This is from Advanced beamed-energy and field propulsion concepts (chapter XIV) by the BDM Corporation (1983). Unsurprisingly the study was performed with support from DARPA under contract number DAAH01-80-C-1587.
The point of the report is to figure out the Technology Readiness Level of using nuclear reactors in manned combat spacecraft armed to the teeth. Granted there is currently no pressing need for such spacecraft, but DARPA is all about not allowing the military to get caught with its pants down. Again.
As an interesting side note: the report specifically mentions that since the battle cruiser is equipped with a gigawatt laser, it can be used to assist small laser thermal craft to boost into orbit. In other words, a laser-launch system where the laser was located in orbit instead of on the ground. Report specifically mentions a single-stage-to-orbit laser-powered spacecraft called a "Monocle Shuttle."
This would also be useful to energize laser-powered space fighters, like the Hegemony Interceptors. It could also energize combat mirrors and other powersat weapons. Or other beamed power applications. Oh, did I mention that the Monocle Shuttles could also be used as mobile laser combat mirrors?
The difference is that powersats generally have no propulsion system, but the battle crusier is mobile. Oh, and the unfortunate fact that powersats have unlimited power by virtue of solar arrays with the surface area of Rhode Island, but the battle cruiser has drastically limited amounts of reactor coolant.
The study spacecraft would be armed with a free-electron laser, a particle-beam weapon, a railgun, and possibly a microwave weapon. All of these weapons were purposely selected because they are power hogs, and would need plenty of nuclear power. The power requirements would be in the range of tens of megawatts to a few gigawatts, in a "burst" mode that will run from one to a hundred seconds in duration. The power demand will be instant: within no more than a few seconds.
The spacecraft will require multi-mode reactors. The reactors can operate as [a] a high-thrust nuclear thermal rocket, [b] a peak power electrical generator, and [c] a lower powered stationkeeping electrical generator. As a peak power generator it will operate in open-cycle mode and energize either a MHD generator or a turbogenerator.
Since open-cycle mode wastes reactor coolant at an alarming rate, the instant the weapon no longer requires electricity the reactor will switch to closed-cycle mode. This will allow removal of reactor decay heat without blowing precious coolant overboard. Open-cycle cooling is required for burst mode because closed-cycle is not up to the task of preventing the reactor from melting. Closed-cycle can handle cool-off or stationkeeping reactor levels, since the power levels are only about 3% or 4% of burst mode.
The report comes to the conclusion that solid-core reactors cannot handle burst mode without going all Chernobyl on you. It will have to use fixed or rotation particle bed reactors (RBR). Burst mode will create such high thermomechanically induces stresses on the solid core elements that it will cause immediate core failure. At least without gradually powering up while wasting even more coolant in open-cycle mode.
Obviously such huge power levels are going to create ugly amounts of waste heat. Both from the reactor and from the weapon system. The burst power and weapon heat will be dealt with via open cycle cooling. Reactor decay heat will be taken care of by heat radiators. Lots and lots of heat radiators. So much heat radiator that you'd better be using the most lightweight radiator design possible.
This looks like a job for Liquid Droplet Radiators (LDR). Not only due to the low mass, but they are also the hardest to damage with hostile weapons fire. Which is always a plus on a warship.
The radiators are 60° triangles. The droplet collector is hinged so it can retract into the body of the spacecraft fuselage during surface-to-orbit launch. The generator is rigidly attached to the hull, and is divided into a large number of droplet generator modules. Each module has its own piezoelectric shaker and electromagnetically activated shut-off valve. The large number of droplet generators gives gracefule degradation and redundancy, always a plus for any equipment that the enemy is going to be taking pot-shots at.
There will be three heat radiators, one for each of the nuclear reactors.
The spacecraft has three nuclear reactors/engines, three triangular LDRs for the three engines, and two smaller LDRs for the habitat module. It is 150 meters long. A Space Shuttle orbiter is shown docking to the command module for scale.
Each of the three multi-mode powerplants uses a rotating bed particle reactor (RBR) design. Each produces 2,500 MWth and has its own 100 MWth liquid droplet radiator (LDR) with a closed-cycle conversion system. The triangular LDRs are 100 meters on a side. They take care of the waste heat when the reactor is being used in low-power housekeeping mode. In this mode, the three reactors produce a combined total of 75 MWe. Each reactor has an anti-radiation shadow shield, to protect the crew and ship structure from reactor radiation.
The LDRs are mounted to the aft 100 meters of the 150 meter long spacecraft. Inside the 100 meter core of the ship are mounted six LH2 cryogenic shuttle External Tanks (ET). The liquid hydrogen is used for open-cycle cooling and for engine propellant. The reactors, powerplants, and propellant tanks are bolted on to the space-frame trusses of the ship's spine. They are protected with light-weight anti-laser ablative armor.
The forward 50 meters of the spacecraft is the Command Module. This contains the habitat module the crew lives in. It has smaller LDRs that are only 40 meters on a side, used to keep the habitat module environment temperature comfortable. The Command Module is separated from the rest of the spacecraft by a secondary radiation shield. Hey! There are three nuclear reactors back there, and they blaze with blue radioactive death in burst mode.
The Command Module contains two "bridges" (actually CICs). The main one is a 20 meter diameter artificial gravity centrifuge that provides 1 gravity (it will have to spin at 9.4 rpm which is right at the nausea limit).
