That Buck Rogers Stuff

Other cool links:

Here is another, more detailed, story on the robot from the National Defense Magazine.

Globalsecurity.org has pages for MDARS and a related project, REDCAR.

And of course, you absolutely must check this out.

The Titanians have built a respectable space navy, with a core of Orion drive battleships, and a larger number of smaller conventional nuclear thermal drive commerce raiding corvettes and frigates.  As diplomacy falters, an unfortunate incident involving a Europan revenue cutter and a Titanian-flagged merchant solar sailship inbound to circum Mars provides the pretext for war.  Europan merchant vessels are spread throughout the system, carrying almost a third of all shipping.  Most of these are slow, automated solar sail freighters, but others span the spectrum of commercial ship design.  The Titanian navy deploys many of its commerce raiders downsystem to strangle the Europan economy. 

The Europan main battle fleet is not currently circum-Jove, as it recently moved forward to the Trojan belt to overawe the piratical kingdoms located amongst the asteroids clustered 60 degrees ahead of Jupiter in its orbit.  What remains in Jupiter space is the smaller home fleet and a gaggle of small warships.

Due to the alignment of the planets (something that the Titanian high command was certainly paying attention to) there is a favorable transit from Saturn to Jupiter, as Jove is overtaking Saturn, being located in an inward and thus faster orbit.  The Titanian fleet is in an excellent position to quickly drop down on Jupiter, while the Europan fleet is nearly a quarter of the way around the sun and ahead of both Jupiter and Saturn.  It will be difficult for them to make it into battle in time.

The Europan home fleet can not refuse battle, because that would leave their moon open to attack.  But though the quality of their crews is unparalleled, the Titanian fleet slightly outnumbers the Europans.  Europan planners feel that it is a nearly even match.  But tactical considerations favor the Titanians.  As they will be decelerating into the Jupiter space, their heavy pusher plates will be facing toward the Europans.  This provides maximum protection to the Titanian battleships, and allows uninterrupted X-ray laser fire as the battle is joined.  Contrariwise, the Europans must perforce be accelerating towards the incoming fleet, and their pusher plates will generally be facing away.  Smart maneuvering will mitigate this somewhat, but the front of the ship remains the front of the ship.

The Europan Navy dispatches its corvettes and cutters outsystem, using a gravity whip maneuver that will disguise their eventual position.  They will coast up, powered down, and lie in wait for the enemy fleet.  Hopefully, they will inflict significant damage as the Titanians pass – but losses will be high as the ships reveal their positions by opening fire.  The Europans can be confident in the placement of these lurkers, because the location of the Titanian fleet is well known, and can only follow a narrow set of courses and still arrive at Jupiter.

The Titanian fleet powers on, occasionally launching a spread of sensor drones ahead in hopes of detecting enemy corvettes.  These drones are soon overtaken by the fleet as it accelerates towards battle.  The first combat occurs fifteen million miles out from Jupiter.  The furthest of the screen of corvettes avoids detection until within a quarter million miles of the fleet – less than the distance from the Earth to the Moon.  All of its X-ray laser missiles have been deployed, as have all of its sensors drones.  The resulting sensor net gives the ship a much better picture than the fast moving Titanian battlefleet.  All at once, the laser submunitions fire – each a small nuclear explosion pumping ten multi-gigawatt X-ray lasers.  Sixty lasers hit twelve targets, a spread determined by the sophisticated targeting computers on board the ESNS Gomer Pyle (the Europans have an odd sense of humor) and the instincts of her veteran gunners.  As much as possible, the gunners on the Pyle try to hit from the side, and avoid the thick refractory material of the pusher plate.  In this, they succeed somewhat – the more alert among the Titanian targets detected the Pyle in time to turn tail toward the enemy.  Nevertheless, the HRE Vindictiveness is completely disabled, and two others severely damaged.  Light damage on the remaining ships is soon made good.

For its trouble, the Pyle is quickly destroyed in a hail of laser and particle beam fire.  But the Europan command is pleased.

Over the next several hours, as the Titanian fleet slows as it backs into Jovian space, it endures several more attacks by lurking Europan cutters, corvettes and frigates.  One more battleship is destroyed, but the Titanians are now alert and wary, and destroy thirty Europan warships with long range massed laser fire.  Before the Europan home fleet can reach the Titanians, one more Titanian warship is hulled by a lucky long-range shot by a massdriver on the outer moon of Erinome. 

