecraft, a slim, shining cylinder pointed at one end and thickened and blunt at the other, had begun to tumble. Slowly at first but with steadily increasing speed it swung and whirled end over end.

"Ordnance?" asked the Captain.

"Apart from the tumbling action," said a slower, more precise voice, "the vessel seems to have been inserted into a very neat circular orbit. It is most unlikely that this orbit was taken up by accident. The lack of sophistication-relative, that is-in the vehicle's design and the fact that its nearest approach to us will be a little under two hundred miles all point to the conclusion that it is either an artificial satellite or a manned orbiting vehicle rather than a missile directed at this ship.

"If it is manned," the voice added with more feeling, "the crew must be in serious trouble ...

"Yes," said the Captain, who treated words like nuggets of some rare and precious metal. He went on, "Astrogation, prepare intersecting and matching orbits, please. Power Room, stand by."

As the tremendous bulk of Descartes closed with the tiny alien craft it became apparent that, as well as tumbling dizzily end over end, the other vessel was leaking. The rapid spin made it impossible to say with certainty whether it was a fuel leak from the unfired third stage or air escaping from the command module if it was, in fact, a manned vehicle.

The obvious procedure was to check the spin with tractor beams as gently as possible so as to avoid straining the hull structure, then defuel the unfired third stage to remove the fire hazard before bringing the craft alongside. If the vessel was manned and the leak was of air rather than fuel, it could then be taken into Descartes' cargo hold where rescue and first contact proceedings would be possible—at leisure since Meatball's air was suited to human beings and the reverse, presumably, also held true.

It was expected to be a fairly simple rescue operation, at first...

"Tractor stations Six and Seven, sir. The alien spacecraft won't stay put. We've slowed it to a stop three times and each time it applies steering thrust and recommences spinning. For some reason it is deliberately fighting our efforts to bring it to rest. The speed and quality of the reaction suggests direction by an on-the-spot intelligence. We can apply more force, but only at the risk of damaging the vessel's hull—it is incredibly fragile by present-day standards, sir."

"I suggest using all necessary force to immediately check the spin, opening its tanks and jettisoning all fuel into space then whisking it into the cargo hold. With normal air pressure around it again there will be no danger to the crew and we will have time to..."

"Astrogation, here. Negative to that, I'm afraid, sir. Our computation shows that the vessel took off from the sea-more accurately, from beneath the sea, because there is no visible evidence of floating gantries or other launch facilities in the area. We can reproduce Meatball air because it is virtually the same as our own, but not that animal and vegetable soup they use for water, and all the indications point toward the crew being water breathers."

For a few seconds the Captain did not reply. He was thinking about the alien crew member or members and their reasons for behaving as they were doing. Whether the reason was technical, physiological, psychological or simply alien was, however, of secondary importance. The main thing was to render assistance as quickly as possible.

If his own ship could not aid the other vessel directly it could, in a matter of days, take it to a place which possessed all the necessary facilities for doing so. Transportation itself posed only a minor problem—the spinning vehicle could be towed without checking its spin by attaching a magnetic grapple to its center of rotation, and with the shipside attachment point also rotating so that the line would not twist-shorten and bring the alien craft crashing into Descartes' side. During the trip the larger ship's hyper-drive field could be expanded to enclose both vessels.

His chief concern was over the leak and his complete ignorance of how long a period the alien spacecraft had intended to stay in orbit. He had also, if he wanted to establish friendly relations with the people on Meatball, to make the correct decision quickly.

He knew that in the early days of human space flight leakage was a quite normal occurrence, for there had been many occasions when it had been preferable to carry extra air supplies rather than pay the severe weight penalty of making the craft completely airtight. On the other hand the leak and spinning were more likely to be emergency conditions with the time available for their correction strictly limited. Since the alien astronaut or astronauts would not, for some odd reason, let him immobilize their ship to make a more thorough investigation of its condition and because he could not reproduce their environment anyway, his duty was plain. Probably his hesitancy was due to misplaced professional pride because he was passing responsibility for a particularly sticky one to others.

(ed note: as it turns out, the alien's pilots weird physiology is such that they have to be constantly spinning or they die.)

From MAJOR OPERATION by James White (1966)

Breeches Buoy

in the wet navy, a Breeches Buoy is a rope based contraption used to transport people from a wrecked ship to a rescue vehicle. In a rocketpunk universe, this would be used for space rescue. If the rescuee knows how to don and handle themselves in a space suit, the Breeches Bouy can be little more than a cable shot by a line-throwing gun.

In different circumstances if the rescuee is a clueless ground-gripping civilian who thinks that a space suit is a sort of halloween costume, or if the rescuee is too severely injured to be capable of getting into a suit, more elaborate equipment is needed. This usually takes the form of some sort of inflatable pressurized bubble just big enough to hold a patient strapped to a stretcher.


A breeches buoy is a crude rope-based rescue device used to extract people from wrecked vessels, or to transfer people from one location to another in situations of danger. The device resembles a round emergency personal flotation device with a leg harness attached. It is similar to a zip line.

The breeches buoy was usually deployed from either ship to ship, or ship to shore using a rocket, kite system, or a lyle gun, and allowed single person evacuations. A line is attached to the ship, and the person being rescued is pulled to shore in the breeches buoy which rides the line similar to a zip line.

From the Wikipedia entry for BREECHES BUOY

Glossary of Acronyms

AL Airlock
AMU Astronaut manuvering unit
BOD Bail-out Device (BOW or stranded BOR)
BOR Bail-out and Return device
BOW Bail-out and Wait device
DV Distressed Vehicle
EC/LS Environmental Control and Life Support system
EVA Extravehicular Activity
PAL Portable Airlock
SRV Space Rescue Vehicle

G.3.2 Personnel Carrier and Auxiliary Aids

     The transfer of injured personnel from the distressed vehicle to the rescue vehicle without further injury or damage can be a significant factor in assuring containment of the medical situation. Injuries requiring careful handling and immobilization include fractures and/or dislocations. Such injuries can result from moving in a weightless environment, body acceleration during maneuvering or docking operations, meteoroid penetration of the spacecraft cabin or the spacesuit during EVA, and mechanical injuries arising from explosive decompression, explosions, and walking on extraterrestrial surfaces

     The ideal characteristics of a device to transport an individual with such injury include:

  1. Light weight, with minimum storage volume
  2. Provision for body and limb restraints
  3. Protection against bumping interior surfaces while being moved
  4. Handles or grips, and tie-down provisions to the spacecraft interior

     One concept combining these characteristics visualizes a stretcher-type inflatable air mattress with bumping shields, restraint belts and hand holds, and compressed air bottle. Restraint belts would be provided for both the torso and for each leg.

     To provide full immobilization for fractures and/or dislocations, the use of pneumatic splints could supplement this personnel carrier. The storage volume of the carrier uninflated is estimated at 0.25 cubic foot (0.007 m3) with a total weight of under 10 pounds (4.5 kg).

G.3.3 Other Equipment With Medical Utility

     Medical conditions on board the DV may require means for quarantining and/or decontaminating members of the DV crew and/or members of the rescue crew. Appendix H discusses two equipment items which could have secondary application in this context. The transfer capsule was conceived as a device to allow transfer of ill or injured personnel unable to don pressure garments for EVA transfer when docking was infeasible. This capsule, equipped with an independent environmental control system, could be docked against the SRV during the return-to-haven phase while serving as a one-man quarantine station. The portable airlock could hold two men for this purpose. This airlock could also be equipped to perform biological decontamination functions for personnel transferring in a docked situation or during a quarantine period.

