Atomic Rockets

Introduction

NASA learned early on that the decompression problems of soft space suits could be avoided if hard-shelled full pressure suits were used. If a soft suit was full pressurized, the astronaut would be splayed out like a starfish and probably could not bend their arms or legs. A hard suit does not have that problem, but instead has the problem of wearing out the astronaut. They are about as easy to work in as a set of medieval plate armor constructed of pure osmium. So NASA looked into adding a powered exoskeleton to the suit, to reduce the muscle strain on the astronaut. NASA eventually decided it was not worth the effort, but the idea just wouldn't go away. Especially if the powered exoskeleton is attached to a suit of armor. It would be "powered armor".

And it took about five minutes for science fiction writers to figure out if you put weapons on on the armor you'd have an unstoppable one-man-army suit that would let a 99 pound weakling beat the snot out of Superman.

Definitions

The Operator is the entity operating the man amplifier, either a person or a computer running either simplistic pre-programmed task software or full-fledged AI software. If the operator is a computer, the man amplifier is classified as a robot.


The Controls are how the operator issues commands to the man amplifier.

A Game Gontroller is a set of joysticks and a keyboard, or something along those lines.

An exoskeleton motion capture system (exo-mocap) is something attached to various portions of the operator's body to measure body motions, such as waldo hands, power gloves, or even a full-body frame. An exo-mocap for human form fitting man amplifiers sometimes use negative feedback. Exo-mocap for huge man amplifiers or remote controlled drones sometimes use haptic feedback. This means the operator is suspended inside the exoskeleton, and the exoskeleton is forced to conform to the current position of the remote drone. This allows the operator to do things like climb stairs and feel when the drone has walked into a brick wall.

A Brain–computer interface (BCI) uses electronics to directly communicate with the human brain in order to issue commands to the man amplifier. Sometimes the man amplifier can communicate back, with sensory information or with enslaving thought control. Also known as mind-machine interface (MMI), brain–machine interface (BMI), or direct neural interface.

In the movie Pacific Rim, the Humongous Mecha each have not one, but two pilots who do synchronised piloting. This seemed like a pretty stupid idea to me, until I read this report. Apparently with a BCI, a single pilot has an accuracy of 67%, but dual pilots have an accuracy of 90%. Reaction times are halved. And momentary lapses of attention are not quite as fatal, since the other pilot is hopefully still on the job. The technical term is "collaborative BCI".

Sometimes the man amplifier also has "computerized reflexes", to automatically react common situations, e.g., tripping over an obstacle or unexpectedly coming under sniper fire.


A Powered-exoskeleton is a human shaped external skeleton constructed of strong materials, with powerful electronic servomotors or hydraulic actuators replacing human muscles.

Definition: Man Amplifier

Man Amplifier: A more or less human sized powered-exoskeleton controlled by an internal exo-mocap with a human operator. In some cases the powered-exoskeleton and the exo-mocap are merged into a single unit. Generally the exo-mocap uses negative feadback. It is called a "man amplifier" because it literally amplifies the person's strength.

Definition: Prosthesis

Prosthesis: In this context, a Man Amplifier whose main purpose it to allow disabled persons to use their arms and/or legs.

Definition: Powered Armor

Powered Armor: An armor-plated Man Amplifier, generally with assorted integral weapons and battlefield sensors. May have a supplemental BCI.

Definition: Mecha

Mecha: A larger than human sized powered-exoskeleton controlled by a human operator in an internal control cabin (generally in the Mecha's head or chest) via a game controller, exo-mocap, or BCI. If controlled by exo-mocap, usually has haptic feedback. Generally armor-plated and be-weapon-ed. According to TV Tropes tank-sized mecha are "Mini Mecha" and mecha which are several stories tall are "Humongous Mecha". As they put it, if the operator can be described as a "pilot" or "driver", then you have a Mini Mecha on your hands.

Definition: Telerobotics

Telerobotics aka "Drone" or "Remote": In this context, a man amplifier, powered armor, or mecha where the human operator is not inside the machine, but instead is located at some distance using remote control. Control is by either game controller, exo-mocap, or BCI. If controlled by exo-mocap it almost invariably has haptic feedback. If it has weapons, it may or may not have armor, depending upon how expendable it is.

Definition: Cyborg

Cyborg: In this context, a Man Amplifier that is surgically embedded inside the human operator's body. Sometimes also includes other enhancements, such as sensors, life support gear, replacement organs, armor and weapons. Aka "bionics", "six million dollar man".

Definition: Robot

Robot: A man amplifier, powered armor, or mecha where the operator is a computer. Stupid robots only perform pre-programmed tasks (and steal jobs from automobile construction workers). Smart robots with artificial intelligence are disturbing, Asimov's Four Laws of Robotics notwithstanding.

Challenges

There are several challenges standing in the way of creating a useful man amplifier. The primary difficulty is the power supply. The first Iron Man movie got that right, the most important invention of all was the "arc reactor", the miniature fusion reactor that supplies almost unlimited power. Real world man amplifiers use non-rechargeable primary cells, internal combustion engines, and electrochemical fuel cells. These can only power the amplifier for a few hours. For many applications the designers give up and tether the man amplifier to a huge power generator via a power cable.

The material used to construct the exoskeleton is a problem. Aluminum is inexpensive, lightweight, does not stress the motors, and easy to mold. But if the operator is holding an automobile over their head and the aluminum decides to fold up like an accordion (i.e., "fail catastrophically in a high-load condition), the operator will be left feeling quite flat. There are safer but more expensive options like titanium and molded carbon-fiber plates.

The joint actuators (motors) are a problem. Hydraulics have the power and the accuracy, but are heavy due to the fluid-filled hoses and actuator cylinders, and tend to leak hydraulic fluid everywhere. Pneumatics are lighter but since gas is springy the accuracy suffers. Electronic servomotors are a better choice. They are more efficient and power-dense.

