Newtonian Space Combat

[Ariphaos]

This is totally possible. It's a simple matter of vectors. If you thrust a port-aft turning jet, and a starbaord-forward jet, then you'll spin really without shifting your course any noticible amount.

Why use thrusters for rotation instead of gyros?

[Sea Skimmer]

Why use thrusters for rotation instead of gyros?

Because a gyro is a form of motion sensor, not a propulsion device.

[phongn]

Because a gyro is a form of motion sensor, not a propulsion device.

You can use a large gyroscope for rotation, however. The ISS and HST use them to keep aligned without wasting fuel.

[Admiral Valdemar]

Gyros are bulky though and not something you really want in a combat vessel, especially if they take one too many bumps. They may mean no using of propellant, but that's an advantage you'd probably not be too concerned about in such a mission anyway.

[Nephtys]

If you've got a high-mass spacecraft and efficient propulsion technologies required for any kind of intra-system flight, fuel really ought to be a non-issue for maneuvering.

[Admiral Valdemar]

Plus, you'd probably take up too valuable space by having a central gyro array in the centre.

[Ariphaos]

Because a gyro is a form of motion sensor, not a propulsion device.

I find this amusing since I helped make test software for several hundred thousand such RLGs at my previous job :-p Nifty things, could not only measure the rotation of the Earth, but one could be made to measure the orbit around the Sun.

Regardless, since we are talking about such high-efficiency thrust, wouldn't it stand to reason that as materials with greater tensile strength developed, faster flywheel/gyro/free spinning gimballs would become less bulky, have multiple uses (potential source of spare power, weapon systems around a spherical craft not tied to the orientation of the craft and so on)?

[drachefly]

Plus, you'd probably take up too valuable space by having a central gyro array in the centre.

Gyro arrays do not need to be centrally located. Not that I think relying exclusively on gyros is a fabulous idea unless there are some startling advances in materials science.

[Admiral Valdemar]

To be efficient, they'd be best placed in the centre though. But I wouldn't want such a system in a combat vessel anyway unless it was going to be in orbit monitoring via stealth rather than fighting or patrolling.

[Ariphaos]

Gyro arrays do not need to be centrally located. Not that I think relying exclusively on gyros is a fabulous idea unless there are some startling advances in materials science.

Well you wouldn't, but while we're talking about plasma or similar thrusters capable of sustaining 1-3G accelleration for trips to Neptune and back, materials and mechanical science are not going to remain completely idle.

Also, there may be fundamentally different means of constructing and using gyros in such a manner.

[drachefly]

Well, what are the limiting factors on the capability of gyros? Tensile strength of material, size of gyro, mass of gyro. That's about it. I'm not seeing terribly much room for any material made from ordinary matter to have too much more tensile strength than carbon nanotubes. But they are light and thus make lousy gyroscopes.

Meanwhile, our thrust capabilities do have a lot more room for improvement. LOTS more room for improvement.

I guess it's kind of how I don't see future powers coming up with improvements on the wheel or inclined plane, but sure they can make a better power plant.

[Ariphaos]

Well, what are the limiting factors on the capability of gyros? Tensile strength of material, size of gyro, mass of gyro. That's about it. I'm not seeing terribly much room for any material made from ordinary matter to have too much more tensile strength than carbon nanotubes. But they are light and thus make lousy gyroscopes.

It's theoretically possible to make nets instead of tubes, and have them weighted down, or just spin them that much faster. Carbon chains a la =C=C=C=C=... are also theoretically possible, and would have greater tensile strength than nanotubes, though I'm not aware by how much. In terms of what is feasible in a vacuum that would be the limit.

If plasma shields are feasible, then they will have to be magnetically bound, and thus movable around the vessel. This kind of combination thruster-shield-'gyro' would be pretty neat.

[Sea Skimmer]

You can use a large gyroscope for rotation, however. The ISS and HST use them to keep aligned without wasting fuel.

I did not know that. However, the idea of a giant spinning mass onboard a warship is poor at best. If it were damaged, the result would easily be catastrophic, lets not forget what happens when a jet engine throws a blade.

[Admiral Valdemar]

That's exactly why I'd oppose it on a warship too unless it was simply a military surveillance vessel away from combat on high-endurance missions loitering in orbit. If you want stealth, the cold-thrust proposals I put forward are good as any, but you can never be totally invisible.

[Ariphaos]

I did not know that. However, the idea of a giant spinning mass onboard a warship is poor at best. If it were damaged, the result would easily be catastrophic, lets not forget what happens when a jet engine throws a blade.