     These devices could also be used to isolate against radioactive contamination. In that role, docking against the SRV may not be feasible and tethering at a suitable separation distance may be required.

H. Exit from DV

     Much of what has already been discussed under transit and entry into the DV will, of course, also apply to the exit phase of the rescue mission. A PAL is as necessary to exit as to entry unless the rescue crew has been able to provide every member of the DV crew with a pressure garment, thus permitting the decompression of the DV compartment prior to exit. Pressure suits are also required if the vehicles are not docked. However, many medical situations can be postulated for a crew disabled by the emergency which may prevent dressing at least some of the DV crew in pressure suits.

     Broken arms and legs are examples of such situations. In such an instance, the concept of a transfer capsule might be valuable. Such a device would also be stowed in the collapsed condition within the SRV in order to reduce storage volume requirements.

     A capsule design concept for transferring men and equipment between the rescue vehicle and the DV is shown in Figure H-21. A North American Rockwell hatch design, featuring a hatch within a hatch, was selected as a representative design. The 5.0 ft (1.5 m) outer diameter hatch corresponds to the transfer tunnel diameter used in the space station design. The inner auxiliary hatch is approximately 3.0 ft (0.9 m) in diameter. This hatch is large enough to permit passage of a personnel carrier defined in Appendix G for transporting an injured astronaut. This inner hatch is also large enough for transporting emergency equipment into the crew transfer capsule. Modifying the North American Rockwell docking hatch to include a latch ring permits attaching the crew transfer capsule directly to the hatch, thus eliminating additional docking fixtures. This concept results in a smaller diameter attachment and reduced weight.

     The transfer capsule consists of two major components, an inflatable member and a cylindrical metal shell structure approximately 36.0 inches long attached to the inflatable member. The part of the shell structure that attaches to to the DV hatch latch ring is designed to incorporate a number of docking latches located radially around the shell. These docking latches engage the inside lip of the latch ring and achieve attachment to the hatch in a manner similar to that described for the attachable docking fixture. An inflatable pressure seal is provided between the capsule and the hatch. The cylindrical metal shell structure contains a removal hatch that is mounted approximately midway inside the shell. The hatch is removable in a manner similar to the Gemini heat shield hatch. The inflatable section is inflated to a shape similar to that shown in the sketch by pressurizing the capsule with breathing atmosphere provided from high pressure storage containers.

     In the stowed position, the inflatable portion of the capsule is folded and packed inside the metal shell portion of the capsule. The stowed volume and weight are estimated at 50 ft3 (1.4 m3) and 500 lb (227 kg).

     After the astronaut has been placed into the capsule, the hatches are resealed and the capsule is transported to the SRV by manipulators or by the rescue crew with AMUs. Attached to the SRV, the astronaut may be removed from the capsule or may be restricted to the capsule for a quarantine period, with life support provided from the SRV.

Rescue Vehicles

The Space rescue report says a comprehensive cis-Lunar rescue plan will need several vehicle types to cover all the emergency situations:

  • An orbit-to-orbit specially designed Space Rescue Vehicle (SRV)
  • A reusable surface-to-orbit space shuttle capable of carrying a fully loaded SRV in its cargo bay from surface-to-orbit and orbit-to-surface (perhaps with orbital propellant depots to refuel). It has limited rescue capacity, but only for DV in LEO.
  • A reusable nuclear orbit-to-orbit shuttle. This is the only means of transportation between LEO and either GEO or lunar orbits. It can deliver and return an SRV.
  • A space tug. This is a general purpose orbit spacecraft which can perform many of the functions of a SRV. While not optimized for rescue, there will be many already in orbit performing tasks. It may be quicker to dispatch a space tug rather than wait for a SRV to be ferried up into orbit. The tug probably has more delta-V than a SRV, unless the latter is fitted with a special propulsion stage.
  • Orbital Propellant Depots in LEO and lunar orbit
  • All space vehicles should have enough emergency delta-V for mid-course abort from in-transit trajectories to either geosynchronous or lunar orbit. This will make them easier to rescue.
  • All space vehicles should be equipped with emergency life support. This will give more time for a SRV to arrive.
  • All space vehicles should have an international standard universal docking port. Otherwise rescue is much more difficult if the rescue vehicle has incompatible ports.
  • A broad enough Terra based communication network to provide continuous coverage with a distressed spacecraft (DV) and SRV anywhere in cis-Lunar space. And provide radar tracking coverage for DV with damaged communications
  • Treaties to allow space shuttles or other rescue vehicles to land at international landing sites, in order to reduce required on-orbit loiter periods waiting for a national landing site to come into range. A mid-Pacific landing site is vital.
  • A dedicated launching pad and dedicated vehicle for emergency use only may be required to shorten ground-based reaction time. A reaction time of 1 day is acceptable but probably not possible. Ground delays can approach 150 hours. Ascent and rendezvous with a subsynchronous DV can take up to 26 hours. Ascent and rendezvous with a random target can take up to 38 hours.

American manned rescue spacecraft. Study 1970. Influenced by the stranded Skylab crew portrayed in the book and movie 'Marooned', NASA provided a crew rescue capability for the first time in its history.

Status: Study 1970. Gross mass: 16,800 kg (37,000 lb). Span: 3.90 m (12.70 ft).

A kit was developed to fit out an Apollo command module with a total of five crew couches. In the event a Skylab crew developed trouble with its Apollo CSM return craft, a rescue CSM would be prepared and launched to rendezvous with the station. It would dock with the spare second side docking port of the Skylab docking module.

During Skylab 3, one of the thruster quads of the Apollo service module developed leaks. When the same problem developed with a second quad, the possibility existed that the spacecraft would not be maneuverable. Preparation work began to fit out a rescue CSM, and astronauts Vance Brand and Don Lind began preparations to rescue astronauts Bean, Garriott, and Lousma aboard the station. However the problem was localized, workarounds were developed, and the first space rescue mission was not necessary. The Skylab 3 crew returned successfully in their own Apollo CSM at the end of their 59 day mission.

Crew Size: 5. Habitable Volume: 6.17 m3.

From Astronautix: APOLLO RESCUE CSM

The Boeing X-20 Dyna-Soar was created as a hypersonic nuclear bomber. After the invention of ICBMs the X-20 was obsolete before they had even started to bend metal. Desperate to salvage the project, they frantically tried to brainstorm alternate missions. One was a space rescue vehicle.

However no compelling use case could be found. The program was cancelled in 1963.

Payload mass delivered to LEOCost per payload kilogram
2.8 metric tons$11/kg (1968 dollars)
Gross Mass97,976 kg
Empty Mass6,668 kg
LEO Payload2,812 kg
Thrust (vac)1,558,100 N
464 s
Diameter6.6 m
Length18.8 m
Num Engines36

The Saturn Application Single-Stage-to-Orbit (SASSTO) is from Frontiers of Space by Philip Bono and Kenneth Gartland (1969)

It is relevant to our interest because it could easily be turned into a LEO rescue ship. Especially since it can land under its own power.

In 1966 when winged space shuttle designs were being studied, the Douglas Aircraft Company was doing a cost-benefit analysis. They were comparing reusable space shuttle costs to throwaway two-stage ballistic boosters. Somewhere along the line they took a look at whether it was possible to make a reusable single stage ballistic booster. The SASSTO was the result. The payload was not much, but it was enough for a Gemini space capsule. A Gemini would transform the SASSTO into a space taxi or even a space fighter, capable of satellite inspection missions. Without the Gemini it could deliver supplies and propellant to space stations and spacecraft in LEO.