Joints are a problem. Human hips and shoulders are ball and socket joints, it is almost impossible to match all the possible human movements with an exoskeleton using single-axis hinges. This limits the operator's flexibility. An exoskeleton with external ball and socket joints have a problem with the series of joints being forced into misalignment. Using a hollow spherical ball joint that encloses the human joint is a better solution, but requires telescoping plates. And the problem of joints in the arms and legs are trivial compared to the nightmare of duplicating the human spine.

Power control and modulation are a problem. The actuators have to not move too fast, over shoot, or otherwise lag behind the operators movement.

Detection of unsafe motions is a problem. You do not want the man amplifier moving in such a way that it breaks the operator's arm, or damages another part of the exoskeleton.

Pinching and joint fouling is a problem. You do not want any part of the exoskeleton's hinges savagely pinching the skin of the operator, nor do you want environmental dust and grit getting into the joints.

Early History

Yes, all you young whipper-snappers think that powered armor is the latest cool thing since the first Iron Man movie came out in 2008. Well, as it turns out, the concept goes a long ways back. Even Iron Man himself goes a ways back, he first appeared in a comic book called Tales of Suspense #39 in March 1963.

The concept of a powered fighting suit arguably dates back to E. E. "Doc" Smith's Children of the Lens (1947) with Kimball Kinnision's armored suit made of pure dureum a quarter of an inch thick. Doc Smith had armored suits back in 1937 with Galactic Patrol but those were not power-assisted. Later came Robert Heinlein's classic Starship Troopers (1959). In "Champion Robot" by E R James (1953), "Creakyfoot" is an eight foot high powered suit for use on farms and in factories. And before that, there were all sorts of bizarre patients for assisted walking/running machines powered by compressed air, wind-up springs, and steam.

Post 1960's powered armor will be covered in the subsequent sections.

The dureum inlay of the glove held, and glove and axe smashed together against the helmet. The Boskonian went down with a crash; but, beyond a broken arm or some such trifle, he wasn’t hurt much. And no armor that a man had to carry around could be made of solid dureum. Hence, Kinnison reversed his weapon and swung again, aiming carefully at a point between the inlay strips.


The Lensman landed, and made his way to Harkleroy’s inner office in what seemed to be an ordinary enough, if somewhat over-size, suit of light space-armor. But it was no more ordinary than it was light. It was a power-house, built of dureum a quarter of an inch thick. Kinnison was not walking in it; he was merely the engineer of a battery of two-thousand-horsepower motors. Unaided, he could not have lifted one leg of that armor off the ground.


Inch by inch, foot by foot, Kinnison fought his way back along the corpse-littered corridor. Under the ravening force of the attackers’ beams his defensive screens flared into pyrotechnic splendor, but they did not go down. Fierce-driven metallic slugs spanged and whanged against the unyielding dureum of his armor; but that, too, held.

Dureum is incredibly massive, unbelievably tough, unimaginably hard— against these qualities and against the thousands of horsepower driving that veritable tank and energizing its screens the zwilniks might just as well have been shining flashlights at him and throwing confetti. His immediate opponents could not touch him, but the Boskonians were bringing up reserves that he didn’t like a little bit; mobile projectors with whose energies even those screens could not cope.

From Children of the Lens by E. E. "Doc" Smith (1947)

Man Amplifier

Originally developed for construction work and back-echelon pack horsing, the General Motors Terrain Walker was quickly accepted by the armies of America, Earth, when it was proved that the machine could carry a gun. Standing twelve feet tall and weighing eight tons, the Walker could stride down a highway at 30 mph and do 20 mph on rough terrain, such as burnt-out slums.

Nuclear powered, it required little servicing and often powered its weapons directly from its own power system. Great hydraulic pistons operated its arms and legs, which followed every movement made by the pilot. The pilot was strapped in a control cradle that translated every motion to the Walker, and he had a clear view fore and aft through a Plexiglas bubble.

The Walker was equipped with a wide range of sensory devices, among them snooper-scopes, radar, amplified hearing, some primitive smell-detection devices and tactile pads on the hands and feet, all of which were wired to the pilot.


The Walkers were instrumental in assisting in heavy construction. They rebuilt the foundations of cities, realigned the world's power conduits, built dams and, in one fierce burst of zealous activity, built almost a hundred thousand miles of beautiful roadway in four years.

Three years after that commercial aircars were produced in profusion. The new roads were ignored and slowly cracked while approaching obsolescence.

From The Warbots by Larry S. Todd, Body Armor: 2000 (1986)

Prosthetics

However, in 233 I.R. (473 A.D.), the Imperium finally made the contact which it had been dreading and preparing for so long; they met with a wandering IRSOL StarCity! This encounter in the otherwise undistinguished Vor Mean (evidently an IRSOL word) System was between the IRSOL StarCity Coroliss 'E' Nyalara and the 10783rd Imperial Exploration and Conquest Squadron under the command of Tara' Alon' T' Elar (Commodore) Shin' Alon (Winter Star).

At first, the IRSOL were overjoyed at meeting a fellow starfaring race, having not the slightest notion as to how the Korellians had gained their FTL technology. They even discounted the call by Commodore Shin' Alon for their unconditional surrender and submission to the Imperium; after all, they surmised, this was merely the bluster with which many races greeted First Contact.

They were rapidly disabused of their complacent attitudes when the Korellian Squadron launched a vicious, and quite unprovoked, attack on the city itself! Though the IRSOL StarForces were, technologically, far superior to the Korellians, the absolute surprise of both the attack and the callously suicidal nature of the tactics of the Korellians utilized in pursuit of their target meant that the initial attack wave got through relatively unopposed and inflicted shockingly heavy civilian casualties.