The smaller "heavily shielded forward bridge area" is where the crew shelters when they fire the particle-beam weapon (PBW) or the free-electron laser (FEL). Those weapons create radiation even when they are operating perfectly. But the PBW has a worst-case failure mode where the beam is misdirected back at the crew. The thickness of the bridge shield is designed to mitigate the maximum inflicted dose before the PBW can be shut down. The crew might be safe from the FEL if they are in the main bridge and only protected by the secondary radiation shield. But they MUST shelter in the secondary bridge if the PBW is going to be fired.
The three reactors are mounted on short struts so to keep the large LDRs within the shadow of the shadow shield. Otherwise they will backscatter radiation into the crew. The LDRs may backscatter radiation from the FEL onto the crew, which is why it might be a good idea to play it safe and shelter in the secondary bridge anyway.
The Free-Electron Laser proper is located in the rear of the spacecraft, nestled among the LH2 tanks.An accelerator is used to move the free-electrons. An RF LINAC, a storage ring, or an induction LINAC electron accelerator can be used. They create dangerous radiation so you want them away from the crew. The FEL "wiggler" is located halfway between the aft end of the spacecraft and the grazing incidence resonance optics.
The beam travels forwards, passing along the belly of the command module. It hits the grazing incidence secondary optics and is directed "upwards" into the telescope mount and the extended beam expander. This is basically a huge laser turret. The beam expander had been focused on the enemy target, and directs the laser beam to burn a red-hot hole in it.
The large beam expander has its back side (the non-mirror part) armored, to protect against hostile weapons fire. The entire expander is designed to be retractable in case the enemy starts throwing nuclear weapons around. The high-reflectivity multi-layer film coating of the expander is rather delicate.
The neutral particle-beam weapon (NPBW) will be mounted parallel to the FEL. The only difference is it fires directly backwards. The blasted beam is basically radioactive, so you want it as far from the crew as possible. The NPBW is in a spinal mount unlike the FEL, so you aim it by rotating the entire ship. Actually aiming the ship's rear. Remember the worst case failure mode is the weapon firing in reverse, directly forwards into the crew.
The length of the railgun depends upon how fast you want the projectile to go, and how much acceleration the railgun can manage. It will fire forwards, and it too will be in a spinal mount.
I tried to make a Blender model of the battle cruiser. It was not easy since the scans in the report are beyond terrible. About as good as a forth-generation photocopy. So don't blame me if the ship looks wonky. If anybody has access to a better scan of the report, please get in touch with me.
|6.18 MN||2.2 MN|
|Accel||10 m/s2||4.58 m/s2|
|1,132.4 kg/s||1,000 kg/s|
|5,457 m/s||2,200 m/s|
|556.2 s||452.3 s|
|770 s||105 s|
|≈2 hrs||5.56 days|
|Δv||7,842 m/s||4,947 m/s|
The Liberty Bell proper is a command module with a dry mass of 50 tons, and 50 tons of propellant. It has a power plant, life support, and thrusters. It can carry a crew of five plus up to 20 passengers from the surface into LEO.
On the nose is an airlock with an androgynous docking port and a maneuvering unit.
On the tail there are four couplers, each of which can hold one cargo container. The containers are cylinders 9.5 meters long and 5 meters in diameter. They are rated to carry a maximum of 62.5 tons of cargo each.
There are four remote manipulator arms used to handle cargo containers. The arms are not permanently attached, they can move like a giant inchworm over the spacecraft's surface just like the Canadarm 2 on the International Space Station.
The Liberty Bell is boosted into orbit with an L-Drive assembly. This is a laser launch system. At the spaceport, the launch pad has a huge stationary laser built into it. The L-Drive assembly is attached to the bottom of the Liberty Bell. The L-Drive is an air-breather, it scoops up atmosphere and sprays it into the mirrored dish-with-a-spike. The laser beam from the launch pad heats the air, creating the thrust to boost the spacecraft into orbit. The laser beam tracks the L-Drive as it climbs into the sky. When the L-Drive reaches an altitude where the air is too thin, it switches to its internal propellant tanks.
Typically the L-Drives are owned and maintained by the spaceport, they cost $1,250,000 Black Desert dollars. The spaceport will rent an L-Drive, laser boost time, plus fees and taxes to the captain of the Liberty Bell. This will cost the captain $100,000 total to boost the Liberty Bell into LEO.
Upon reaching LEO, a Liberty Bell generally makes a rendezvous with an orbital transport nexus, unloads its four cargo containers (250 tons of cargo total) and 20 passengers, loads new cargo and new passengers to be delivered to Terra's surface, pays the spaceport for laser landing services (including fresh propellant for the L-Drive), and rides the laser beam back down to the spaceport.
However, our Liberty Bell is heading to Luna.
The Liberty Bell jettisons the L-Drive, delivering the rental vehicle back into the hands of spaceport personnel (the orbital representatives). The captain knows that when they make the return trip, the spaceport will be more than happy to reserve them an L-Drive for the trip down.
On this trip, instead of carrying four cargo containers, the Liberty Bell only has two containers (125 tons), a translunar rocket engine (20 tons, thrust equivalent to a SSME), and a small cobbled together weapons package (105 tons). The total payload tonnage is 250 tons, same as four cargo containers.
The weapons package contains two Kinetic Kill Vehicles (KKV) at 40 tons each, two Caltrop space mines at ten tons each, and a laser turret with power supply at five tons.
The Liberty Bell then moves into a higher orbit, to make a rendezvous with a transfer space station. In the Black Desert universe, the orbits are patrolled by the astromilitaries of various nations, all looking for trouble and whatever they can get away with. This is the main reason for the Liberty Bell's weapons package.
At the transfer station, the Liberty Bell outfits itself for the Lunar trip. It leases four propellant tanks to feed the translunar rocket engine. It also leases or purchases a cupola.