Bono pointed out how inoperative satellites could become space hazards (although the concept of the Kessler Syndrome would not be created until 1978). A SASSTO could deal with such satellites in LEO (Bono called this Saturn Application Retrieval and Rescue Apparatus or SARRA). Even better, such satellites could be grabbed and brought back to Terra for refurbishment and re-launch. This would be much cheaper than building an entire new satellite from scratch, which would interest satellite corporations. Only satellites in LEO though, communication satellites in geostationary orbit would be out of reach.

The interesting part was on the base. Conventional spacecraft trying to do an aerobraking landing need a large convex heat shield on the base (for example the Apollo command module.). Unfortunately a reusable spacecraft has a large concave exhaust nozzle on the bottom, exactly the opposite of what you want. Tinsley's artist conception for the "Mars Snooper" had petals that would close over the exhaust nozzle sticking out of the heat shield, but that was impractical.

Douglas' solution was to use an aerospike engine with the spike truncated (which they confusingly call a "plug nozzle", contrary to modern terminology). The truncated part became the heat shield, the untruncated part around the edge was the aerospike engine.


This is from Space rescue operations. Volume 2: technical discussion and Space rescue operations. Volume 3: Appendices (1971)

This is a crewed spacecraft designed for a rescue mission, to save astronauts in a disabled spacecraft.

Warning: don't be confused. In the documents are references to an Earth Orbit Shuttle (EOS) and a Space Shuttle (SS). The EOS is what we would call a Space Shuttle, and the Space Shuttle is what we would call a Reusable Nuclear Shuttle.

In the documents, focus on the rescue vehicle called the EOS/MCCM, and ignore any references to the "Space Shuttle." I became mightily perplexed while reading the documents before I figured this out. EOS is "Earth Orbit Shuttle", a reusable heavy lift vehicle. CCM is "Crew/Cargo Module", a standard module sized to fit inside the EOS. They took the CCM design and modified it into an orbit-to-orbit rescue vehicle, a "Modified Crew/Cargo Module" or MCCM.

The space rescue vehicle relies upon the existence of an EOS capable of boosting the SRV into orbit and transporting it from orbit to the ground. This means the EOS has to have a cargo bay large enough to accommodate the SRV (which means when you are modifying a CCM into a SRV, don't make it too large to fit), and the EOS needs enough delta V for a loaded round trip (which may mean stationing orbital propellant depots in LEO for a quick re-fuel).

The Space Rescue Vehicle (SRV) is a standard EOS crew/cargo module (which in our time-line was never created) modified into a space vehicle. It is called the Modified Crew/Cargo Module or MCCM. Rescue specific features include:

  • Docking fixtures
  • Air lock
  • Manipulators
  • Special rescue equipment
  • Rescue trained crew

For low delta-V missions (60 m/s) it relies upon its RCS for propulsion, if more delta-V is needed a large propulsive module (PM) can be attached (LOX/LH2 fuel). It is not capable of reentry, it has to return to an orbital safe haven (space station or reentry vehicle). It can be based in orbit, or based on Terra and boosted into orbit by an EOS.

An MCCM boosted by an EOS has no propulsive module, if one is needed a second flight is need to boost it into orbit to be mated to the MCCM. The modules will probably be loosely based in the propulsion modues for the Boeing Space Tug. In the table below, different sizes of propulsive modules are shown with their different delta-V capabilities.

no PM
ΔV61 m/s305 m/s4,330 m/s5,490 m/s
Life Support4 days4 days4 days14 days
Crew and
Payload4,990 kg
PM dry mass0 kg358 kg5,200 kg7,400 kg
Propellant Mass187 kg1,000 kg31,500 kg51,700 kg
TOTAL13,600 kg15,000 kg50,300 kg72,600 kg

As mentioned before, the Space Rescue Vehicle is a EOS crew/cargo module modified into a spacecraft.

The foreword compartment is probably loosely based on the crew module for the Boeing Space Tug.

The center compartment is retrofitted with a sizable reaction control system (RCS). This can be the entirety of the spacecraft's propulsion system for missions with delta-V requirements under 60 meters per second. Otherwise a larger propulsion stage is mated to the "aft" end.

The aft cargo compartment is refitted to accommodate crew and passengers from the distressed vehicle, including incapacitated members transported by personnel carriers. The cargo section is also outfitted to allow medical aid to be provided, allowing the SRV to also act as an ambulance.

The structure is modified to accommodate special equipment appropriate for a rescue mission: portable airlocks, transfer capsules, manipulator arms, etc.

Since the SRV is based on an EOS crew/cargo module, it can be designed to fit into an EOS (NASA space shuttle) cargo bay. This will allow it to be boosted into orbit and recovered back to Terra's surface by an EOS. This allows the SRV to use off-the-shelf technology instead of the headache of designing some new technology from scratch.

The SRV has an estimated reaction time of one to two days, between the declaration of the emergency and the launch of the SRV. Estimated cost is $250 million US in research and development, and $70 million US per unit, in 1971 dollars (about $1.55 billion and $434 million US in 2019 dollars). Estimated service life of the SRV is 16 rescue missions.

It is possible to make an uncrewed version of the SRV, but of course the rescue will need more self-help on the part of the crew of the distressed vehicle. The SRV is required in rescues when the crew of the distressed vehicle are incapacitated or otherwise incapable of utilizing self-help.


(ed note: Cot-Vee = Cargo Orbital Transfer Vehicle {COTV}, Pot-Vee = Personnel Orbital Transfer Vehicle {POTV}, Eff-Mu = Extra Facility Maneuvering Unit {EFMU})

      There were few amenities on the Pot-Vee Edison. But since the transition to GEO Base took several hours, the craft did have a bathroom of sorts—nothing more than a simple adaptation of the proven technology of the SkyLab "waste management system," as the old NASA circumlocution labeled it. The Personnel Orbital Transfer Vehicle itself was just a double-decked cylindrical cabin section eighteen feet in diameter and fifty-five feet long with a control compartment, docking air lock, and tunnel forward. On its aft end was the cylindrical hydrogen-oxygen propulsion module, the common orbital propulsion module used for both Pot-Vees and Cot-Vees.

     "Easy flight today," Jackson remarked. "Three hours, fourteen minutes dock to dock. Relax and enjoy." (ed note: transit from LEO to GEO)
     "Pretty short time for such a high lift, isn't it?" Stan Meredith asked. "Planning on high boost?"
     "Naw! This flying sewer pipe is boost-limited to point-one-five gees because of its structure," Jackson explained. "Besides, we don't need the boost that's required for Earth-to-orbit. You'll hardly notice it now—but, man, it'll feel like a rock dropped on you after you've spent six weeks in weightlessness!"
     The Ancient Astronaut was right. There were some bangs, clanks, muffled clunks, and gentle jolts as the Edison undocked from LEO Base. And when the thrust of the oxygen-hydrogen rocket engines came on, there was the gentlest of accelerations, accompanied by a slight vibration and a damped shaking.
     "Combustion noise being transmitted through the thrust structure, plus a little bit of damped pogo oscillation," Fred Fitzsimmons explained.
     "Why didn't they get the pogo out of these ships before they put them into operation?" Dave Cabot asked. "Didn't pogo oscillations give the engineers all sorts of trouble on Saturn and the Space Shuttles?"
     Fred smiled. "Welcome to private-enterprise astronautics! There's worse vibrations in an airplane. It costs so much to get all pogo oscillations out of a design under all sorts of load conditions—and these Pot-Vees operate with all kinds of loads—that it's more cost-effective to let them shake . . . within reasonable limits, of course."
     "But won't this thing eventually shake apart?" A note of anxiety entered Dave's voice.
     "Nope," Fred replied. "Never had a Pot-Vee crumple yet. The engines are de-rated so much that the pogo doesn't affect them, and the engines themselves are modernized versions of very old, well-proven designs that never gave a bit of trouble."
     "RL-10s," Stan put in.
     There were no cabin windows in the Pot-Vee, so it was a three-hour flight without a view.