But worse was yet to come. A Korellian suicide ship managed, by good luck or good aim, to impact directly on the main BattleScreen generators. Before the backups could be activated, the Commodore won himself undying fame in the halls of his ancestors and, indeed, amongst Korells everywhere, by personally piloting his flagship directly into the central area of the city. This totally unexpected attack wiped out a full 73% of the city’s population in one blow — and set off her magazines in a sympathetic explosion. The repeated explosions from this source broke the StarCity's back and resulted in the death of a further 18% of the populace.

The remaining Korellian vessels, except for a few fighters which had been sent back as couriers, were ruthlessly hunted down by the vengeance hungry remnants of the IRSOL StarForces and no prisoners were taken.

From Space Opera: Star Sector Atlas 12 by Phil McGregor (1983)

They were looking ... at a handsome, shapely, dramatic-featured man, eight feet eight inches tall and massing 147 pounds with and ninety-seven pounds without his exoskeleton. Except for relaxed tiny bulges of muscle in forearms and calves (latter to work lengthy toes, useful in gripping), this man was composed of skin, bones, ligaments, fasciae, narrow arteries and veins, nerves, small-size assorted inner organs, ghost muscles, and a big-domed skull with two lumps of jaw muscle. He was wearing a skintight black suit that left bare only his sunken-cheeked, deep-eyes, beautiful tragic face and big, heavy-tendoned hands.

This truly magnificent, romantically handsome, rather lean man was standing on two corrugated-soled titanium footplates. From the outer edge of each rose a narrow titanium T-beam that followed the line of his leg, with a joint (locked now) at the knee, up to another joint with a titanium pelvic girdle and shallow belly support. From the back of this girdle a T-spine rose to support a shoulder yoke and rib cage, all of the same metal. The rib cage was artistically slotted to save weight, so that curving strips followed the line of each of his very prominent ribs.

A continuation of his T-spine up the back of his neck in turn supported a snug, gleaming head basket that rose behind to curve over his shaven cranium, but in front was little more than a jaw shelf and two inward-curving cheekplates stopping just short of his somewhat rudimentary nose...

Slightly lighter T-beams than those for his legs reinforced his arms and housed in their terminal inches his telescoping canes. Numerous black, foam-padded bands attached his whole framework to him.


...Eight small electric motors at the principal joints worked the prosthetic framework by means of steel cables riding in the angles of the T-beams, much like antique dentist drills were worked, I've read. The motors were controlled by myoelectric impulses from his ghost muscles transmitted by sensitive pickups buried in the foam-padded bands.


I tongued pep, instant glucose, and antigrav pills out of their cheekplate container into my mouth. Even the tiny dissolving pellets seemed heavy as osmium on my tongue, and they dropped down my throat like bullets. I followed them with a sip of truly heavy water from my other cheekplate, tilting my exoskulled head to do so.

From A Spectre is Haunting Texas by Fritz Leiber (1969)

Powered Armor

An M.I. lives by his suit the way a K-9 man lives by and with and on his doggie partner. Powered armor is one-half the reason we call ourselves "mobile infantry" instead of just "infantry." (The other half are the spaceships that drop us and the capsules we drop in.) Our suits give us better eyes, better ears, stronger backs (to carry heavier weapons and more ammo), better legs, more intelligence ("intelligence" in the military meaning; a man in a suit can be just as stupid as anybody else only he had better not be), more firepower, greater endurance, less vulnerability.

A suit isn't a space suit—although it can serve as one. It is not primarily armor—although the Knights of the Round Table were not armored as well as we are. It isn't a tank—but a single M.I. private could take on a squadron of those things and knock them off unassisted if anybody was silly enough to put tanks against M.I. A suit is not a ship but it can fly, a little; on the other hand neither spaceships nor atmosphere craft can fight against a man in a suit except by saturation bombing of the area he is in (like burning down a house to get one flea!). Contrariwise we can do many things that no ship—air, submersible, or space—can do.


No need to describe what it looks like, since it has been pictured so often. Suited up, you look like a big steel gorilla, armed with gorilla-sized weapons.

But the suits are considerably stronger than a gorilla. If an M.I. in a suit swapped hugs with a gorilla, the gorilla would be dead, crushed; the M.I. and the suit wouldn't be mussed.

The "muscles," the pseudo-musculature, get all the publicity but it's the control of all that power which merits it. The real genius in the design is that you don't have to control the suit; you just wear it, like your clothes, like skin. Any sort of ship you have to learn to pilot; it takes a long time, a new full set of reflexes, a different and artificial way of thinking. Even riding a bicycle demands an acquired skill, very different from walking, whereas a spaceship oh, brother! I won't live that long. Spaceships are for acrobats who are also mathematicians.

But a suit you just wear.

Two thousand pounds of it, maybe, in full kit—yet the very first time you are fitted into one you can immediately walk, run, jump, lie down, pick up an egg without breaking it (that takes a trifle of practice, but anything improves with practice), dance a jig (if you can dance a jig, that is, without a suit)—and jump right over the house next door and come down to a feather landing.

The secret lies in negative feedback and amplification.


But here is how it works, minus the diagrams. The inside of the suit is a mass of pressure receptors, hundreds of them. You push with the heel of your hand; the suit feels it, amplifies it, pushes with you to take the pressure off the receptors that gave the order to push. That's confusing, but negative feedback is always a confusing idea the first time, even though your body has been doing it ever since you quit kicking helplessly as a baby. Young children are still learning it; that's why they are clumsy. Adolescents and adults do it without knowing they ever learned it—and a man with Parkinson's disease has damaged his circuits for it.

The suit has feedback which causes it to match any motion you make, exactly—but with great force.