Using the remote manipulator arms, the translunar rocket engine and the airlock/docking ring swap positions. The rocket engine is mounted on the nose and the four propellant tanks are attached. The docking ring is mounted next to the other cargo, and a cupola installed on top. For the rest of the trip, the cupola will serve as the Liberty Bell's cockpit.
As it turns out, one of the captain's business partners had three cargo containers waiting at the transfer station to be delivered to Luna. The remote manipulator arms install these as well.
The Liberty Bell is ready for the trip to Luna. The command module now faces opposite the direction of thrust it had at launch, with the cupola and the weapons package aimed at the new forwards that used to be backwards. It is carrying three hundred tons of cargo.
It has enough life support and consumables to haul five crew and twenty passengers on the five and a half day trip to Luna or one of the La Grange stations.
Rocketpunk Patrol Ship
Dry Mass 76.2 metric tons Wet Mass 384.6 metric tons Mass Ratio 5 Length Z 73 meters Length Y 20.1 meters Length X 15.2 meters Engine x2 F-26-A LH/LOX Thrust 7.7×106 N Acceleration 0.5 g ΔV 8,200 m/s
This is the same one from the other day, only dressed up with a nice logo and some stats. These are realistic capabilities made courtesy of the charts and other information available from Atomic Rocket and inspiration from Rick Robinson's Rocketpunk Manifesto.
My PL differs from the one in Rick Robinson's article in a few key areas. The main difference is that it is not made for long hauls. It only has a delta v of about 8200 m/s. This will not get one far in the solar system but it allows a forward deployed Patrol Craft a sufficient "range" to perform many of the missions we discussed in the last post on Building a Space Navy. Our little A-Class has enough Delta V to shape a light-second orbit around a convoy in deep space, conduct SAR missions anywhere in cis-lunar space, or to reach any moon of Saturn from any other moon. Obviously, this rocket is mostly propellant (mass ratio 5). If you drew lines through the side view of the rocket that bracket the docking rings, you would encompass the entire pressurized volume. I've got to say, it's nice to work on a warship for a change — I don't have to make it economical to run!
One of the interesting things about this design is actually the freedom the little carried craft gives me. It was a throw-away touch, originally — a design borrowed from another project. But as I got to looking at the little thing, I realized that it's about the size of the Saturn V stage/Apollo/LM stack. That means it should be able to go from Earth Departure to Lunar orbit. That means that it has the Delta V to ferry crew to and from a Patrol Craft on station away from the convoy. That means, like submarines, our Patrol Craft can have two crews and stay out for a lot longer than otherwise. This is one of those realistic touches that I hope add to the charm of the rocket's design.
ed note: a 1500 nanometer near infrared laser with a 10 meter fixed mirror can have a 4 centimeter spot size out to 220 kilometers or so. A 4 meter mirror can have a 4 centimeter spot size out to 87 kilometers or so.
Charles Oines is an emergency stunt artist who has been producing game-related digital artwork since 1990 for a variety of high-profile game companies. Do go check out his portfolio. The artwork displayed below was created for the game Attack Vector: Tactical.
The spherical mesh is a species of fusion drive, the spikes are propulsion system heat radiators. The rectangular vanes are the power reactor and weapon system heat radiators. The forward part of the propulsion system is a lead and concrete radiation shadow shield.
Recently, Mr. Oines has mastered the art of creating 3D meshes suitable for rapid prototyping. He now offers a selection of starship miniatures suitable for starship wargames from his print-on-demand ship.
He also has a paper-and-cardboard starship wargame that offers valuable lessons in maneuvering spacecraft under Newtonian physics.
Daniel McIlvaney's impressive artwork can be found on SciFi Meshes, where he goes by the handle "TheUnlogicalOne". The first set of images are of a patrol ship, and second is of a destroyer. Mr. McIlvaney hastens to add that these are all works-in-progress, not finished works.
Spacedock: A series where we look at the specifications, history and lore of fictional spacecraft from science fiction. Any Spacecraft, any Sci-Fi.
Recently they entered into a agreement with the TV show The Expanse to produce the series FORCE RECON: THE SHIPS OF THE EXPANSE about the various spacecraft. The series is produced in collaboration with The Expanse team and constitutes official Expanse canon (meaning Spacedock is not just making up fan crap on their own, the TV show considers this to be official). Please note that while the videos are canon to the TV series, they may or may not be compatible with the book series.
Subscribe to Spacedock's Expanse Channel in order to be notified of each new video release.
Truman Class Dreadnought
Morrigan Class Patrol Destroyer
Razorback Racing Pinnace
Leonidas Class Battleship
Scirocco Class Assault Cruiser
Amun-Ra Class Stealth Frigate
Artist Juho Kesälä is a long time fan of this website, and uses it ensure the reality of the artwork.
My scifi setting originated and still serves as a vehicle for storytelling, art and gaming, but I've also found worldbuilding in on itself an enjoyable pursuit. One of the things I like to do is design spacecraft with some level of realism. I strive to keep things at least physically plausible with the fairly significant exception of faster-than-light travel. Call it hard scifi space opera, if that's not too much of an oxymoron. Much of my inspiration for these designs comes from setting myself design constraints and then coming up with ideas to satisfy them.
In terms of artistic influence I'd have to mention Homeworld.