     Stan and Fred discovered that it took almost nineteen minutes just to get to Charlie Victor, Mod Four Seven. There were a lot of hatches to go through and a lot of modules to traverse. "Fred, if we don't find some faster way to move around this rabbit warren, a lot of people are going to be dead before we reach them," Stan pointed out, finally opening the hatch to Mod Four Seven.
     Fred was right behind him through the hatch. "I'll ask Doc to see Pratt about getting us an Eff-Mu."
     "What's that?"
     "Extra Facility Maneuvering Unit. A scooter to anybody but these acronym-happy engineers."

     "You want an Eff-Mu so you can get around GEO Base faster."
     "Right. We lost the hyperpyrexia case because we couldn't get there fast enough. It takes forever to go through all the hatches and corridors of GEO Base."
     "Stan, I agree on both counts," Tom replied. "You need an Eff-Mu, and all of us need to be able to get around GEO Base faster in emergencies. But do you think a standard two-man Eff-Mu will really do the job?"
     "Why not?"
     "Why don't Earth-bound paramedics use motorcycles?"
     "I see what you mean. We need room for the patient."
     "Roger. Eventually maybe not, but right now we've got to provide that, too. Is there any Eff-Mu type that'll handle the two of you plus a patient?"

Pratt called him. "Doc, your special ambulance is coming up in the next Cot-Vee supply ship. Should be docking in six hours at Portlock Foxtrot. We're also putting a docking collar module on the free end of your med module, so don't be disturbed when you hear noises. You'll be able to dock right to your sick bay."

(ed note: one hex module is a hexagonal prism, about 3.7 meters wall to wall (12 feet), 15.2 meters long (50 feet), and has a volume of 241 cubic meters (8,500 cubic feet)

     The Pumpkin turned out to be a masterpiece of quick-and-dirty engineering. It was half a hex module outfitted with a StarPacket vernier engine as its main propulsion system and a series of electric thrusters for maneuvering. It had no direct view to the outside universe, only an array of video displays—large windows in space were a constant trouble source because the state of the art couldn't keep them from leaking, and the Pumpkin's life-support consumables were limited to twenty-four man-hours with no recycling. The unit sported a universal docking collar on the end of the hex module opposite the StarPacket vernier engine.
     Tom went with Fred and Stan to take delivery of their new gadget and bring it around to the med module dock. Pratt's men had latched the half hex of a docking port and pressure lock to the med module a few hours earlier in an operation that took only twenty minutes. GEO Base had been designed like an Erector set with plug-in modules; there was no time to build pretty or permanent space facilities on this job.

     He looked over the panel. "Attitude indicator. Four relative velocity indicators linked to eight search radars and three lidars at will. Beacon transponders. You know, this really isn't that much different from flying airplanes on instruments."
     And it wasn't. They returned for their P-suits, loaded another twenty-four man-hours of oxygen aboard, then checked out the Pumpkin—propellant load, battery-charge level, life-support-system consumables level, and the rest of a three-page checklist that someone had managed to put together for the Pumpkin when it was assembled at LEO Base. The controls had been highly simplified and were like those of a helicopter, with two sidearm controllers and two foot pedals to provide control in roll, pitch, yaw, and translation in six degrees of freedom. The StarPacket vernier engine offered enough thrust to get the Pumpkin moving for fast sprints, while the electric thrusters—the same kind used to propel the SPS array modules from LEO Base—permitted the gentlest of velocity changes.

     The Pumpkin's saved a couple of people already. Three of us have learned how to operate it: Stan, Fred, and myself. Now I understand why space pilots are people who are instrument-rated airplane pilots and also own their own boats. "Flying" the Pumpkin is like flying an airplane by instruments; you must believe what those gauges are telling you, and you can't pay any attention to the inputs from your vestibular apparatus or from kinesthetic senses. Docking and undocking the Pumpkin is like bringing the S.S. Patrick Miller alongside and gently docking to a pier; the Pumpkin has far less momentum, however, and is probably more like docking a row boat. There isn't anything difficult about it provided you aren't in a hurry.
     That's going to be the biggest problem with the Pumpkin. When Fred and Stan are on a call, they're in a hurry. I expect to get reports of hard docks. I hope they don't crumple too much stuff until they learn how to handle the Pumpkin under the stress of an emergency. I'm not too worried about them crumpling the Pumpkin; all the stress is column loading on that hex module, and it'd take a big bump to make the structure fail in that mode.

     Together, they went through the power-up checklist. Total time, forty-two seconds. Less than three minutes after the call, Fred retracted the docking latches and backed the Pumpkin away from the med module on thruster power. While Fred was doing that, Tom interfaced the ship's computer with the one in GEO Base via radio link; he called up a three-dimensional display of the current GEO Base configuration and had the computer call out the location of the accident site.
     "Computer has fed course parameters to the guidance system," Tom reported. Fred slued the ship and coupled the autopilot.
     "Roger! Autopilot locked on. Stand by for thrust."
     Tom spoke over the radio. "Traffic, Pumpkin. Emergency. Departing med module under primary thrust for Array Subassembly Module One Zero Seven. Are we clear to boost?"
     Fred held his finger over the abort switch in anticipation of a possible Traffic delay. But it didn't come. "Pumpkin, Traffic. Clear to boost."
     The boost came with a little fishtailing. "Dammit!" Fred swore. "Doc, this autopilot doesn't warm up fast enough. We'll have to go manual follow-up."
     "I'll take it, Fred." Flying the Pumpkin wasn't as hard as flying a light airplane on instruments through an overcast at night. In this case, with the course already plotted by the computer, all Tom had to do was keep the marker bugs centered on the attitude-situation and relative-velocity displays. With the sidearm controller in one hand and the thruster and vernier throttles in the other, Tom didn't let the red Xs of the marker bugs deviate from the center of the display.
     They picked up the group of P-suited figures on video long before the computer called for retros. To keep the thruster and vernier discharges away from the P-suited workers, Tom slued the Pumpkin in yaw and applied retro thrust by vector.

     The paramedic didn't say anything, but reached over and activated Tom's P-suit backpack. Tom did the same for Fred. Only then did they disconnect from the Pumpkin's life-support system.
     "Dump pressure, Fred."
     Tom felt his suit pressurise as the atmosphere of the Pumpkin was dumped into space through spill valves that equalized the thrust produced. Normal procedure wouldn't have permitted dumping of pressure, nitrogen being the one gas that had to be brought up from Earth. In addition, the venting created a gas halo around the ship that might have permitted arcing of electrical equipment on the SPS array. But in an emergency where the Pumpkin had to be depressurized rapidly, there was no alternative.