Controlled force ... force controlled without your having to think about it. You jump, that heavy suit jumps, but higher than you can jump in your skin. Jump really hard and the suit's jets cut in, amplifying what the suit's leg "muscles" did, giving you a three-jet shove, the axis of pressure of which passes through your center of mass. So you jump over that house next door. Which makes you come down as fast as you went up ... which the suit notes through your proximity & closing gear (a sort of simple-minded radar resembling a proximity fuse) and therefore cuts in the jets again just the right amount to cushion your landing without your having to think about it.

And that is the beauty of a powered suit: you don't have to think about it. You don't have to drive it, fly it, conn it, operate it; you just wear it and it takes its orders directly from your muscles and does for you what your muscles are trying to do. This leaves you with your whole mind free to handle your weapons and notice what is going on around you ... which is supremely important to an infantryman who wants to die in bed. If you load a mud foot down with a lot of gadgets that he has to watch, somebody a lot more simply equipped—say with a stone ax—will sneak up and bash his head in while he is trying to read a vernier.

Your "eyes" and your "ears" are rigged to help you without cluttering up your attention, too. Say you have three audio circuits, common in a marauder suit. The frequency control to maintain tactical security is very complex, at least two frequencies for each circuit both of which are necessary for any signal at all and each of which wobbles under the control of a cesium clock timed to a micromicrosecond with the other end—but all this is no problem of yours. You want circuit A to your squad leader, you bite down once—for circuit B, bite down twice—and so on. The mike is taped to your throat, the plugs are in your ears and can't be jarred out; just talk. Besides that, outside mikes on each side of your helmet give you binaural hearing for your immediate surroundings just as if your head were bare—or you can suppress any noisy neighbors and not miss what your platoon leader is saying simply by turning your head.

Since your head is the one part of your body not involved in the pressure receptors controlling the suit's muscles, you use your head—your jaw muscles, your chin, your neck—to switch things for you and thereby leave your hands free to fight. A chin plate handles all visual displays the way the jaw switch handles the audios. All displays are thrown on a mirror in front of your forehead from where the work is actually going on above and back of your head. All this helmet gear makes you look like a hydrocephalic gorilla but, with luck, the enemy won't live long enough to be offended by your appearance, and it is a very convenient arrangement; you can flip through your several types of radar displays quicker than you can change channels to avoid a commercial—catch a range & bearing, locate your boss, check your flank men, whatever.

If you toss your head like a horse bothered by a fly, your infrared snoopers go up on your forehead—toss it again, they come down. If you let go of your rocket launcher, the suit snaps it back until you need it again. No point in discussing water nipples, air supply, gyros, etc.—the point to all the arrangements is the same: to leave you free to follow your trade, slaughter.


But, in general, powered armor doesn't require practice; it simply does it for you, just the way you were doing it, only better. All but one thing—you can't scratch where it itches. If I ever find a suit that will let me scratch between my shoulder blades, I'll marry it.

There are three main types of M.I. armor: marauder, command, and scout. Scout suits are very fast and very long-range, but lightly armed. Command suits are heavy on go juice and jump juice, are fast and can jump high; they have three times as much comm & radar gear as other suits, and a dead-reckoning tracker, inertial. Marauders are for those guys in ranks with the sleepy look—the executioners.

Starship Troopers by Robert Heinlein (1959)

(ed note: this was written before Pluto's moon Charon was discovered. In the novel Charon is an imaginary planet about twice as far from the Sun as Pluto is. It is cold enough to make Pluto seem like Miami Beach.)

"Now I know you got lectured back on Earth on what a fighting suit can do." The armorer was a small man, partially bald, with no insignia of rank on his coveralls. Sergeant Cortez had told us to call him "sir," since he was a lieutenant.

"But I'd like to reinforce a couple of points, maybe add some things your instructors Earthside weren't clear about or couldn't know. Your First Sergeant was kind enough to consent to being my visual aid. Sergeant?"

Coitez slipped out of his coveralls and came up to the little raised platform where a fighting suit was standing, popped open like a man-shaped clam. He backed into it and slipped his arms into the rigid sleeves. There was a click and the thing swung shut with a sigh. It was bright green with CORTEZ stenciled in white letters on the helmet.

"Camouflage, Sergeant." The green faded to white, then dirty gray. "This is good camouflage for Charon and most of your portal planets," said Cortez, as if from a deep well. "But there are several other combinations available." The gray dappled and brightened to a combination of greens and browns: "Jungle." Then smoothed out to a hard light ochre: "Desert." Dark brown, darker, to a deep flat black: "Night or space."

"Very good, Sergeant To my knowledge, this is the only feature of the suit that was perfected after your training. The control is around your left wrist and is admittedly awkward. But once you find the right combination, it's easy to lock in.

"Now, you didn't get much in-suit training Earthside. We didn't want you to get used to using the thing in a friendly environment. The fighting suit is the deadliest personal weapon ever built, and with no weapon is it easier for the user to kill himself through carelessness. Turn around, Sergeant.

"Case in point." He tapped a large square protuberance between the shoulders. "Exhaust fins. As you know, the suit tries to keep you at a comfortable temperature no matter what the weather's like outside. The material of the suit is as near to a perfect insulator as we could get, consistent with mechanical demands. Therefore, these fins get hot—especially hot, compared to darkside temperatures—as they bleed off the body's heat.

"All you have to do is lean up against a boulder of frozen gas; there's lots of it around. The gas will sublime off faster than it can escape from the fins; in escaping, it will push against the surrounding 'ice' and fracture it... and in about one-hundredth of a second, you have the equivalent of a hand grenade going off right below your neck. You'll never feel a thing.

"Variations on this theme have killed eleven people in the past two months. And they were just building a bunch of huts.