Now the home fleet has completed its swing around Jupiter, adding his gravity to their already impressive acceleration.  The fleet is moving toward the enemy.  But now, the admiral of the fleet faces the most crucial question in a space battle – what speed and course?  His decision now will likely determine the course of the battle; because as good as his gunners and drone controllers are, if he does not put them in the right place, their skills will be useless.  His options are limited.  He must prevent the Titanians from bombarding Europa and her orbital factories, shipyards and habitats.  If the Titanians maintain their present course, they will do just that.  So he must either destroy or deflect them…

The Orion drive will provide a (very expensive) platform for moving large amounts of men and materials quickly across interplanetary distances.  Ships built around less effective drives will be cheaper but much less capable than the Orions.  It seems unlikely that any private concern would, in the near future, have the resources or need to build Orion drive commercial ships.  Most private, and non-military government transport will use rockets, ion drives or solar sails.  Sails will be especially favored by private concerns because of the cheapness of operation � absolutely no fuel costs.  Faster transportation for VIPs or urgent cargos will be provided by souped up, stripped down nuclear thermal rocket powered craft.

If a power wishes to impede the shipping of a rival, non-Orion warships will be the most cost-effective commerce raiders.  These ships would operate like earthly submarines, and it would be well within their power to effectively attack enemy shipping, or engage in anti-�submarine� warfare.  Reconnaissance, intelligence gathering, lurking, stealthily inserting commandos � these are other missions that they might conduct.  They could even serve as a sort of destroyer screen for a force of more capable ships.  As escorts for friendly shipping, they would be useful in warding off the predations of enemy commerce raiders.  But these light warships would be less well suited to the other missions that a space navy would be called upon to fight. 

[wik] Side note: in talking about the relative usefulness of Orions and other warships, I am imagining a time when the solar system is somewhat well settled, and rival powers have emerged, and space warfare has had time to evolve.  Initially, combat between the smaller classes of warships would be the leading edge � until the first Orion warship is built.  I think that the first Orion would be like the British Dreadnought, taking naval warfare to an entirely different level, and possible igniting an arms race.  The first interplanetary warships will be commercial or government ships originally designed for other purposes and retrofitted with weaponry.  Indeed, ships like that will still be part of navies for a long time after the first purpose-built warships are laid down.  But eventually, someone will become sufficiently frustrated with the limitations of conventional ships, and build that first Orion.

Battleship or Carrier?

Since we�ve been so free with analogies to naval warfare, let�s throw out a few more.  If the smaller class of warships, using conventional drives, are to be likened to submarines, what is the proper analogy for the Orion drive warships?  The obvious choices are Aircraft Carriers and Battleships.  Which one it ends up being depends a lot on weapons technology.

On earth, the battleship was surpassed by the carrier because of the advantages of aircraft.  The best carrier without its dive-bombers, fighters, and torpedo planes would be a sitting duck for even an awkward, adolescent battleship.  Why did aircraft have such advantages?  Speed and range.  Battleships were not only the largest of warships, they were the fastest and longest ranging.  Aircraft trumped that by being able to fly above the water at speeds ten times or more faster than the fastest ship, and then drop bombs on the battleship with impunity from thousands of feet up.

Can we imagine an analogous vehicle in space?  We have already seen that an Orion powered ship will be faster and have longer range than any smaller ship.  While an Orion-powered ship could indeed carry fighter-equivalent spacecraft, dispersing your firepower into a bevy of smaller and slower ships does not seem to be as great an advantage as it was for wet navies.  The same logic that drove the development of ever larger, ever more heavily armed battleships seems to apply to spaceships as well.

However, another consideration might yet result in Orion carriers rather than Orion battleships.  The development of autonomous reconnaissance and (very soon) combat drones is well under way.  There is no reason to believe that these developments will not be carried into space � in fact, all of our robotic space probes could be considered non-combat autonomous drones.  The advantages of a non-crewed warship would be many � greater tolerance for acceleration, no need to waste mass on life support and a vulnerable but clever meatsack, and less concern if the drone is lost as opposed to a piloted warship.  I don�t think that the big warships will ever be unmanned, as the limitations placed on communications by the speed of light will require that humans be present at the battlefield.  But that does not mean that drones will not be present on the battlefield.  As I mentioned earlier, the line between weapon, sensor, and drone will grow vague.  Each ship will be attended by a network of drones, feeding sensor data back to the mother ship; and if opportunity presents - deploying itself as a weapon.  A big part of battle management will be the handling of these networks of drones.  (I think that will be true here on earth in a very short time as well.) But these drones � be they weapons platforms akin to fighters, sensor drones, or x-ray lasers, will not make the Orion warship into a carrier.  The primary focus will I think remain on the primary weaponry of the warship; if only because the autonomous drones of various types could never keep up with the mother ship.  It does not pay to deploy millions of dollars of equipment that could be rapidly left behind by a fast moving battle, and play absolutely no part in the battle itself.