      “Med, emergency in progress. Please stand by for possible rescue attempt. Better stand by with Pumpkin Array Subassembly Module Two Zero Two’s on its way up from LEO Base. They’ve had an accident. The survivors are in the personnel module, with the life-support system out and only a UHF emergency locator transmitter with limited voice capability.”
     “How many casualties?” Torn asked.
     “The brief report said three dead—one on EVA, the other two in the control module when it dumped to vacuum. The remaining four are apparently alive and uninjured in the personnel module, but they have life-support air for only an estimated seven hours.”
     Tom turned to Fred Fitzsinnnons. “Stumpy, power-up the Pumpkin and be ready to go. I don’t know where the subassembly is or whether we can reach. it with the Pumpkin. I’m going to Central. Dorothy, get things ready here for hypoxia therapy and possible abaryia resuscitation.”

     Tom located Herb Pratt surrounded by a bank of readouts and panels at Central’s main overview consoles. “We’ve got Doc Noels here now,” Pratt addressed the other three images on the screens. “Doc, are your people standing by to handle whatever medical problems might arise from this?”
     “We’re always ready for whatever crisis arises,” Tom replied curtly. “Can you tell me what’s going on, please? You’ve got a problem? Where are the Edison and the Steinmetz? Can’t those Pot-Vees rendezvous?”
     “Doc, if you’ll listen, you’ll discover what our problems are,” Pratt told him with uncharacteristic tact, either because he had really come to respect the GEO Base doctor or because the Hawk was on the conference net.

     “Array Subassembly Module Two Zero Two left LEO Base on schedule,” Pratt forged ahead. “According to its trajectory, the electric thrusters would boost it to GEO Base in seventeen-point-two hours. The normal crew of seven was aboard—two guidance-and-control technicians, two electric-thruster mechanics, two power-bus controllers, and the array commander. At fourteen-twenty-one, Zulu time, one of the electric-thruster mechanics, Bob Henson, got into his P-suit, cycled through the transfer lock, and powered-up the Eff-Mu to go out and check Thrusters Five and Eleven on the far dorsal surface of the array. Both thrusters were acting intermittently. There was no telemetry on the Elf-Mu, so we don’t know what happened when Henson started to move out along the array. Maybe a thruster valve stuck—we’ll never know. But he put the Eff-Mu right through the side of the pressurized control module.
     “The pressure in the control module dumped immediately,” Pratt continued soberly, “killing Lem Udevitz, the subassembly commander, and Sally Renquist, a control tech: As a matter of fact, they were blown out through the hole in the module wall. The presence of that much gas in the vicinity of the array, plus the presence of the Eff-Mu, which may also have dumped to vacuum and added to the out-gassing, caused the main array bus-bar junctions near the control module to arc. You don’t short out a nineteen-megawatt array subassembly without fun and games. All the protective circuits activated. The bus bars acted like massive fuse links and vaporized. We don’t know what happened to Henson and the Eff-Mu, but our radar signature says the Eff-Mu isn’t anywhere around the subassembly now. It may have been vaporized in the arc-over, or it may be tumbling out of control with all circuits dead somewhere between here and LEO Base.”
     Pratt checked two computer display readouts. “They lost most of the pressure in the living module before somebody slapped something over the holes and sealed them. Three of the survivors suffered the bends from the rapid decompression. Fortunately, one of the power-bus controllers was in her P-suit and was able to act quickly enough to save most of the life-support consumable gases for the module.
     “At this point, four of them are still alive in P-suits in the living module with emergency battery power for illumination. They’ve got their P-suits plugged into the emergency life-support fittings, and they’re trying to scavenge as much of the life-support consumables as possible. The power-bus controller found the emergency locator transmitter (ELT), got it on the air, and transmitted the basic elements of this report. Then she shut down the voice-transmission capability to conserve battery power. We’re still picking up the locator signal.”
     Pratt looked around at the three screens and concluded, “Here’s the problem: They’ve got … uh … seven-point-eight hours of life-support consumables left, according to calculations based on information received in the brief ELT report. The Edison is one-point-three hours from docking at LEO Base; no way for Nat Wallace to turn it around and head for the accident scene. He’s running heavy. He’ll have to be refueled, and that will take at least two hours after he docks. There’s no way he can make it to Two Zero Two before they run out of air.
     “The Steinmetz is two-point-nine hours from docking at GEO Base, and Ross Jackson’s running loaded with enough delta-v plus standard reserves to make GEO Base rendezvous, period. There’s no way he can reshape orbit to get to Two Zero Two in time, and when he got there he couldn’t do anything because he has only enough life-support for his passenger manifest, plus normal reserves. He wouldn’t have the delta-v capability to get to either LEO Base or GEO Base afterward. We’d just have a Pot-Vee and fifty more people stranded along with the subassembly.”
     Pratt looked around again. “That’s it in a nutshell, confirmed as best we can by radar track and signature analysis from here. We’re rechecking as many permutations and combinations as possible with computer runs, looking for some trajectory that would let us rendezvous a Pot-Vee with Two Zero Two, but we haven’t found it yet.

     “One guidance-and-control tech, Pat Mulligan. One electric-thruster mechanic, Jim Service,” Charlie Day announced from LEO Base as he checked his departure manifests. “And two power-bus controllers, Ed Swenson and Lucky Hertzog—Lucky was the one in the P-suit when the accident happened, and she was the one who sent the report.”
     Lucky? In that accident? With less than eight hours of life-support left? And no way to get to them with the Pot-Vees? Tom swallowed and tried to think straight. Given the situation, what could be done? What could he do?
     Finally, Owen Hocksmith broke the brief silence. “Four people and damned little time. Anybody got any ideas? To hell with the schedule, and to hell with the rules! Somehow, we’ve got to make an effort to get to them. No, we’ve got to get to them and bring them out of this alive!”

     There was silence from everyone on the conference net.
     “Dammit!” Hocksmith exploded. “We move thousands of tons of cargo and hundreds of people around in orbit every day! Surely there’s some way we can get to four people in a transfer orbit within seven hours and with enough lifesupport to keep them alive, even if it’s for just long enough to get a Pot-Vee turned around and on its way.”
     Dan Hills spoke up earnestly. “Let’s think about that one. We don’t have to get them and get back. We just have to get to them within seven hours with enough oxygen to sustain them until we can get a Pot-Vee there. Charlie, Herb, what do you have up there that one man can boost and control, carry about fifty man-hours of Oh-two (10 hours of oxygen for 1 rescue pilot and 4 survivors), no guidance system, vectors being fed to the pilot verbally from analysis of the radar track?”
     “I haven’t got an Eff-Mu big enough,” Charlie Day replied. “How about it, Herb? You’ve got Eff-Mus that are bigger. Do any of them have the delta-v to reach Two Zero Two in time with a pilot and fifty man-hours of Oh-two?”
     “Hold on, let me get a readout on the delta-v required for a seven-hour rendezvous.”

     Tom moved to another keypad and display. He had an idea. He didn’t know if it would work or not. He couldn’t do the math, and he couldn’t program the computer. But he had access to a very large general-purpose computer net: GALEN. He didn’t know if GALEN could handle celestial mechanics, but he could certainly ask.
     It could, using its links through EuroMed to computers in Brussels and London, plus a link into a DOD computer net through Bethesda Naval Hospital. He asked GALEN and its peripheral systems to solve the problem for him. GALEN already had all the parameters on the Pumpkin. All Tom had to do was feed it numbers on the location and trajectory of Two Zero Two and the location and orbit of GEO Base.
     When he was through, he had the answer.