"I assume you know how easily the waldo capabilities can kill you or your companions. Anybody want to shake hands with the sergeant?" He paused, then stepped over and clasped his glove. "He's had lots of practice. Until you have, be extremely careful. You might scratch an itch and wind up breaking your back. Remember, semi-logarithmic response: two pounds' pressure exerts five pounds' force; three pounds' gives ten; four pounds', twenty-three; five pounds', forty-seven. Most of you can muster up a grip of well over a hundred pounds. Theoretically, you could rip a steel girder in two with that, amplified. Actually, you'd destroy the material of your gloves and, at least on Charon, die very quickly. It'd be a race between decompression and flash-freezing. You'd die no matter which won.

"The leg waldos are also dangerous, even though the amplification is less extreme. Until you're really skilled, don't try to run, or jump. You're likely to trip, and that means you're likely to die."

"Charon' s gravity is three-fourths of Earth normal, so it's not too bad. But on a really small world, like Luna, you could take a running jump and not come down for twenty minutes, just keep sailing over the horizon. Maybe bash into a mountain at eighty meters per second. On a small asteroid, it'd be no trick at all to run up to escape velocity and be off on an informal tour of intergalactic space. It's a slow way to travel.

"Tomorrow morning, we'll start teaching you how to stay alive inside this infernal machine.


The suit was fairly comfortable, but it gave you the odd feeling of simultaneously being a marionette and a puppeteer. You apply the impulse to move your leg and the suit picks it up and magnifies it and moves your leg for you.


"Now everybody pay close attention. I'm going out to that blue slab of ice"—it was a big one, about twenty meters away—"and show you something that you'd better know if you want to stay alive."

He walked out in a dozen confident steps. "First I have to heat up a rock—filters down." I squeezed the stud under my armpit and the filter slid into place over my image converter. The captain pointed his (laser) finger at a black rock the size of a basketball, and gave it a short burst. The glare rolled a long shadow of the captain over us and beyond. The rock shattered into a pile of hazy splinters.

"It doesn't take long for these to cool down." He stopped and picked up a piece. "This one is probably twenty or twenty-five degrees (Kelvin). Watch." He tossed the "warm" rock onto the ice slab. It skittered around in a crazy pattern and shot off the side. He tossed another one, and it did the same.

"As you know, you are not quite perfectly insulated. These rocks are about the temperature of the soles of your boots. If you try to stand on a slab of hydrogen, the same thing will happen to you. Except that the rock is already dead.

"The reason for this behavior is that the rock makes a slick interface with the ice—a little puddle of liquid hydrogen—and rides a few molecules above the liquid on a cushion of hydrogen vapor. This makes the rock or you a frictionless bearing as far as the ice is concerned, and you can't stand up without any friction under your boots.

"After you have lived in your suit for a month or so you should be able to survive falling down, but right now you just don't know enough. Watch."

The captain flexed and hopped up onto the slab. His feet shot out from under him and he twisted around in midair, landing on hands and knees. He slipped off and stood on the ground.

"The idea is to keep your exhaust tins from making contact with the frozen gas. Compared to the ice they are as hot as a blast furnace, and contact with any weight behind it will result in an explosion."


The suit is set up to save as much of your body as possible. If you lose part of an arm or a leg, one of sixteen razor-sharp irises closes around your limb with the force of a hydraulic press, snipping it off neatly and sealing the suit before you can die of explosive decompression. Then "trauma maintenance" cauterizes the stump, replaces lost blood, and fills you full of happy-juice and No-shock. So you will either die happy or, if your comrades go on to win the battle, eventually be carried back up to the ship's aid station.

The Forever War by Joe Haldeman (1974)

He leaped clear of the drop boat as it burned around him, landing pack flaring. Six meters above the ground he cut the pack free and dropped, taking the shock of the landing in his armored legs and going with it into a forward tuck-and-roll meant to throw off any targeting gunners. But the drop boat was still drawing the Mishimans' defensive fire; it slewed away clumsily in a flare of jets and steaming ablative as laser fire and missiles broke it open and dropped it flaming to the pocked tarmac of the port. There was no going home now, not unless they won time enough to carve out and hold a secure pickup zone, but Hallorhan wasn't thinking about retreat. Specials weren't supposed to. The platoon was moving out, thirty-six heavy-metal thunder-rapers psyched on gung-ho speeches, fire­power, and high-mike bouncers, and he was supposed to be moving out with them. That was all he had to worry about.

He leaped, current flowing from his enerpacs through the striated "muscle" tissues of his symbioplast armor. The pseudoliving plastic flexed to match the input action of thighs and calves and arching back; alloyed exoskeletal hinges supported organic joints that would have been torn in half under such strains. He landed in the cover of the tail vanes of a wrecked cutter. He looked around, selected a target, and jumped again.

The jump carried him through the line of fire of one of the whirling two-barrel lasers. Its pulses stabbed harmlessly past him with far more power than they needed to kill one man. The weapon was still firing in its ship-killing mode; it took too long to recycle between the heavy pulses for the laser to lay out an effective antipersonnel pattern.

He came down in the gunpit, and the Krupp pulser in his hand speared the man before him with a lance of solid light. His left-hand plasma gauntlet vomited a streamer of incandescent energy and a second man fell back, scream­ing, wreathed in blue flame, to scatter the rest of the guntechs as he was consumed.

The Shattered Stars by Richard McEnroe (1983). If you like the Traveller role playing game, you will like this novel.

Mecha

The difference between an powered exoskeleton and a mecha is pretty straightforwards, but there is still a gray area. Exoskeletons are form-fitting and thus quite close to the size of the operator while mecha are typically huge with the operator inside a control cabin. Having said that, some mecha are controlled by the operator in the cabin wearing an exo-mocap that looks suspiciously like an exoskeleton with no armor (see the McCauley Walker below for an example). Powered exoskeletons are true "man amplifiers", they augment the operator's strength to do tasks. Mecha act more like an operator with a tractor or front-end loader. Mecha range in size from the size of a tank (Armored Trooper Votoms), to a few stories tall (Gundam), to the size of a skyscraper (Space Runaway Ideon), to the size of a city (Macross), or even larger.