Currently all this stuff exists mostly in my head, a few story and gaming related projects, and a folder on my computer. Though the worldbuilding isn't collected anywhere online I do have a Tumblr and a DeviantArt account where I'll post my artwork.
|Wet Mass||6,590,000 kg|
|Dry Mass||2,012,000 kg|
|Exhaust Velocity||852,800 m/s|
|Specific Impulse||86,900 sec|
|Thrust Power||132 terawatts|
|Armament||2 x ion cannon|
The propulsion system is called the "cascade drive", which from the description appears to be a species of antimatter-catalyzed-microfission Hydrogen-Boron fusion. The specific impulse for the cascade drive is a bit more than the info I have about the HB drive but it is in the same order of magnitude. Fuel pellets containing Hydrogen-Boron and Uranium 235 (in a 9:1 molar ratio) are fired into the center of a magnetic nozzle. Antimatter beams shoot streams of antiprotons at the pellet. The antiprotons cause the uranium to fission. The fission energy ignites the hydrogen-boron fuel into a fusion reaction. The magnetic nozzle turns the fusion energy into thrust. The pellets are ignited at about 1 second intervals.
In fleet combat, the tiny Nikto-egas are interceptors. Their relatively high acceleration and delta-V give them a huge reach. The main function is to intercept hostile missile fire in the early boost stage. The idea is the threat of the intercepter forces the missile to shed their high delta-V boost stages, or be destroyed by interceptor ion cannon fire. Without the boost stage, the missiles can no longer reach their original target, so they have to retarget on the relatively low-value interceptors. The interceptors are designed to survive this, but interceptor attrition rates are inevitably high.
To endure the savage four to eight gee acceleration, the 3 man crew uses liquid breathing. This is appropriate since "nikto-ega" is a species of small predatory fish.
The interceptor can carry up to four mission-specific payload pods. These include missile pods, electronic warfare, sensors, and drones.
Warning: spoilers for the book Footfall by Larry Niven and Jerry Pournelle to follow. On the other hand, the novel came out decades ago in 1985. I mean, in the novel the U.S.S.R. still exists. It takes place in the far flung future year 1995.
Aliens (called "Fithp") who look like baby elephants arrive from Alpha Centauri in a Bussard ramjet starship (hybrid Sleeper ship and Generation ship). The starship is named "Message Bearer." They immediately ditch the Bussard drive module into the Sun, destroying it. If the Fithp are defeated, the humans can jolly well build their own Bussard drive from scratch to travel to Alpha C and attack the Fithp homeworld.
The Fithp evolved from herd animals, unlike humans. They have a very alien idea of conflict resolution. When two herds meet, they fight until it was obvious which one was superior. Then everybody immediately stops fighting, and the inferior herd is peacefully incorporated into the superior tribe as second-class citizens. Fithp do not comprehend the concept of "diplomacy".
They make the unwise assumption that human beings operate the same way. Big mistake!
The Fithp have somewhat superior technology compared to humans. They attack and seize the Russian space station (the ISS was not started until 13 years after the novel was written), annihilate military sites and important infrastructure with rods from God, then invade Kansas. The Fithp think "Look, humans. We are obviously superior. Now is the time to stop fighting and be peacefully incorporated into our herd." The Fithp calmly wait for the human surrender.
Humans don't work that way (and they have no idea that the Fithp have such a bizarre way of interacting). They savagely counterattack with the National Guard and three US armored divisions. The Fithp are taken aback, and beat off the counterattack with orbital lasers and more rods from God. The humans respond with a combined Russian and US nuclear strike on Kansas, obliterating the Fithp invasion force and most of the Kansas heartland.
The Fithp start panicking. What is it going to take to make these crazy humans surrender?
Finally the Fithp decide to forgo all half-measures. They drop a small "dinosaur killer" asteroid on Terra. The asteroid is called "The Foot." This causes global environmental damage, and more or less kills everybody living in India. Surely this will make the humans surrender!
The Fithp obviously don't know humans very well.
The humans have their backs to the wall, since surrender is not in their nature. The US president has a tiger team of advisers, who were drawn from the ranks of science fiction authors. After all, they are the only experts on alien invasions (in the novel, the various advisers are thinly disguised versions of actual real-world authors. Nat Reynolds is Larry Niven, Wade Curtis is Jerry Pournelle, and Bob Anson is Robert Anson Heinlein). They have got to find a way to carry the battle to the enemy: the orbiting starship and the fleet of "digit" ships. But how do you get thousands of tons of military hardware into orbit quickly enough not to be shot down while in flight using only technology they can develop in a dozen months?
There is only one answer. Project Orion. Old boom-boom. And to heck with the limited nuclear test-ban treaty that killed the project in 1963.
Orion has already been developed. Orion is mass-insensitive, it doesn't care if you are boosting tens of thousands of metric tons. This also means you can use quick and dirty engineering, since you are not stopping every five minutes trying to shave off a few grams of excess mass. You don't have to spend a decade trying to engineer featherweight kinetic energy weapons, just go tear the gun turrets off the Battleship New Jersey and weld 'em on. You can also carry a fleet of gunboats. And all four space shuttles.
The gunboats are going to be quick and dirty as well. Spaceships built around a main gun off a Navy ship, firing nuclear shells. Yes, a spinal mounted weapon
What about the Orion drive battleship's main weapon? Heh. Another cancelled project rises from the grave.
Back in the days of the Strategic Defense Initiative, Edward Teller et al came up with Project Excalibur. What was that? No less than bomb-pumped x-ray lasers. But wait, what about the bomb you need to pump the laser? Well, Orion is an nuclear-bomb-powered drive, remember? Make the propulsive bombs do double duty.