     Dan Hills and Herb Pratt didn’t. “Mr. Hocksmith, the mission’s beyond the delta-v capabilities of any of our Eff-Mu vehicles,” Dan Hills announced. “They were designed as short-range craft for getting around the SPS during construction. They don’t have very much delta-v as a result.”
     “You’re the most negative problem solvers I’ve ever seen!” Hocksmith snapped back. “Four people out there, and we can’t come up with a way to get to them in time? Do you know what this could mean, gentlemen? It could mean that we get shut down for killing too many people. The hue and cry of the press could trigger the politicians and bureaucrats to do something, anything, to stop what they consider to be slaughter. We’re already in that position, as you damned well know. We’re supposed to be the world’s brightest people when it comes to space transportation. We’ve built and operated the biggest space transportation system in history. And we can damned well figure out some way to make it work to save four people! Think!

     Tom tapped Pratt on the shoulder and motioned for him to move over so he could get in the pickup’s field. The action came as such a surprise to Pratt that he moved immediately without a word. “Smitty, I’ve got an answer,” he told his old friend. “The Pumpkin, the GEO Base ambulance you designed for us, Smitty, It’s got more delta-v than any Eff-Mu because we need to move around fast here, which means high-g and gobs of thrust—in comparison, that is. It’s normally rated for a thousand pounds of payload. I’ve just been working with the GALEN computer, and I asked it whether or not I could get there as a single pilot in a P-suit with a cargo of five fifty-cubic-foot Oh-two backpack bottles. That’s about a hundred fifty pounds, plus me in a P-suit at two hundred pounds. Just to be on the safe side, I figured five hundred pounds; I may need some medical gear because three of those people are in severe pain with the bends. I can get there with the Pumpkin and enough Oh-two to save them. But I can’t get back. You’ll have to come rescue me with the Edison or the Steinmetz. That’ll give you ten hours after I make rendezvous. I can do it! Can you get to me in seventeen hours?
     “I won’t let you go,” was the comment from Hocksmith.
     “I won’t let Stan or Fred go. I’m a doctor, and those people may need a doctor, not a paramedic,” Tom explained.
     “We can get to you,” Pratt put in, looking at the display screen linked to GEO Base computer. “It’ll be close, but we’ll get there. Better take a couple of spare bottles, Doc, just in case.”
     “Can’t. I’ll be rendezvousing with electric thrusters as it is. Barely enough propellant to get me started and almost stopped. When it’s that critical, I want about five-percent reserve. Just get there within ten hours after I do, Herb.”
     Charlie Day broke in. “We’ll start from this end with the Edison, too. We’ll come after you from LEO and GEO. This operation’s got to have some redundancy built in somewhere!
     “Okay, I’ll be depending on both of you after I get to Two Zero Two,” Tom said. “I’ll fly by vectors from GEO Base radars and lidars. Herb, have your gang track me and give me those vectors. You’ll have my position, my trajectory, and your computer power—in short, all the data you’ll need. All I need is communication with you. No other way to do it.”
     “You’re right,” Herb remarked.
     “Tom, forget it! You’re not going!” Hocksmith yelled.
     “Smitty, you forget it! And shut up! You’re sitting on your ass down there with gravity and an atmosphere around you. Don’t try to run this operation by long distance. Herb, Charlie, and Dan work for you as employees—they’ve got to follow your orders. But I’m one of your contractors, and the Pumpkin was bailed to me by Eden Corporation. So you can’t tell me what to do at all! Or do you want four people to die?”
     Hocksmith threw up his hands. “Goddammit, go get’em, T.K.! But please be careful!”
     “A martyr I’m not,” Tom replied flatly. “Let’s go, Herb. Time’s a-wasting!”

     Tom was a little under his mass estimate. He did take a few extra backpack bottles and the equivalent of a spare fan belt. “I want a hand-portable communicator or a booster amplifier on my backpack radio, Herb. I will have to go EVA to get aboard Two Zero Two, and I want to be able to talk to you if necessary. I also want the unit as an ELT if something happens.”
     ;“We’ll give you a little extra delta-v, Tom,” Pratt told him. “I’ll have three of our Eff-Mus couple to you during GEO Base departure boost and supplement your own thruster on the Pumpkin. They’ll undock after they’ve boosted you. Sort of a two-stage vehicle. Computer says that’ll give you a ten-percent reserve—slim, but a hundred-percent improvement on the five-percent reserve you thought you’d need.”
     “Still going to be close, but thanks for the additional help,” Tom said as Fred buddy-checked the P-suit connections.

     The undocking was very gentle. Tom was reluctant to use any delta-v he didn’t have to. As he backed away from the med module’s docking. port, he saw on his displays that three Eff-Mus had drawn alongside. Into his helmet speaker came the voice of one of the Eff-Mu drivers. “Pumpkin, Eff-Mu Fourteen. We’re ready to move in and couple. Don’t try to hold position; let us move on you.”
     “Roger, Eff-Mu. GEO Base, Pumpkin, radio check.”
     “Loud and clear, Pumpkin. How me?”
     “Five by. While the Eff-Mus are coupling up, let’s check the data links.”
     “Go ahead, Pumpkin.”
     Tom exercised his small on-board computer, testing its megabyte memory (hah. Nowadays people have thousands of times more RAM in their smartphones. Not radiation-rated, though) and squirting the test data on the up-link to GEO Base, where the GEO computer examined it, determined it was all there, and echoed it back to the Pumpkin accompanied by its own test data. Within three seconds, the two computers were happy with each other and in communication.
     “Pumpkin, GEO Base,” Pratt’s voice called. “The Eff-Mus will maneuver you into boost attitude. We’re working this mission with Earth-oriented references, equatorial category.”
     Tom informed his computer and control systems. “Okay, Geo Base. Pumpkin’s ready for attitude positioning.”
     The three Eff-Mus gently lined up the Pumpkin.
     “Close enough,” Herb told Tom. “Your down-link data matches. Computer’s grinding out the final trajectory elements. Stand by for real-time updates on the up-link.”
     When the Pumpkin boosted from GEO Base on its errand of mercy, the computer estimated that Two Zero Two had six-point-nine hours of life-support available. The estimated trajectory time was six-point-eight hours.
     “I don’t like those numbers, Herb. Too many chances for error, and I know this is only a quarter-percent data.
     “No, we’ve got very accurate info on Two Zero Two. Air Force is feeding us their SpaceTrak data, too, and it cross-checks.”
     “Okay, Eff-Mus have separated,” Tom reported, “and I’m getting a solid up-link data signal. I’m on manual control.”

     When Tom had taken flight training from Dick Callins at the Roswell airport years before, he never thought he would find that detestable simulated-instrument hood training useful in flying a spacecraft. But that was exactly what he was doing. Instrument flight training had taught him to ignore the inputs from his otoliths and his kinesthetic senses, to give up flying by the seat of his pants. Then, as now, he was forced to rely only on the data that was presented to him by instruments. And it required the same degree of control precision—only the data presentation was slightly different.
     He still had a gyro attitude indicator and a gyro vector indicator. Otherwise, the instruments were fully electronic.
     It was a simple task for computers. Radar and lidar from LEO Base, GEO Base, and the Earth’s surface tracked the Great Pumpkin’s beacon, providing the computers with direction, range, and Doppler relative velocity. The computers were also receiving tracking data from the ELT beacon in Two Zero Two; they knew where it was—and where it was going to be. The instructions for right-left, up-down, and fast-slow were transmitted to the Pumpkin on the data up-link, where the ship’s computer converted the data for display, telling Tom how and how much to change direction or thrust. The Pumpkin's simple autopilot couldn’t be used on this long flight because neither it nor the Pumpkin’s inertial guidance system had the accuracy required. They didn’t have to be accurate for operating around GEO Base and the SPS assembly; they just had to keep general track of where the Pumpkin was. Thus, Tom had to fly the Pumpkin by hand, keeping dots of light centered on displays and making sure that the indicators on graphic displays stayed right on the lines.
     It wasn’t difficult, because nothing happened very fast as long as Tom kept on top of things constantly.