Damaged?

Getting hit == dead. At the levels of energy we're speaking of, railguns are going to be launching projectiles at significant fractions of c, and lasers will be putting out similar levels of energy.

[Arrow]

Damaged?

Getting hit == dead. At the levels of energy we're speaking of, railguns are going to be launching projectiles at significant fractions of c, and lasers will be putting out similar levels of energy.

"Damaged" also includes shipboard accidents and material failure, not just weapon hits.

[drachefly]

Well, what are the limiting factors on the capability of gyros? Tensile strength of material, size of gyro, mass of gyro. That's about it. I'm not seeing terribly much room for any material made from ordinary matter to have too much more tensile strength than carbon nanotubes. But they are light and thus make lousy gyroscopes.

It's theoretically possible to make nets instead of tubes, and have them weighted down, or just spin them that much faster. Carbon chains a la =C=C=C=C=... are also theoretically possible, and would have greater tensile strength than nanotubes, though I'm not aware by how much. In terms of what is feasible in a vacuum that would be the limit.

I think the C=C=C=C chain would reduce very easily with either oxygen or hydrogen. Either reduction would drastically reduce the strength. Not exactly what I want my flywheel to be made of, so we had better have an atomically perfect vacuum pump (none exists) holding that stuff clean from fabrication to use. And heaven help you if it gets cracked.

Nanotubes don't fall apart if they meet H2, and even O2 isn't a problem at temperatures less than around 450 Celsius.

[Sea Skimmer]

Damaged?

Getting hit == dead. At the levels of energy we're speaking of, railguns are going to be launching projectiles at significant fractions of c, and lasers will be putting out similar levels of energy.

The same thing was said about planes in the age of missiles, it didn't turn out true then and fractional C railguns are pure wank. Not gonna happen.

[Nephtys]

Not at signifigant fractions of C. A more realistic reason is that a spaceship just cannot mount high-density armor and expect to be mobile without massive, massive leaps in propulsion technology. And bigger weapons are a lot simpler than advances in materials, propulsion and so on, which would also result in even more powerful weapons on the side.

[Admiral Valdemar]

Railguns doing several klicks/second are the norm and will get the job done with less energy expenditure. If you want a kinetic kick at near lightspeed, use a particle beam.

[Sea Skimmer]

Lasers to blind sensors and nuclear missiles to kill would probably be the normal combos. No need to get any more fancy then that

[Icehawk]

I dunno, couldnt you just use lasers to take out most missiles at long range in space? You would have to get a pretty big swarm I would think to overwhelm most ship defenses.

[Icehawk]

When I envision REAL space combat, I see ships thousands of klicks apart, blasting away at eachother with either high energy lasers to cross the distance instantly or with massive hypervolicity missile swarms or a large railcannon that can fire a round at atleast 1000+ km/s so that it will have a chance of actually getting to the target before they move out of the way or can shoot it down before it hits them.

In space you're going to want to keep as great a distance from your enemy as possible and so slow moving conventional missiles which take time to cross great distances and can easily be taken out by point defense lasers at range seem relatively pointless.

My ultimate personal space warship would, essentially be a large rail or laser cannon with engines and a large ammount of point defense weapon systems. The ship would be able to fire a slug at at least a thousand kilometers per second to kill just about anything it could ever want to and due to its heavy point defenses has an effective killzone at least in the hundreds of kilometers range in all directions for dealing with missile threats. You would have to super swarm it with missiles hypervelocity missles or fire a similar heavy weapon at it to have any real chance of taking it out.

[Nephtys]

I dunno, couldnt you just use lasers to take out most missiles at long range in space? You would have to get a pretty big swarm I would think to overwhelm most ship defenses.

At any range exceeding a few thousand klicks, a laser even is useless against something as maneuverable as a missile. Aiming one of them is not easy, especially with multiple targets on the way and lightspeed lag.

[Ariphaos]

Lasers to blind sensors and nuclear missiles to kill would probably be the normal combos. No need to get any more fancy then that

Nukes would be the sensor blinders, and lasers for the kill. A nuke exploding nearby would be extremely bright, several orders of magnitude brighter than the surface of the sun. Most of this light normally gets blocked due to the disintegration of the bomb itself and the irradiation of the surrounding atmosphere.

But there'd be nearly no pressure wave. Only temperature and radiation, most of which ships will have armoring against. And the flash would be extremely fast.