"Realistic" Space Combat/Travel Discussion Thread

[Skrim]

Space has no gravity or inertia...

I'm not reading you're post beyond this. You're talking out of your ass here. Learn physics and come back.

Space has gravity. All of spacetime has gravity. But it doesn't really matter in space combat unless you're fighting close to a planet/moon, in which case maneuvering would be a matter of changing orbits and the such. It matters a hell of a lot in space travel though, unless you're using an antimatter-driven torchship capable of using Brachistochrone trajectories. Torchships are out of the tech level we're talking about.

And ALL MASS has inertia. Regardless of where it is. You DO move backwards when you're ship accelerates forwards. So, please, SHUT UP until you know what you're saying.


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I'm not speaking of just cooling. Power consumption and whether or not they could actually track quickly enough to do damage to armored targets are also serious issues. Also, water ice would make for, as far as I know, a terrible coolant. It may work for terrestrial structures, but that's because replenishing coolant is as easy as having some more delivered. Space ships would often not have that luxury. Water is not very compressible at all. It also doesn't absorb all that much energy. I'm talking about coolants that have yet to be invented. Either a very fine particulate solid or some sort of gas would likely be best.

If you're using an advanced engineered cooling substance, then you'd probably be using some kind of very cold liquid, and you'd be using a closed-cycle system with heatsinks for combat and acceleration and droplet-type radiators while you're in transit or idle orbiting between missions. I for one, would not be venting expensive coolant into space.

For open cycle, I'd still prefer water/ice, because it's easily available(Saturn's rings, Kuiper Belt, ice asteroids, comets) and disposable - you can use it as propellant for NTR propulsion or vent it into space if you're heatsink is full and you don't have the time to deploy your radiators and sit around.

I'm not convinced that radiators would be very effective. They would work, but slowly. Again, armoring them would be terribly difficult (at least by today's standards. I could be way off here, please correct me if so). Because they need to have as high a surface area as possible, they're going to be pretty fragile. Lasers could just melt the shit out of them unopposed. Yeah, it'd be a good idea to have them, but a fully integrated coolant system is all but required. That means LOTS of coolant, or some way to produce it on ship (plant based? I can hardly speculate).

That's the thing. Radiators would be too slow and fragile for combat, so you'd be able to duel only until your heatsink fills up, after which you have to get away or die.
For civilian ships like explorers or freighters, radiators would be standard always-deployed and non-retractable. Like big wings, but not aerodynamic.

I've also been meaning to do some research on this, but have been pretty busy lately. Is it not possible that armor in the realistic near future might stand up to a nuclear explosion? I don't know. It would have to somehow spread the energy out. It's also worth noting that nukes in space are not as potent as those in an atmosphere. You don't get the pressure wave, which does a ton of damage.

I just remembered something.

It IS possible to stop nukes using armor.

It is the basis of Orion Drive.
Orion Drive uses a large heavily-armored pusher plate to deflect nuclear explosions out the back of the ship and move the ship forward with the gained kinetic energy.

So maybe, if a ship could be completely fitted with some kind of pusher-plate armor, it could stand up to nukes. Somewhat. Or if the ship is an Orion ship, they can turn their pusher-plate towards you're nukes and weather the attack. The nukes would push the ship away but that's a much smaller problem than taking a straight hit.

[ArcaneDude]

@Homer; Space has no FRICTION. That's why you don't need big ass thrusters to attain large speeds, though if you don't want to spend your entire lifetime accelerating I'd take a serious engine. Inertia is a different kettle of fish, since it's only dependant on mass, and so is gravity. There is mass in space, ergo there is gravity, albeit astronomically little in deep space.

[Dreamyr]

just a thought I had about armor. You guys are saying nano-carbon is the best you'll get and that you'd still need a crap ton of it to be effective thus slowing you down.

What about energized armor. you know, running a current through a material that when a certain type/frequency of energy is channeled through it it reinforces the bonds between the molecules making it tougher without weighing you down overly much.

Best example I can think of of this type of armor is the NX-01 from Startrek Enterprise.

Or is this kinda tech in the too far distant future?

[Homer]

What about energized armor. you know, running a current through a material that when a certain type/frequency of energy is channeled through it it reinforces the bonds between the molecules making it tougher without weighing you down overly much.

From what i know.. That wouldn't really work since you would eventually heat your armor to the point it melts or explodes. Also startrek just throws physics out the door. If you want to make armor stronger you get stronger armor. Now.. im kinda sure you can dampen energy weaponary with energy absorbing it but that would still hurt you.

Oh @skrim i meant friction not inertia

[jwa8402]

Or is this kinda tech in the too far distant future?

Whether its realistic or not, that specific instance was a result of lazy script writing.
My understanding of polarized hull plating is that it gives the usually ablative plates a positive charge that transfers to solid objects that impact it, which in turn repels or slows their impact. The current also attracts a cloud of particles which provides some radiation protection. How that blocks a freakin phaser, I don't know. It apparently drains a large amount of power so its not practical for very long. That was one explanation given in the show, but I don't know whether thats how it works in the real world.

I read about something called a whipple shield, does anyone know more about this? Apparently something we already have.

[Isu]

What about energized armor. you know, running a current through a material that when a certain type/frequency of energy is channeled through it it reinforces the bonds between the molecules making it tougher without weighing you down overly much.

From what i know.. That wouldn't really work since you would eventually heat your armor to the point it melts or explodes. Also startrek just throws physics out the door. If you want to make armor stronger you get stronger armor. Now.. im kinda sure you can dampen energy weaponary with energy absorbing it but that would still hurt you.