The TV Tropes site calls mecha that are tank-sized or smaller "Mini Mecha" while those that are larger are called "Humongous Mecha." As they put it, if the operator can be described as a "pilot" or "driver", then you have a Mini Mecha on your hands. GURPS Mecha defines a "battlesuit" as powered armour where the pilot's arms and legs extend into the suit's arms and legs. A "mecha" is piloted from a cockpit.

Telerobotics

Telerobotics in this context means remotely controlled drone. Ideally we would be talking about a humanoid drone controlled by a remote operator wearing an exo-mocap, but in the real world such drones are conspicuous by their absence.

Unlike robots, drones et al have no on-board brains or AI, they are remotely controlled by a human being. Waldoes are fixed in place, while robot arms like the amazing Canadarm can "walk" from socket to socket like a giant metal caterpillar.

"And you are right, Mr. Chao. It may well be wise to get a gravities man down there." Daltry looked down at his notepack again. "I notice one other thing in your file. You are experienced with teleoperators?"

Larry hesitated a moment. "Well, yes. I am. We use them at the Gravities Station for doing maintenance on the Ring."

"Wait a second," Lucian said. "A teleoperator. A remote-control robot? Those things don’t give you the dexterity or the reflexes you need for this kind of job."

"I agree," Daltry said. "We can’t send a T.O. down by itself. But they do have advantages. They can do heavy lifting. They can carry telemetry. And they are expendable. Of course, we haven’t found the entrance to this so-called Rabbit Hole yet. Maybe we won’t find it in time for Mr. Chao to run the T.O. from the surface. Maybe we’ll never find it. But if we do, it seems to me, Mr. Dreyfuss, that we could send a T.O. down with you."


Lucian stepped into the cage, sat in his crash couch, and turned his head to regard his companion for this little jaunt. It sat there, motionless, on a packing case full of radio relay gear. A humanoid teleoperator. And an ugly one, too: all angles and cameras, wires and servos, more closely resembling a human skeleton than a human. Its dark metal frame was gaunt and wiry, and the object above its shoulders could be called a head only because of its position.

Two primary television camera lenses were more or less where the eyes should go, and two strangely sculpted mikes where the ears should go. But half a dozen other auxiliary camera lenses, and boom and distance mikes, augmented its operator’s senses.


The sweat ran down Larry’s brow. Even just sitting still in this thing was a strain. No matter what he might say to keep Lucian settled down, wearing a teleoperator control rig was tough work. Larry was so thoroughly enveloped in the control rig’s exoskeleton that the comm techs at the other end of the room could barely see him.

The control rig hung in midair, so that the feet would be unconstrained by the floor. He could run, jump, kick, wave his arms, do anything he wanted, and the control rig would stay right where it was, merely waving its limbs about. The teleoperator down below actually moved.

Pressure sensors inside the legs, the arms, the body of the teleoperator itself transmitted their sensations back to servos inside the control rig, providing appropriate physical sensations based on what the T.O. was doing. The mildest of electric shocks susbstituted for a pain response, warning Larry if what he was doing threatened to damage the T.O.

Larry’s head was hidden inside an enormous helmet. Inside it, two video screens displayed the view out of the T.O.‘s cameras. Larry’s earphones merged the faint noises transmitted to the T.O.’s external mikes with the voices on the comm channel.

Wires and gears, levers and sensors: that was what the control rig looked like from the outside.

From in it, things were different. Larry was not in the comm center. He was riding down that huge pit in an open elevator cage, alongside Lucian, the darkness a shroud just outside the feeble lights, the fetid air whistling past his ears. He was there, all his physical sensations keyed to the place he wasn’t.

But he knew that all he felt was unreal. This darkness, this wind, did not surround him. This frightened man in a pressure suit, whom he could reach out and touch, was not there. It was like the strange self-awareness he sometimes felt in a nightmare, knowing the dream was not real, but still experiencing it, accepting the world’s unreality even as he struggled against the demons.

But that sort of detachment had no place in a tele-operator rig. He had to believe, wholeheartedly, that he was down in that shaft.


But the other roller robot grabbed for the teleoperator. Larry, staring through the eyes of the T.O.‘s remote cameras, dodged the first grab and kicked out hard at the manipulator arm. The arm swung back, rebounded against the robot’s body—and then plunged deep into the T.O.’s carapace, seeking not to grasp, but to tear, to rip.

Larry screamed as the control rig shot pain-reflex shocks through his body. The electric charge was not enough to hurt, but Larry was not just in his own body anymore. He was in the T.O., and his chest had just been ripped open. The pain was real, in the place where all pain was real, in the mind, in the soul. He imagined his heart sagging out of his chest wall, shattered ribs hanging at obscene angles. His left leg buckled as a control circuit shorted. He swung out with his right arm, desperately trying to defend himself—but that razor-sharp claw sliced his arm off at the elbow.

Larry screamed again at the pain shock as his arm spun away. Real and imagined, seen through the soul and the TV cameras, he saw his arm shorting and sparking, spewing imaginary bright red blood from hydraulic lines. He saw hallucinated, bleeding flesh visible under the shattered metallic skin. And then another cruel slash, and Larry screamed in a voice that choked off as his head was hacked away from the teleoperator’s body. The T.O.‘s vision switched automatically to the chest cameras. Dead eyes that still could see watched in mindless terror as the T.O.’s head smashed to the littered, filthy ground and the little scavengers began to pick over the teleoperator’s corpse.


They pulled Larry, screaming, from the control rig and put him under with the heaviest anesthetic they could find.