The weapons are called "spurt bombs." Dispensers on the pusher plate eject a flight of the little darlings. The spurt bombs unfurl their 100 laser rods apiece and aim them at Fithp ships. The next nuclear pulse unit is positioned, then detonated. This simultaneously gives thrust to the spacecraft, and pumps all of the spurts bombs. The Fithp ships are sliced and diced by a hail of x-ray laser beams. Spurt bombs look like fasces, "bundles of tubes around an axis made up of attitude jets and cameras and a computer."
Note that the nuclear pulse units will have to be specially designed. Standard Orion pulse units are nuclear shaped charges, designed to channel 80% of the x-rays upwards into the pusher plate (well, to create a jet of plasma directed at the plate but I digress). The battleship's pulse units need to be designed to also direct x-rays at the spurt bombs.
What is the battleship's name? Michael of course. The Biblical Archangel who cast Lucifer out of heaven.
The Michael launches through a cloud of Fithp digit ships, cutting them to pieces but suffering serious damage. The Fithp defecate in their pants and frantically rip the starship out of orbit and start running away. Their superior acceleration make escape possible, up until the point where the crew of the Space Shuttle Atlantis commits suicide and rams the starship. The main drive is damaged, and their acceleration is no longer higher than the Michael. Who catches up and starts pounding the living snot out of the starship.
There is something breathtaking about the Michael that captures the imagination of science fiction fans. On pretty much every single online forum about spacecraft combat, it isn't long until somebody brings it up. There have been many examples of fans trying to make blueprints, illustrations, or even scratch-build models of the battleship.
The original Michael diagram was made by Aldo Spadoni, president of Aerospace Imagineering. Mr. Spadoni is an MIT educated mechanical/aerospace engineer with over 30 years of experience designing and developing advanced aerospace vehicle and weapon system concepts (with most of the more advanced work being classified). He is also a personal friend of Larry Niven and Jerry Pournelle.
Mr. Spadoni did the Michael diagrams around 1997, working directly with Niven and Pournelle. They went through several iterations to arrive at the resulting diagrams.
Around 2010 Andrew Presby and I were commissioned by Aldo Spadoni to turn his Michael blueprints into 3D renders. Click for larger images.
Now, strictly by the novel, the Michael is a mile high, which is ludicrous. The protagonists would have to have built a mile-high dome to cover it, which the aliens might have found a bit suspicious. In the diagrams below, Mr. Lowther shows the "large" Michael (one mile) and the more reasonable "small" Michael (1/8th mile).
Nightrider is a fascinating novel by David Mace. Nightrider is a military spacecraft with an experimental gravity drive, along with more conventional fusion drives.
In the Nightrider universe, military ships can be easily tracked by their brilliant fusion drive plumes. After each burn, the ship can no longer be detected, however this does not matter since its future posiiton can be easily calculated for any time. A telescope monitors the theoretical position of the ship, watching for any future burns. Whereupon the new trajectory is calculated.
The point is that there are no military strategic surprises. The enemy knows exactly where every one of your ships are, and when they will arrive at their destinations.
Nightrider's top secret gravity drive will change all that. It will allow the ship to make changes in trajectory invisibly, without any bright fusion plumes. Ships so equipped can thrust with fusion drives, the enemy will calculate the future trajectory, the ship will sneakily change their course with the gravity drive, and the enemy will have a rude surprise when you ship appears at an unexpected location. The drive can only accelerate Nightrider 0.25g, but that is plenty. Since it is a reactionless drive, low thrust is not a problem.
Alas, in reality, this won't work. Because there ain't no stealth in space. Specifically because even though there is no brilliant fusion drive plume, the gigawatt fusion reactor powering the gravity drive will emit enough megawatts of waste heat to be just as easily detected.
Be that as it may, the Nightrider is still very interesting in its internal arrangement of deck plans.
This is from material from the Fourth Symposium on Advanced Propulsion Concepts parts i, iii, iii and from Aerospace Project Review Issue Volume 1, Number 5. As always, in the datablocks you see in on the edges of this page the values in black are from the source documents but the values in yellow are not. Yellow values are ones that I have personally calculated, sometimes using questionable assumptions. Yellow values are not guaranteed to be accurate, use at your own risk.
In March of 1965 the Orion program was pretty much over. Nobody was interested in a spacecraft powered by hundreds of atom bombs. In a frantic attempt to keep it alive, General Atomic released a report describing several potential military applications. Hey, Pentagon, here are some great serving suggestions for an Orion! Please don't let the program die.
It didn't work but you can't blame them for trying.
|Pusher Diameter (m)||8||10||12|
|Exhaust Velocity (m/s)||26,700||32,400||36,000|
The applications used all three of the standard Orion engines: eight, ten, and twelve meter pusher plate sizes. Since a nuclear launch was pretty much out of the question, each proposal used a stage of quick-and-dirty solid rocket clusters to loft the Orion to an altitude of 76,200 meters before the nukes started. The liftoff thrust-to-weight (T/W) ratio was 1.8 for all three Orion sizes. The solid rockets got the spacecraft up to 76,200 meters and 2,900 m/sec, the Orion drive kicked it the rest of the way into a 370 km orbit. The back of my envelope says the Orion has to expend 8,300 m/s of delta-V, some of that is aerodynamic drag and gravity drag.
8-meter Orion spacecraft would be lofted by a cluster of seven 120-inch solid rocket boosters, developed from the strap-on solid rockets used on the Titan III launch vehicle. They would have been more powerful than the Space Shuttle solid rocket boosters.
10-meter Orion spacecraft would be lofted by a cluster of four 156-inch solid rocket boosters. These were studied in the 1960s as possible strap-ons for the Saturn V, and as a cluster to replace the first stage of the Saturn Ib.