Oh @skrim i meant friction not inertia

um yes you can't believe any thing startrek tells you... it does tend to gag/bind physics in a very small, claustrophobic closet. The best advantage of energized armor would probably be your armor getting so hot that your ship turns into an amorphous blob of slag and projectiles pass right through it.

[Sponge]

I read about something called a whipple shield, does anyone know more about this? Apparently something we already have.

It's pretty much just a very thin sheet of solid material placed a bit in front of the hull it's protecting. When small objects moving at high velocities collide with it, it causes them to break apart and spread out. The resulting smaller fragments pose a much, much smaller threat. Not very viable for a space war, though. They're really just meant for micrometeorites.

[Skrim]

just a thought I had about armor. You guys are saying nano-carbon is the best you'll get and that you'd still need a crap ton of it to be effective thus slowing you down.

What about energized armor. you know, running a current through a material that when a certain type/frequency of energy is channeled through it it reinforces the bonds between the molecules making it tougher without weighing you down overly much.

Best example I can think of of this type of armor is the NX-01 from Startrek Enterprise.

Or is this kinda tech in the too far distant future?

Star Trek is completely unrelated to real-world physics.

On the topic of armor, nano-carbon probably won't be the best material out there. Given that nanoscale material sciences and tech are already underway and in use in some places(carbon fiber F-1 cars, etc.), I think we ought to have better nano-engineered materials as of the timeframe we are discussing - probably containing complex alloys and other stuff.
But MatSci is not my field of interest, so I don't know a whole ton about it.


As for energized armor, that IS a possibility. The British are already conducting research and trials on "electromagnetic reactive armor"(I'll call it EMRA), an energized armor for use on tanks and other war machines, designed to defeat shaped-charge missiles.
It basically uses a grounded outer plate of conducting metal seperated from an inner plate of the same metal, with an insulator in between. The inner plate is connected to a bank of supercapacitors, which is charged using power from the engine. When the enemy shaped charge hits, the focussed liquid-metal jet from the warhead effectively 'connects the circuit' causing a big current discharge flowing in the opposing direction of the penetrating jet. The discharge vaporizes and disperses the shaped charge, defeating it and protecting the tank.
Multi-layered EMRA could be theoretically employed to defeat tandem charges.

How effective EMRA would be against kinetic-energy APFSDS rounds, I don't know. In space, railguns/coilguns will be using high-density kinetic-energy penetrator rounds, not explosive shaped charges. So talking about EMRA for space combat is speculation at best.
And EMRA is no use against lasers.

[lemm]

Nuclear Warheads. You don't need anything else.



What I would like to know is how these ships are changing direction so quickly and so often... you can only carry so much rocket fuel!

[ArcaneDude]

The ships we're talking about don't use rocket fuel I believe, they rather use nuclear fission to power plasma or ion drives. All of these are existing technologies. That, and your Nuclear Warheads which-are-allegedly-all-you-need can be intercepted by laser point defense which is also an existing technology. Why do you believe modern day warships still carry cannons?

Just to back what I state;

http://news.bbc.co.uk/2/hi/technology/4527696.stm Article about succesfull ignition of a plasma drive.

http://www.space.com/businesstechnology ... 41119.html An article about a lunar satellite using an ion drive.

http://www.popsci.com/military-aviation ... ser-cannon An article about an airplane-mounted turreted laser cannon.

If anything, future combat spaceships *will* be armed with these things, albeit relatively light variants for point defence.

[Skrim]

Nuclear Warheads. You don't need anything else.



What I would like to know is how these ships are changing direction so quickly and so often... you can only carry so much rocket fuel!

It seems you are only taking present-day, nay, 1960s-era technology into account. Space combat will be very different from the Cold War.

Nukes will not be sufficient to cut it on their own.
Nuclear missiles would be too easy to intercept using laser point-defenses, and their guidance systems could be overwhelmed or jammed with ECM.
Even today, we're developing laser technology(the ABL and THEL projects) that can shoot down artillery shells and missiles, and here we're using primitive chemical lasers inside an atmosphere(which isn't exactly good for laser weapons). And even today, the AESA phased array radar emitters, used on warships and the latest generation of fighter aircraft, are capable of focusing their radar energy to disable missile guidance systems.


And, as ArcaneDude said, these ships will not be using pathetic chemical rockets. They'd be using magnetoplasma drives, bimodal nuclear-thermal or nuclear-pulse propulsion or maybe even fusion drives. Heck, we've already got interplanetary spacecraft(Dawn, Hayabusa, etc.) using ion drives, and magnetoplasma thrusters have already been ground-tested.

[Normandy]

Let's not forget though that the ion drives aren't particularly powerful (yet). They provide little more than a gentle push in the grand scheme of things.

Remember, every action requires an equal and opposite reaction, that's what these drives are based on. To make sharp turns and the like, you'd need to either expel particles at an incredibly high energy (I'm not too sure of the exact formulas behind this, but you're not exactly moving a craft of any significant weight using only a few milligrams of reaction mass), or expel a large mass of particles; i.e. a significant portion of the craft's weight.

[DeathsHands]

Well, it's safe to assume we're over a century in the future, so ion drives would've probably been sufficient by then. And you could always have chemical manouevreing thrusters; pretty much any other engine type that could accelerate quickly for 'em.

[Arcalane]

Well, it's safe to assume we're over a century in the future, so ion drives would've probably been sufficient by then. And you could always have chemical manouevreing thrusters; pretty much any other engine type that could accelerate quickly for 'em.

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