Dr. Simon Raphael sat in Larry Chao’s cabin, watching the Moon grow smaller in the monitor and wondering what it was like to live through decapitation.

Dr. Raphael had never worn a teleoperator control rig himself, but the experts said that the better the rig, the more realism it provided—and the more traumatic the psychic effects of an accident to the teleoperator.

The rig Larry had been wearing was one of the best.

from The Ring of Charon by Roger McBride Allen (1990)

Cyborg

And of course halfway between robots and crew are Cyborgs. Are you old enough to remember the word "bionic?" While it would be a big help to have crew members who do not need to breath or be protected from the temperature extremes of the space environment, there are those who question whether such people are really people at all. More to the point, an SF author has to decide if their readers would rather read about metal men or red-blooded fully human heroes. This is why cyborgs in SF are generally either the main character in a world of humans or a small population of peripheral bit players.

NASA is a little uncomfortable with the concept as well. Which is a pity, since a properly designed cyborg would be far superior space travelers compared to us pathetic humans. Implant internal oxygen tanks to remove the need for breathing, implant food tanks to remove the need for eating, and implant an electrode in the pleasure center of their brain to remove the scourge of boredom. You could really save on life support mass by using cyborgs.

The concept of a cyborg covers quite a broad range though. At one end of the spectrum it is quite common to find people who have intraocular lenses in their eyes due to cataract surgery. At the other end one almost never encounters a robot body controlled by a human brain floating in a tank.

In the role playing game Universe, people with enough money can have an "internal gravity web" surgically implanted. This is a series of strong nets anchored to bone that support the internal organs. It allows the person to undergo accelerations larger than 2.5g indefinitely with no ill effects.

In Anne McCaffrey's Brain & Brawn Ship series, The parents of babies with brilliant minds but severe physical disabilities can opt to have their child become a "shell person" instead of being euthanised. They are not quite just a brain in a tank, but the difference is academic. One of the ways a shell person pays off their training debt is by hiring out on a "brainship", basically becoming a cyborg with a starship for a body.

Striding buoyantly across the low-gravity surface of the moon, there may someday be strange new men — part human, part machine — like the ones above. They will have a strange name: CYBORGS (for CYBernetic ORGanisms). Cyborgs, according to the daring new idea, will be men whose body organs and systems are automatically adjusted for life in unearthly environments by artificial organs and senses. Some of these devices will be attached, others actually implanted by surgery. With their aid cyborgs can dispense with clumsy, easy-to-puncture space suits in which earth conditions are recreated. Instead they can move about safely wearing not much more than they would at home.

The artificial senses of cyborgs will measure changes inside the body and outside in the environment. They will signal artificial glands telling them what to secrete for regulating normal body functions. Then body temperature may fall to that of a fish in ice, or the pulse may quicken like a robin’s in flight, but the human organism will survive. Fantastic as the idea sounds, its originators (see next page) think that it is feasible and that much of the knowledge needed already exists.

From MAN REMADE TO LIVE IN SPACE in Life Magazine July 11, 1960. Artwork by Fred Freeman

"Eric, you there?"

"Where would I go?" he mocked me.

"Well," said I, "if I watched every word I spoke I'd never get anything said." All the same, I had been tactless. Eric had had a bad accident once, very bad. He wouldn't be going anywhere unless the ship went along.

"Touché," said Eric.


"I'd better check your maintenance."

"Okay, good. Go oil my prosthetic aids."

"Prosthetic aids"—that was a hot one. I'd thought it up myself. I pushed the coffee button so it would be ready when I was through, then opened the big door in the forward wall of the cabin. Eric looked much like an electrical network, except for the gray mass at the top which was his brain. In all directions from his spinal cord and brain, connected at the walls of the intricately shaped glass-and-soft-plastic vessel which housed him, Eric's nerves reached out to master the ship. The instruments which mastered Eric—but he was sensitive about having it put that way—were banked along both sides of the closet. The blood pump pumped rhythmically, seventy beats a minute.


"Jackass! Am I still alive?"

"The instruments think so. But I'd better lower your fluid temperature a fraction." I did. Ever since we'd landed I'd had a tendency to keep temperatures too high. "Everything else looks okay. Except your food tank is getting low."

"Well, it'll last the trip."

"Yeah.

"'Scuse me. Eric, coffees ready." I went and got it. The only thing I really worry about is his "liver." It's too complicated. It could break down too easily. If it stopped making blood sugar Eric would be dead.

If Eric dies I die, because Eric is the ship. If I die Eric dies, insane, because he can't sleep unless I set his prosthetic aids.

From "The Coldest Place" by Larry Niven (1964)

Beyond the four-foot-square access door was Eric. Eric's central nervous system, with the brain perched at the top and the spinal cord coiled in a loose spiral to fit more compactly into the transparent glass-and-sponge-plastic housing. Hundreds of wires from all over the ship led to the glass walls, where they were joined to selected nerves which spread like an electrical network from the central coil of nervous tissue and fatty protective membrane.

Space leaves no cripples; and don't call Eric a cripple, because he doesn't like it. In a way he's the ideal spaceman. His life support system weighs only half of what mine does, and takes up a twelfth as much room. But his other prosthetic aids take up most of the ship. The ramjets were hooked into the last pair of nerve trunks, the nerves which once moved his legs, and dozens of finer nerves in those trunks sensed and regulated fuel feed, ram temperature, differential acceleration, intake aperture dilation, and spark pulse. These connections were intact. I checked them four different ways without finding the slightest reason why they shouldn't be working.

"Test the others," said Eric.

It took a good two hours to check every trunk nerve connection. They were all solid. The blood pump was chugging along, and the fluid was rich enough, which killed the idea that the ram nerves might have "gone to sleep" from lack of nutrients or oxygen. Since the lab is one of his prosthetic aids, I let Eric analyze his own blood sugar, hoping that the "liver" had goofed and was producing some other form of sugar. The conclusions were appalling. There was nothing wrong with Eric—inside the cabin.