12-meter Orion spacecraft would be lofted by a cluster of seven 156-inch solid rocket boosters.
When the Orion drive started up at 76,000 m, its T/W was only 0.55. This meant a very ugly gravity tax, but the total payload delivered to orbit was maximized. Who cares about gravity tax, the Orion has delta-V to spare.
From a military standpoint, the Orion drive is attractive not only because of its high thrust and specific impulse. The drive is also resistant to damage. Fussy delicate chemical engines can be disabled with a handgun. Orion drives are built to be tough enough to withstand hundreds of impacts by nuclear explosions at close proximity. A handgun bullet will just bounce off. The enemy will have to use massive weapons in order to dent one of those babies. This is not as big a selling point for NASA, who generally does not have to worry about enemy spacecraft taking pot-shots at them.
For the same reason such drives are very easy to maintain and repair. You don't need needle-nosed pliers and micro-screwdrivers. A sledge hammer and a cold chisel will do. It helps that the engine is made of good ol' simple to fix steel, instead of cantankerous titanium or aluminum.
And unlike nuclear thermal rockets, Orions have very low residual radioactivity. It is safe to go out and work on an Orion drive only a few minutes after the last nuke exploded. Nuclear thermal rockets on the other hand will be unsafe to go near for a few thousand years.
Some of the applications had the Orion spacecraft stationed in space, others had them based on the ground. The former was basically using the Orion drive to loft an outrageously huge military space station into permanent orbit, in one piece. Applications stationed in space could be launched at leisure. Applications stationed on the ground on the other hand were a reaction force. The Orions would sit in their silos "on alert", ready to launch at a moment's notice. For space based system the primary concern is maneuverability and survivability. For ground based systems the primary concern is readiness.
The minor drawback of the Orion spacecraft's titanic mass is there was no practical way to land them back on Terra (short of lithobraking). Once they were launched into space, they stayed there. The crew was rotated by space shuttles or small reentry vehicles. Trying to land under Orion drive power is a very bad idea, especially on a planet with an atmosphere. The ship will be entering the center of each raging nuclear fireball with lamentable results.
STATIONED IN SPACE
- Strategic Weapon Delivery ("Bomber")
- Space Defense
- Orbit Logistics
- Lunar Base Support
- Space Rescue and Recovery
- Satellite Support
- R&D Laboratory
STATIONED ON TERRA SURFACE
- Emergency Command/Control
- Space Interceptor
- Damage Assessment
- Space Rescue and Recovery
- Satellite Support
EMERGENCY COMMAND/CONTROL (ECCS)
|Stage 2 Orion Engine|
|Pusher dia||8 m|
|Exhaust Vel||26,700 m/s|
|Payload Mass||91,000 kg|
|Orion Engine Mass||82,000 kg|
|Dry Mass||172,700 kg|
|Pulse Units Mass||290,300 kg|
|Wet Mass||463,000 kg|
|Total ΔV||26,300 m/s|
|Reserve ΔV in LEO||18,000 m/s|
|Stage 1 Chemical Engine|
|Payload Mass||463,000 kg|
|Wet Mass||2,540,000 kg|
|Total ΔV||3,100 m/s|
|Stack Height||64 m|
|Stack Max Dia||9.1 m|
In case NORAD gets taken out by a dastardly nuclear first strike on the United States, the ECCS Orion was designed to survive in its secret armored launch silo. It would boost into orbit and take over NORAD's functions, coordinating the nuclear retaliation.
Actually the plan was to launch before the enemy bombs actually hit the ground. NORAD can probably predict it will be unlikely to survive an incoming nuclear strike long before the bombs actually arrive.
The ECCS was housed in an 8-meter Orion. The surface geometry was smooth to avoid creating shot-traps, since an enemy would target an ECCS with lots of hostile weapons fire. After expending all those extra nukes to obliterate NORAD the enemy will be obligated to destroy all the ECCS NORAD-back-ups, otherwise they will have wasted all those warheads and have nothing to show for it.
Since the ECCS would operate beyond Terra's magnetosphere, the crew would need radiation shielding from galactic cosmic rays. Not to mention enemy nuclear warheads, possibly including enhanced radiation weapons.
The wet mass was 2,540,000 kg (5,600,000 lbs), of which 91,000 kg (200,000 lbs) was payload (apparently "payload" is the dry mass of the Orion spacecraft, without any nuclear pulse units. At least that's what my calculation suggest). Stack height with solid rocket boosters was 64 m (210 ft) (cluster of seven 120-inch solid rockets) and a maximum diameter of 9.1 m (30 ft). The boosters loft the Orion to an altitude of 76.2 km (250,000 ft). Then the 8-meter Orion engine uses its 2,400,000 N (530,000 lbf) of thrust and 2,750 seconds of Isp to get the rest of the way to a 370 km (200 nautical mile) circular orbit. At this point it would still have a delta-V reserve of 18,000 m/sec (60,000 ft/sec) for further maneuvers. The reserve can be used to provide orbit altitude and plane changes to provide the most effective surveillance coverage and to evade hostile weapon interceptions.
The ECCS will require a silo only slightly larger than a standard ATLAS or TITAN ICBM silo.
The ECCS would carry a crew of from ten to twenty, with lots of advanced surveillance and communication equipment. Average mission was 30 days, with provisions for up to 60 days. Radiation shielding on the order of 244 kg/m2 (50 lb/ft2) would be around all command/control and crew operating station, to protect against galactic cosmic rays and possible hostile enhanced radiation weapons. The structure, life support systems, and attitude jet fuel will provide an additional 244 kg/m2 for a total of 488 kg/m2 (100 lb/ft2). By way of comparison, a storm cellar protecting the crew from a significant solar storm should have at least 5,000 kg/m2.