     “Going right down the tunnel, Pumpkin,” Pratt told him.
     “Any further messages from Two Zero Two, Herb?”
     “Nothing but the beacon signal,” the base boss reported. “Its code hasn’t changed and indicates the situation’s the same.”
     “Any way to get word to them that we’re coming?”
     “They have no receiver, and they’re sealed in that living module, so there’s no way to send even a laser signal to them.”
     “That’s got to be grim,” Tom observed.

     The Pumpkin was coming up on final trajectory velocity. Tom concentrated on the displays, his hand on the main throttle with the Vernier throttles just below. He was also receiving a verbal countdown from Pratt. Five feet per second short of final velocity, he chopped the main engine and used the verniers to bring the Pumpkin to precisely the required velocity.
     “Looks good, Pumpkin. Right down the pike. Take five, because we won’t do a mid-course correction for two hours yet. I want to let the trajectory errors build until we’ve got a reliable track that we can correct with greater precision. No sense burning up vernier delta-v by correcting every little glitch in the radar track.

     Tom couldn’t help but think of Lucky Hertzog, trapped in that can, knowing how much oxygen was remaining but not knowing whether anybody was on the way, and not being able to find out. He agonized because he knew it must be hell. On the other hand, he didn’t think Lucky would come apart under the circumstances. She was made of stout stuff. He knew there would be no hysteria, only tight-jawed discipline right to the very end if necessary.

     “Pumpkin, GEO Base. Here’s your latest ETA at Two Zero Two.” Herb’s voice returned him to reality. “It’s tight, Tom. The estimate’s converged with the flight time. We show a rendezvous only five minutes before life-support exhaustion. I think it’s too close to call. Let’s hope Two Zero Two has instituted drastic conservation measures. If they have, you’ll make it.”
     “I refuse to trust any computer when it comes to that close a call on the chances of living or dying,” Tom snapped back. “I’ll make it, Herb, because we’re dealing with people, not with computers.”
     He hoped he was right.

     Tom saw it on the forward screen through a ghostly haze of electric-thruster plasma. The huge solar array gleamed in the sunlight and bright specular reflections overloaded the video pickup, causing streaks of overexcited display phosphor to paint wiggly lines on the tube face. He fired the vernier thrusters carefully to rendezvous as precisely as possible with the personnel module that appeared only as a tiny polygon on the near end.
     According to the digital readout, he didn’t have a foot-second of delta-v to spare.
     The computer also told him he was running out of time.
     He’d have to move in on the personnel module with one single continuous application of the thruster in order to save time. Then he’d have to do a fast EVA.
     He had prepared for that. During the hours of coast-in, he’d pumped the Pumpkin’s cabin atmosphere back into the ship’s life-support system and carefully blown-down the cabin to vacuum; in fact, he had used the blow-down to provide some fractional delta-v, which gave him a trifle more reserve. He’d even opened the hatch to vacuum. When he got to Two Zero Two, he was ready to move—fast.

     Suddenly his instruments began reporting relative velocity between the Pumpkin and Two Zero Two. The computer was presenting projections and forecasts of future velocities, positions, and closing rates. He knew he would have to be exceptionally precise and that he had only one chance. He realized that this was the, same degree of precision he had to exercise as a surgeon, and, as in surgery, he had only one opportunity to succeed.
     “Gently! Positive pitch! Too much, back it off! Bang yaw right a couple of times. Coming right on in.” Tom talked to himself as he often did during an operation or during instrument approaches in his Maule. “GEO Base, Pumpkin! Closing nicely. I’m videotaping the monitors, but I’ll give you a verbal — There’s a big hole in the side of the command module and a series of smaller holes in the personnel module. The ones in the personnel module look as if they’ve been sealed from the inside. There’re no lights showing. I’m receiving only the modulated r-f signal from the ELT. Okay, closing slowly … Ten feet and dead in space. I’m holding it there. I don’t want to bump the personnel module because I don’t know what internal damage it’s suffered, and it could collapse if I whanged it. How’s my timing?”
     “Tom, it’s too close to call,” Pratt admitted.
     “Okay, I’m uncoupling, going to backpack. My transmission may get garbled because I’m switching to the booster transmitter strapped to the backpack. Now I’m free. Moving to the hatch, hauling the backpack bottles with me. Out of the hatch. What a mess! Everything seems to be covered with a grayish deposit. Probably vapor deposition caused by the arc-over. The survivors are lucky. The reflectance of that coating is probably just enough to maintain a comfortable interior temperature in the personnel module.”

     Tom pushed off the five feet across the void to the damaged module, not even taking the time to latch a safety line. He hit with both feet and bounced back in spite of the fact that he had used his knees to absorb his momentum. He would have bounded right back to the Pumpkin’s hatch except for the two-hundred-pound bag of backpack oxygen bottles in his left hand. Its momentum forced him around as it kept going and thudded into the module. He planted his feet on the module again, looked for. handholds, found them, and pulled himself to the hatch.
     He banged on the closed hatch and could feel the vibrations through the soles of his P-suit boots. There was no response.
     “Dammit, I’m too late!”
     He tried to twist the latch, but couldn’t do it. He had to hold on to the bag of oxygen bottles with his left hand and, therefore, could work only with his right. His body twisted instead. So he banged again, hoping he might somehow dislodge the hatch-closure dogs or that someone might detect his banging and open from inside.
     “Open up! For God’s sake, open up!” He found himself screaming in his helmet that was pressed against the hatch. Maybe his voice would penetrate by direct contact.
     He almost fell into the module when the hatch suddenly swung open.
     And he found himself faceplate to faceplate with Lucky. She touched helmets, and he heard her say, “Well, you took long enough to get here, but did you have to make such a racket?” She reached out, put her arms around the neck of his P-suit, and hauled him into the module.
     And she continued to hold him tight.

From SPACE DOCTOR by Lee Correy (G. Harry Stine) 1981

This is from Design Concept for a Minimal Volume Spacecraft to Serve as a Mars Ascent Vehicle Cabin and Other Alternative Pressurized Vehicle Cabins by Robert L. Howard, Jr. (2016)

The design problem was to make the habitat module for a Mars Ascent vehicle (MAV), with enough life support to keep four astronauts alive from 3 to 5 days (20 person-days). There would have to be acceleration couches capable of protecting the astronauts from the acceleration stress of a Mars lift-off. It will need facilities for crew sleep, waste and hygiene, a galley, and meaningful crew work. BUT ABOVE ALL IT HAS TO BE AS TINY AND AS LOW MASS AS POSSIBLE. Because every gram counts.

It will be a Minimal Volume Spacecraft Cabin, or MVSC.

What is relevant to our interests is the fact that if you attach a propulsion module to this little honey, it becames an instant ambulance, with room for a pilot and emergency medical technician.

The configuration evolved from placing four almost prone astronauts in a 2 × 2 matrix, inside a horizontal cylinder just big enough to hold them, with hemispherical end-caps. The module turned out to be about 1.85 meters (73 inches) in diameter, and 3.4 meters (134 inches) long.

The MVSC has dual docking ports, one in the front and one in the rear of the cabin. These contain one meter square hatches framing a NASA Active-Active Mating Adaptor, though you could swap these for other docking adaptors depending upon what becomes the standard. Between the hatch and the maramon flange are utility connectors. So once docked the MVSC is connected to the other vessel's power supply and data net. Sort of like pluging in a USB cable. The two docking ports are identical so either can be used.