From "Becalmed in Hell" by Larry Niven (1965)

In the "Professor Jameson" novels by Neil R. Jones, the only organic part left in the Zoromes are the brains inside the conical "heads", the rest is machinery. Zoromes are functionally immortal, as long as their conical heads are not damaged. They require no air, food, nor sleep. They do require a minimum amount of heat, but that's about it. They do have various accessories they can attach to their bodies, such as flying wings.

The Professor Jameson stories were one of the longest running SF series, twenty-one stories between 1931 and 1951. Which is surprising since the writing is so tediously bad. The series did influence several SF authors. Isaac Asimov said they were the inspiration for his benevolent positronic robots. Masamune Shirow paid homage to Jones in his cyborg-populated Ghost in the Shell saga by including a no-frills brain-in-a-box design, even naming them Jameson-type cyborgs.

Within the interior of the space traveler, queer creatures of metal labored at the controls of the space flyer which juggernauted on its way towards the far-off solar luminary. Rapidly it crossed the orbits of Neptune and Uranus and headed sunward. The bodies of these queer creatures were square blocks of a metal closely resembling steel, while for appendages, the metal cube was upheld by four jointed legs capable of movement. A set of six tentacles, all metal, like the rest of the body, curved outward from the upper half of the cubic body. Surmounting it was a queer-shaped head rising to a peak in the center and equipped with a circle of eyes all the way around the head. The creatures, with their mechanical eyes equipped with metal shutters, could see in all directions. A single eye pointed directly upward, being situated in the space of the peaked head, resting in a slight depression of the cranium.

From "The Jameson Satellite" by Neil R. Jones (1931)

Robot

If the operator is actually a computer instead of a human being, you have a Robot. It would be so much more convenient to use an all robot crew, were it not for Burnside's Zeroth Law.

ROBOTS. These have mostly disappeared, except for a few amusing ones in Star Wars movies, and the recent proliferation of GIANT WAR ROBOTS. Apart from these, the decline of Robots is striking, and my guess is that it happened for two reasons.

1) They have made so little progress in the real world. ("Industrial Robots" don't count as real Robots.) I'm typing this on a computer vastly more powerful than the enormous Central Computers of 1950s SF, but I still don't have a household Robot to do the dishes. AI, needed for real Robots, hasn't much panned out, so people have tended to cool on the whole thing.

2) Isaac Asimov. He ruined it for the old-fashioned malevolent Robots, and pretty much exhausted the possibilities of the other kind. Even HOLLYWOOD SCIFI hardly uses traditional Robots any more, though Giant War Robots will doubtless turn up soon at a 50-plex near you.

When Robots do appear in written SF, TECHJARGON may shorten the term to simply Bots.

From The Tough Guide to the Known Galaxy by Rick Robinson

In principle Defiant was a better ship than she'd been when she left New Chicago. The engineers had automated all routine spacekeeping tasks, and no United Republic spacer needed to do a job that a robot could perform. Like all of New Chicago's ships, and like few of the Imperial Navy's, Defiant was as automated as a merchantman.

Colvin wondered. Merchantmen do not fight battles. A merchant captain need not worry about random holes punched through his hull. He can ignore the risk that any given piece of equipment will be smashed at any instant. He will never have only minutes to keep his ship fighting or see her destroyed in an instant of blinding heat.

No robot could cope with the complexity of decisions damage control could generate, and if there were such a robot it might easily be the first item destroyed in battle. Colvin had been a merchant captain and had seen no reason to object to the Republic's naval policies, but now that he had experience in warship command, he understood why the Imperials automated as little as possible and kept the crew in working routine tasks: washing down corridors and changing air filters, scrubbing pots and inspecting the hull. Imperial crews might grumble about the work, but they were never idle. After six months, Defiant was a better ship, but...

From "Reflex" by Larry Niven and Jerry Pournelle (the deleted first chapter of The Mote in God's Eye, collected in There Will Be War I)

Fractal Robot

Hans P. Moravec of the Carnegie-Mellon University invented a unique robot design that he calls "Bush robots." One was featured in The Flight of the Dragonfly (AKA Rocheworld) written by Dr. Robert Forward (called the "Christmas Bush" because it is covered in millions of tiny red and green lasers). It can be described as a "fractal robot." Center pivot with six arms. Each arm subdivided into six smaller arms. This repeats quite a few times. The finest arms can reach into a piece of machinery through a tiny hole, fan out, and repair the inside of the machine. Arm segments can also detach for separate jobs. The entire assembly is controlled by the master computer.

In Dr. Moravec's words:

Once upon a time animals were shaped like sticks (worms), and couldn't manipulate or even locomote very well. Then the sticks grew smaller sticks and locomotion was much improved, and manipulation a little. Then the smaller sticks grew yet smaller sticks, and hands were invented, and manipulation got better.

Generalize the concept. I visualize a robot that looks like a tree, with a big stem, repeatedly branching into thinner, shorter and more numerous twigs, finally ending up in jillions of near-microscopic cilia. Each intermediate branch would have three or four degrees of freedom, an azimuth-elevation mount at its base, and an axial rotation joint at the top, where it connects to the next level of smaller twigs, and possibly also a length altering telescoping joint. To a large extent fewer degrees of freedom per level can be traded off for more levels. Each branch would also incorporate force sensing. Though each branch would be a rigid "mechanical" object, the overall structure would have an "organic" flexibility because of the great multitude of degrees of freedom.

Dr. Hans P. Moravec

You can read Dr. Moravec's NASA sponsored report here.

In the movie 2001, the arms of the pod have a similar fractal arrangement, each arm splitting into two, each of which further splits into two fingers.