Several ECCS would be on constant standby in their silos. If nuclear war was immanent one would be launched as a show of force, demonstrating that the US was "not unprepared to defend itself." Along with a diplomatic reminder that there are more ECCS where that came from.
One would NOT be launched if it was only a time of crisis instead of immanent war. That would be provocative, and could precipitate matters. It is difficult to convince the enemy to stand down from DEFCON 2 when you are massing troops on their boarder, so to speak.
Deployed in low orbit allows immediate surveillance coverage of enemy territory and maximum image resolution. Deployed in remote orbits provides broader coverage of the planet's surface and also allows early warning of incoming hostile weapons fire aimed at the ECCS.
|Stage 2 Orion Engine|
|Pusher dia||10 m|
|Exhaust Vel||32,900 m/s|
|Payload Mass||136,000 kg|
|Orion Engine Mass||110,000 kg|
|Dry Mass||246,000 kg|
|Pulse Units Mass||354,000 kg|
|Wet Mass||600,000 kg|
|Total ΔV||29,300 m/s|
|Reserve ΔV in LEO||21,000 m/s|
|Stage 1 Chemical Engine|
|Exhaust Vel||2,880 m/s|
|Payload Mass||600,000 kg|
|Engine Mass||936,000 kg|
|Dry Mass||1,536,000 kg|
|Propellant Mass||2,964,000 kg|
|Wet Mass||4,500,000 kg|
|Total ΔV||3,100 m/s|
|Stack Height||96 m|
|Stack Max Dia||10 m|
Three of these would be placed in geosynchronous orbit to provide constant global surveillance. They would augment their coverage via inter-ship relay. This will allow the ships to randomly change their positions and frustrate enemy weapons interceptions, yet still maintain coverage. One ship will be the "flagship" but others could take over if the flagship is disabled.
The wet mass was 4,500,000 kg (10,000,000 lbs), of which 136,000 kg (300,000 lb) was payload. Stack height with the stage 1 solid rocket boosters was 320 feet (cluster of four 156-inch solid rockets) and a maximum diameter of 96 m (33 ft). The solid rocket booster has a mass of 3,900,000 kg (8,500,000 lbs). At an altitude of 76.2 km (250,000 ft) the 10-meter Orion engine uses its 3,500,000 N (780,000 lbf) of thrust and 3,300 seconds of Isp to get the rest of the way to a 42,162 km (22,766 nautical mile) geosynchronous orbit. At this point it would still have a delta-V reserve of 21,000 m/s (70,000 ft/sec) for further maneuvers, though in theory it is in its forever home.
Actually, since the SSCCS will be launched in leisurely times of peace instead of under the urgent pressures of impending nuclear armageddon, solid rocket boosters are not needed. Instead the more sophisticated (but more time consuming) liquid-fueled Saturn V's S-IC stage could be used. Especially if NASA ever manged to make the S-IC recoverable, which as SpaceX has demonstrated drastically lowers the launch cost. Such a stack would have a wet mass of 3,300,000 kg (7,200,000 lbs).
The SSCCS will require about 3 megawatts with a peak of 9 MW or so for the surveillance and communication systems. This can be provided with RTG or other advanced power source. The crew will number from 20 to 30, with six-month tours of duty. The SSCCS will stay on location for their operational lifetimes, 15 to 20 years. The long lifetimes are due to the fact that upgrading obsolete surveillance and comm systems is a snap when you are using Orion drive cargo ships. No matter how much the replacements weigh. The communication/surveillance section is basically a chassis accepting plug-in replaceable modules.
STRATEGIC WEAPON DELIVERY (SSSWD or "Bomber")
|Stage 2 Orion Engine|
|Pusher dia||12 m|
|Exhaust Vel||36,000 m/s|
|Payload Mass||136,000 kg|
|Orion Engine Mass||170,000 kg|
|Dry Mass||306,000 kg|
|Pulse Units Mass||424,000 kg|
|Wet Mass||730,000 kg|
|Total ΔV||31,300 m/s|
|Reserve ΔV in LEO||23,000 m/s|
|Stage 1 Chemical Engine|
|Payload Mass||730,000 kg|
|Wet Mass||6,800,000 kg|
|Total ΔV||3,100 m/s|
|Stack Height||88 m|
|Stack Max Dia||12 m|
This would require a full blown 12-meter Orion engine, because nuclear missiles are very heavy. And because you want to carry as many as you possibly can.
The wet mass was 6,800,000 kg (15,000,000 lbs), of which 136,000 kg (300,000 lbs) was payload. Stack height with the solid rocket boosters was 88 m (290 ft) (cluster of seven 156-inch solid rockets). At an altitude of 76.2 km (250,000 ft) and a speed of 3,100 m/s (10,000 ft/sec) the 12-meter Orion engine uses its 4,300,000 N (970,000 lbf) of thrust and 3,670 seconds of Isp to get the rest of the way to its patrol orbit. At this point it would still have a delta-V reserve of 23,000 m/s (75,000 ft/sec) for further maneuvers.
- At A the SSSWD boosts into LEO (370 km) with solid rockets and Orion drive. The crew does a systems checkout.