So the Orions will be battleships, queens of space.  The generous payloads of Orions will likely see them armed with powerful generators, lasers and masers, particle beam weapons, railguns and metalstorm cannon.  Bundles of lasing rods like those used in the standoff X-ray lasers could be dropped overboard with propulsion nukes, literally gaining more bang for the buck.  The powerful weaponry of an Orion battleship, powered by an onboard fission reactor, would likely outrange as well as outpower any smaller ship.  (Just like with traditional battelships, which could shoot farther than any other.) Armor will be possible, making the battleship resistant to many of the weapons capable of being carried by smaller warships, and even to those mounted on orbital bases.  (An Orion battleship is in effect a mobile base � considering its size.) Crew complement for an Orion Battleship might number in the hundreds � mostly for damage control, but also to manage all the weapons, sensors, drones and communications that would be required by such a vessel.

Next bit will cover what might happen in an actual space battle.

[also wik] Side note: The only reasonable variant on the basic battleship that seems likely is an assault version.  It would perform the traditional naval missions of projection of force and covering assaults.  This vessel would be used to rapidly transport space marines and the means to get them into whatever they�re attacking � winged landing craft, zero-gravity assault boats, or whatever is required.  This type of ship would also favor the types of weapons that could be used to bombard planetary surfaces.  In time, as space navies build more Orions, variations in size and relative power might eventually be grouped into traditional categories such as frigates, cruisers and battleships.  Or we might come up with altogether new names.

[also also wik] I think that in the long run, the traditions of the Navy will be more suited to space warfare than those of the Air Force.  But since the Air Force is closer to space - they will likely get there first.  And we’ll have generals in command of our space fleets.  And that would suck.

Gunboats operating in orbital space around, say, Earth will have powerful, high thrust engines and limited facilities for life support.  They will be based in orbital forts, or perhaps launched atop disposable launch vehicles like the Gemini or Apollo rockets of the sixties.  The life of the crews of these warships will be more like that of an Air Force fighter pilot than that of a submariner � which I think will be the closest analog for long duration deep space warships.

Gunboats, operating in the constrained space around a planet, will engage at shorter distances than their deep space cousins.  In most respects, their armament and sensors will be very like that of a modern jet fighter.  In fact, they will probably look something like a modern fighter � as being able to enter the atmosphere (at least the upper reaches of it) will be a very useful thing.  Aero-braking, skip-jumping along the top of the atmosphere, and similar tactics will all save fuel while increasing the range and maneuverability of the ship.  And being able to land on Earth will be a happy alternative to dying in space in the event of damage to the ship.

Looking beyond the descendents of a marriage between the space shuttle and an F-15, other types of orbital gunboat can be imagined.  Light sail ships, boosted by ground or space based lasers might also be developed.  Heavier warships, analogous to coast guard cutters might linger in orbit for weeks at a time, before returning to base.  If scramjets are ever perfected, then warships operating at the interface between space and the atmosphere might become common.  All of these types would have some capacity to attack targets on the ground, and in fact some might be designed around that mission.  Erwin Sanger, an Austrian designer in the forties, imagined a rocket-powered bomber that would skip along the top of the atmosphere.

In combat within the gravity well of a large planet, altitude will be the most important tactical consideration.  Like the wind gauge for sail-powered warships, gravity gauge will be the dominant factor.  Having the advantage of position will be crucial, in that a position higher up the gravity well translates to more options for maneuver.  Also, shooting up the gravity well is inherently harder than shooting down.  The first pilots of these warships will have to learn the somewhat paradoxical logic of orbital mechanics � slowing down speeds you up, and vice versa.  For pilots used to the straightforward maneuvers within an atmosphere will have to adapt quickly. 

Deep Space Design Tradeoffs

Deep space will offer vastly different challenges to warship designers.  All of the propulsion systems that might be available in the near future have serious limitations.  Two tradeoffs will determine the design of all warships.  The first is mass/acceleration; the second is power/stealth.  I noted in the first part the tradeoffs required by stealth.  Most of the tradeoffs for mass and acceleration will push ship design in the same direction.

The major propulsion systems that could be constructed with current or very near future technology are chemical rockets, nuclear fission rockets, nuclear pulse drives, ion drives and solar sails.  The first three are high thrust, short duration drives; while the last two are low thrust, long duration.  With the exception of nuclear pulse, which I will discuss separately, all of these systems impose the same limitation on warship design: every ounce of mass will reduce the total acceleration the warship is capable of.  Space types refer to this as delta-v, or change in velocity.  It is a measure of the total change in velocity (speed plus direction) that the ship is capable of with a given drive and fuel supply.  It doesn�t matter whether your ship accelerates really fast and then coasts, or if it makes a long slow burn, since delta-v measures the total change.  This makes it a useful comparison between ships even of vastly different design. 