The crew seats are supported by one or more vertical struts positioned between the port and starboard set of seats. The seats can fold shut when not in use to make more free space. The seats can also be rotated to face the opposite direction.

Each seat has a computer display and controls. This study didn't go in to depth on what controls would be added, but they figure each seat will have a control-set containing:

  • Single edge key display (I guess this means an flat-screen display with a row of dedicated buttons along one edge)
  • Cursor countrol device mounted on the arm-rest (captive mouse or track-ball)
  • Deployable keyboard
  • Rotational Hand Controller (to maneuver the MSC with attitude jets)

There will also be an "auxiliary interface port" (i.e., a USB port) so you can jack in peripheral devices, like a flash drive or something. The controls are part of the seat, so they too can be rotated to face the opposite direction.

Immediately behind the seats is the cargo section. It is designed to accommodate the minimum of consumables, plus 250 kg of Mars surface samples. The cargo section holds two rows of Cargo Transfer Bags (CTBs) which span the width of the cabin.

In front of the seats is an open volume which partially allows the front hatch to swing open. The seats will have to be collapsed to allow the hatch full swing. If the seats are rotated to face the other way, the CTBs will have to be relocated to the new rear section.

The hab module subsystems are distributed along the module exterior, and inside the pressure vessel along the contours of the inner cabin walls. The Environmental Control And Life Support System (ECLSS) ducting provides fresh air at the crew head positions, and also provides umbilical connections to flight suits.

The report does not go into details but I'm sure the facilities for waste disposal and hygeine are Spartan. Probably more or less the same as on the Apollo lunar missions. Plastic bags for urine and feces, moist towelettes for your hands, and the rest of your body will just have to stew in its own juices until you dock with the mothership. Yuck.

The MVSC has many other uses besides being the habitat module for the MAV. The thing is inherently modular, just like the JPL Modular Hab System

Slap on a Reaction Control System (RCS) and you have instant space taxi (the report calls it a "crew transfer cabin"). They note that (with one exception) there has not been a case where two large complex spacecraft have docked. It is always some tiny capsule docking with a large complex spacecraft. Docking two big spacecraft is probably very risky.

A space taxi would be far safer, which is an argument to develop the MVSC. Without 20 person-days of consumbables you could squeeze six astronauts into the MVSC, for a trip that takes half an hour or so. By the same token, with only two astronauts, some of the consumables could be replaced with a real space toilet and a galley, for longer duration missions.

Yes, the proposed NASA MMSEV could also be utiized as a space taxi, but that is over-kill. A MVSC with an RCS sled is far cheaper.

Obviously adding some remote manipulator arms would turn the MVSC into a space pod, and a real rocket engine would make it into a space tug. But now you are actually stepping on the MMSEV's toes. Keep in mind that any rocket engine will mounted "below" the hab module, not over one of the docking ports. This is the same place it will be mounted in a Mars Ascent Vehicle, and will ensure that the direction of "down" will line up with the support provided by the seats.

A MVSC with a rocket engine and two crew could be modified to be a Crew Rescue Vehicle, basically a space ambulance. One crew is the pilot, the other is the medical caregiver. Part of the internal space would be repurposed into a medical treatment area for one incapacitated crew member.

A MVSC with most of the interior fittings removed could be used as a docking tunnel. This would be useful for space stations as well as surface bases. The tunnel is larger than you need for a just a simple pass-through, so it could also be used for stowage, subsystem equipment, or crew workstations. The external hull will also provide additional surface area to site solar arrays, heat radiators, and other whatnot.

Space pods can be used to repair satellites and other orbital facilities. The trouble is that the repairs can take several days and the pods do not have the life support for that. A MVSC can be modified to be a sort of life support depot with docking port for up to two space pods. Different sets of repair tools and replacement parts can be stored and swapped out as needed. Repair crew can dock to the MVSC to get some sleep and recharge their space pod ECLSS. The MVSC seats would be removed, a galley and real toilets added, and maybe even have some polyethylene bricks layered on the hull to turn the MVSC into a storm cellar.

And I'm sure it has occured to you that adding a high-thrust propulsion system and lots of weapons will transform the MVSC into a space fighter. Though this is more the MVSC being a convenient small habitat module for a weapons platform.


With the advent of lunar exploration and round trip lunar transport, both chemical and nuclear, there inevitably will arise malfunctions and emergencies. There will arise communication difficulties, navigational errors, propulsion breakdowns, and structural failures. There are possibilities of collisions between spacecraft and of fatal damage from matter in space. More likely, however, are onboard concerns of life-support malfunctions, auxiliary power irregularities, compartment over pressurization (in some cases, explosions), cargo shifting, and unforeseen disorders. These are the realities of increased space travel.

In anticipation of spaceflight realities, there would be need for a nuclear rescue ship operating in translunar space. The primary role of such a ship would be to save human life and those extraterrestrial specimens aboard any ill-fated lunar vehicle. A secondary role would be to salvage the spacecraft if at all possible.

This means that the rescue ship would require propulsive capability to drastically change orbit planes and altitudes. It would require excess ΔV to proceed with dispatch to rendezvous with a disabled spacecraft. In addition, capability would be required for transferring personnel and equipment, making repairs to a disabled vehicle, and even taking it in tow if conditions warranted. The latest advances in crew facilitation, passenger accommodations, repair shops, navigational devices, and communication equipment would be required. As an introductory concept, one arrangement of a nuclear rescue ship is presented in Figure 11-11 (see above).

A particular feature to note in Figure 11-11 is the use of two nuclear engines. Each engine would be of the lunar ferry vintage and, therefore, would be sufficiently well developed and man-rated for rescue ship design. These engines would be indexed by a nominal Isp of 1000 seconds; they would have a short time overrating of, perhaps 1100 seconds. This overrating implies conditional melting of nuclear fuel in the reactor for emergency maneuvers and dispatch.

A rescue ship would be characterized by a large inert weight compared to a regular transport vehicle. This means that large magnitudes of engine thrust would be required. However, during periods of non-emergencies, low thrusts could be used. The vehicle F/Wo characteristics (Thrust-to-weight ratio) would vary over a wide range: possibly from 0.1 during non-emergencies to 1 during emergencies. Two engines would provide the high thrust capacity for emergencies. During non-emergencies, one engine could be left idling; the other engine could provide low thrust for economic cruise. Furthermore, two engines would provide engine-out capability for take-home in the event of malfunction in one of the engines. For reactor control reasons, the two reactors would have to be neutronically isolated from each other. For this purpose, note the neutron isolation shield in Figure 11-11.

(ed note: Nuclear reactors are throttled by carefully controlling the amount of available neutrons within the reactor. A second reactor randomly spraying extra neutrons into the first reactor is therefore a Bad Thing. "Neutronically isolated" is a fancy way of saying "preventing uninvited neutrons from crashing the party." Related term is "Neutronic Decoupling")

A suggested patrol region for the rescue ship is indicated in Figure 11-12 (see above). Note that a rendezvous orbit has been designated so that the rescue ship could replenish its propellant from the nuclear lunar transport system. By having rendezvous missions with nuclear ferry routes, rescued personnel, lunar specimens, and damaged spacecraft parts could be returned to Earth without the need for the rescue ship returning. Also, rescue ship crew members could be duty-rotated this way. This would increase the on-station time of a nuclear rescue ship.

From NUCLEAR SPACE PROPULSION by Holmes F. Crouch (1965)

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