- At B burns into a Hohmann transfer (blue arc)
- At transfer apogee C it burns to circularize the orbit. SSSWD is now in a 190,000 km circular orbit (green circle)
- At D burns to enter Patrol orbit (red ellipse). Orbit has a perigee of 190,000 km and apogee of 410,000 km (a 190,000-410,000 km Terran orbit). The orbital period is 18.9 days
The crew will number 20 or more. A semi-closed ecological system will be used to permit a six-month tour of duty, with an emergency capacity of one year. It would require about 1 megawatt of onboard power for ship systems.
The interesting details about the weapons loadout are either not defined or classified. They are not in the report at any rate. Drat!
Defensive weapons include decoys and antimissile weapons. Defensive weapons are carried because bombers are the enemy's prime targets. The enemy knows that every single strategic weapon a SSSWD carries is a mushroom cloud with their name on it.
The strategic nuclear weapons were to be carried internally to allow easy access for maintenance. That way the technician wouldn't have to wear a space suit. The weapons are probably either megaton-range "city-killer" nukes, or MIRVs of deci-megaton-range. For reference, the original Minuteman-II ICBM carried a 1.2 megaton W56 thermonuclear warhead. The Minuteman-III had a MIRV bus carrying three 0.17 megaton W62 thermonuclear warheads (170 kilotons). Scott Lowther's recreation of the SSSWD carries 25 MIRVs, each with three warheads.
The nukes could be launched in either of two ways.  warheads could be mounted on missiles, launched from deep space, and guided to their targets.  the Orion bomber could use its 23,000 m/s of delta-V to enter a close hyperbolic flyby of Terra and release the warheads when near Terra.
On the one hand, the first option means the Orion does not have to get close to the target and be exposed to hostile weapons fire. On the other hand the missiles will have very limited delta-V because you cannot cram a full sized ICBM into the Orion bomber. True, the missiles will start with the Orion's orbital velocity but still. Since the paper cites enemy interceptor missiles requiring a day or two to reach the Orion bomber, presumably any missile the SSSWD launched will require a similar amount of time to reach the enemy cities.
The second option means the Orion bomber has to go into harms way. The up side is it can use its awesome amount of delta-V to deliver the MIRVs ballistically. And it probably can deliver the warheads to the target much quicker than any missile. One can just imagine the enemy generals freaking out at the sight of a three-hundred-ton spacegoing ICBM-farm dive-bombing you at hyperbolic speeds on a trail of freaking nuclear explosions while machine-gunning your continent with city-killer nukes.
According to the paper, a fleet of about 20 spacecraft would be deployed. Presumably this will ensure that there will always be several bombers close enough so that the MIRVs travel time will be short enough to give the enemy a major strategic problem. If my slide-rule is not lying to me, a 190,000 km-410,000 km orbit has an orbital period of 1,635,282 seconds or 18.9 days. With 20 SSSWD evenly spaced, that would have a bomber passing through perigee every 81,764 seconds or every 22.7 hours. I picked 410,000 km as a nice round value "beyond Luna" since the report did not give a precise figure. They might have selected an apogree figure to make a bomber pass through perigee once a day.
Siteing strategic nuclear weapons in deep space would be a major escalation of the nuclear arms race. Such Orion bombers are much more difficult to attack, compared to ICBMs in silos or nuclear submarines. It would require entirely new strategic planning and weapons systems. The high orbits mean that enemy weapons would require a day or more to reach the orbiting Orion bombers. If the enemy wishes to take out the Orion bombers simultaneously with the US ICBM silos and nuclear missle submarines, they will be forced to give the US a day or more of warning time. This sort of spoils the surprise of a first strike. In addition the long warning gives the Orion bombers ample time to take evasive action and/or deploy decoys and antimissile weapons.
On the minus side, such a drastic escalation may panic the enemy into starting a nuclear war before the Orion Bomber network was fully established. If the enemy is only half-panicked, they will probably start a crash-priority project to make their own Orion bomber network.
|Wet Mass||3,629 tonnes|
(4,000 short tons)
effec: 3,600 sec
|Detonation delay||1.1 sec|
|1.25 g||1.25 g|
|Missiles Silos||3 banks of 30 each|
When the Orion nuclear pulse propulsion concept was being developed, the researchers at General Atomic were interested in an interplanetary research vessel. But the US Air Force was not. They thought the 4,000 ton version of the Orion would be rightsized for an interplanetary warship, armed to the teeth.
And when they said armed, they meant ARMED. It had enough nuclear bombs to devastate an entire continent (500 twenty-megaton city-killer warheads), 5-inch Naval cannon turrets, six hypersonic landing boats, and several hundred of the dreaded Casaba Howitzer weapons — which are basically ray guns that shoot nuclear flame (the technical term is "nuclear shaped charge").
This basically a 4,000 ton Orion with the entire payload shell jam-packed with as many weapons as they could possibly stuff inside.
Keep in mind that this is a realistic design. It could actually be built.
The developers made a scale model of this version, which in hindsight was a big mistake. It had so many weapons on it that it horrified President Kennedy, and helped lead to the cancellation of the entire Orion project. The model (which was the size of a Chevrolet Corvette) was apparently destroyed, and no drawings, specifications or photos have come to light.
Scott Lowther has painstakingly done the research to recreate this monster. If you want all the details, run, do not walk, and purchase a copy of Aerospace Projects Review vol2, number 2. He also made a model kit of the battleship for Fantastic Plastic, you can order one here.
Rhys Taylor is a scientist who is also a master of the 3D modeling package Blender. His animation of a launching Orion drive spacecraft is quite famous, and has been seen by most people who type "Orion" into Google. His more recent project is a battle between US and Russian Orion drive ships out around Jupiter, and a rendition of the proposed Orion Discovery from preproduction of 2001 A Space Odyssey.