(While solar sails will have effectively infinite delta-v, because they use the solar wind for propulsion, solar sails will not be well suited for combat since the sails are so visible and so fragile.  Warships will be confined to the other drives.)

Ship designers will always be striving to make the ship lighter.  This will allow engines of a given capacity to achieve a higher delta-v.  However, there are things that a warship must have in order to be effective.  Weapons, armor, sensors and stealthing; crew, and food, water and life support for voyages lasting months or more; a storm cellar to protect the crew from solar flares; fuel or reaction mass; these are all things you will need to bring along.  Rockets and ion drives are low energy, and this balance will place a premium on low mass weapons, small crews (and thus lessened life support requirements) and little or no armor.

Weapons that require vast power plants will be right out.  (Both for mass and heat/stealth loss reasons.) Weapons that are themselves heavy will be right out.  Missiles will not be very useful in long-range engagements, due to the fact that a rocket capable of propelling a warhead to a target tens of thousands of miles away in time to affect a battle will be almost as large as a small space ship.  This would seem to put a premium on beam weapons.  However, as we discussed in the previous part, and as Clueless mentioned, power plants capable of powering lasers, masers, and particle beam weapons will be heavy and produce lots of heat.

So, it may very well be that early spaceships will be armed with rapid-fire cannon and machineguns.  With some effort, a high velocity, rapid-fire cannon could be developed for use in spaceships.  Rate of fire would be important, as I discussed in the first part.  The more rounds put in the general vicinity of the target will increase the chance of a hit.  One of the most promising technologies is the Metalstorm system invented by the Australian O�Dwyer.  This system stacks bullets in the barrel, and fires them electronically.  By bundling several barrels together, it can achieve rates of fire approaching millions of rounds per minute.  Gunners on warships would fire hundreds of rounds at a time, laying patterns that would (hopefully) intersect the course of the target.  Variations might include sub-munitions, target seeking or sensor rounds, and explosive rounds.  After firing all its rounds, individual Metalstorm units could be discarded, increasing available delta-v.  Rapid-fire, self contained, requiring effectively no external power, and disposable after use � Metalstorm cannon seem an ideal fit for spaceships.

As technology advances, smaller and more efficient power plants will allow warships to move toward beam weapons that will be more accurate than the cannon described above.  Unless radically better drives are developed, missiles will remain the weapons of orbital gunboats, and not deep space navies.  The mass penalty for missiles with adequate range will simply be too great.  Warships of these types will be armed with cannon; and, if they can be developed, standoff x-ray lasers. 

Deep space warships built around rockets or ion drives will tend toward small.  Small is better for mass and stealth both.  In all likelihood, they will be narrow, to provide a smaller radar and IR signature for enemies to detect.  (That is, as long as the ship is pointing in the right direction.) They will be covered with stealth materials, and the rear of the ship will have complicated and fragile fractal heat radiators as well as the drive exhaust.  Weapons will be concealed beneath the stealth covering.  Life for the crew will be hard, living in cramped spaces for months at a time.  I imagine it will be rather like a submarine.

Orion Drive

The exception to much of the mass considerations discussed above is the nuclear pulse, or Orion drive.  This concept involves building a very large ship with a heavy base plate attached to the back of the ship by some very serious shock absorbers.  Then, you light off a small nuke behind the ship.  Repeat as necessary.  This is an over-the-top propulsion scheme.  With this, you could accelerate very large masses very quickly.  Ships using an Orion drive would simply have to be big just to make the acceleration survivable.  Since you need a big ship; adding armor, huge power plants, or anything else you want is not such a big deal.  An Orion powered warship would be a huge hulking brute.  It would not be subtle, and stealth would be a lost cause. 

No other type of spaceship (based on current technology) could match the Orion for speed and payload.  It will be in a class by itself until and unless someone invents fusion or antimatter drives.  Meanwhile, the inherent limitations of the other propulsion types will limit the kinds of warships that can be built around them.  (As will the existence of Orion powered warships.) And given the requirement for (large numbers of) nuclear devices for propulsion in an Orion, and the stupendous expense of putting that much mass in orbit will probably mean that only governments will ever have them. 

Life for a crewman on an Orion warship will be easy, by comparison.  The generous payloads of an Orion will make for more comfortable quarters, and better life support.  Large amounts of armor will likely contribute to the peace of mind of the crew as well.  Rotating crew quarters providing artificial gravity might even be possible.  The speed of Orion will also mean shorter journeys � weeks instead of months between planets.

In the next part, we�ll look at strategic considerations, and how these ships might be employed.