Space Laser and warfare

[ar81]

The problem is, in space you are always visible... :shifty:

Nope. You rely on sensors. If sensors can't see you, you are invisible.
Examples:

How many pieces of junk smaller than 1 meter are up there near geostationary orbit? How many particles of junk smaller than 10 cm are in LEO? NORAD can't see.

How many undiscovered asteroids are out there in the solar system?
Name the darker ones only.

Well, Orbiter can see everything... perhaps it is the all mighty probe...

 

[T.Neo]

The problem is that a military spacecraft is usually large (because of propellant and other systems) and hot (because of the power source, engines and crew).

Because you will always be hotter than the background of space, you will be detectable. And if you engage thrusters, you will stick out like a sore thumb- even attitude thrusters could be seen as far away as the asteroid belt.

There's a difference between operating spacecraft and dead rock. Of course the level of advancement of the sensors comes into effect, but suitably advanced ones should be expected for some sort of interplanetary warship...

There isn't any stealth in space. It might be possible to "hide" yourself from a certain field of view, but not in all directions. It mostly depends on attacking first, trying to mitigate/dodge weapon hits and having a large fleet so you can overwhelm the enemy.

 

[Izack]

Nope. You rely on sensors. If sensors can't see you, you are invisible.
Examples:

How many pieces of junk smaller than 1 meter are up there near geostationary orbit? How many particles of junk smaller than 10 cm are in LEO? NORAD can't see.

How many undiscovered asteroids are out there in the solar system?
Name the darker ones only.

Well, Orbiter can see everything... perhaps it is the all mighty probe...

Again you're using current figures in the context of an unforeseeable future.
Also, I thought everyone on this forum would know that there is absolutely no such thing as stealth in space. If it exists in the solar system, it can be seen by someone who wants to see it.

 

[Ark]

Perhaps there is no true stealth, but camouflage is always an option. Like placing an Earth-crossing asteroid between you and the enemy, or using the cover of a solar flare to advance on an enemy position.

 

[T.Neo]

I meant "hide" in terms of reduce the thermal signature of the craft.

A large thin shield would be placed between the ship and the enemy, and the ship would radiate waste heat at 90 degrees to the shield. The shield could be spectrally similar to an asteroid or cometary fragment, and thus be camoflaged as something "uninteresting".

It has limits, of course- if the enemy has sensors scattered around the solar system sufficiently, you'll be easily seen.

Another possibility is dazzling enemy vessels with lasers during a burn, so that they can't study your exhaust plume to see what sort of manouevre you are making.

 

[Kevon Daye]

A neutron bomb would allow you to capture an enemy ship more or less intact after killing the crew.

Actually, whole "killing all the people but leaving the infrastructure intact"thing is a bit of a misconception. Neutron bombs are more of a dirty bomb/conventional nuke hybrid.They typically have a relatively low yield (10-15kt), and throw out massive amounts of radiation, for such a low yield weapon.

 

[statickid]

Again you're using current figures in the context of an unforeseeable future.
Also, I thought everyone on this forum would know that there is absolutely no such thing as stealth in space. If it exists in the solar system, it can be seen by someone who wants to see it.

I've also heard that there is no such thing as screaming....in space..... :shifty:



*************************************

question: if an astronaut screams in space, and his com radio is off, does he actually make any sound?

 

[Izack]

question: if an astronaut screams in space, and his com radio is off, does he actually make any sound?[/QUOTE]
Yes, of course he does. The sound will not travel beyond his space suit though, as there is no medium capable of carrying sound in space. He will be able to hear himself quite well, though.

Unless maybe you mean if he has his helmet off, in which case all the air in his lungs would be violently expelled before he could even think about screaming.

 

[statickid]

ok then question: if air being violently expelled from your lungs happens to vibrate various membranes and skin flaps so as to make noise that is audible to the only person able to hear this, the person it is happening to, does that count as screaming?

shoot, i think i'm getting off topic.

 

[Izack]

I wouldn't know. I've never died of decompression.

 

[T.Neo]

Actually, whole "killing all the people but leaving the infrastructure intact"thing is a bit of a misconception. Neutron bombs are more of a dirty bomb/conventional nuke hybrid.They typically have a relatively low yield (10-15kt), and throw out massive amounts of radiation, for such a low yield weapon.

Of course, but as the bomb has a low yield it could be detonated in a vacuum close enough to have an effect while still leaving the ship more or less intact.

Transmutation of ship components by the neutrons must also be taken into account.

I wouldn't know. I've never died of decompression.

Aren't there people who experienced decompression and lived?

I think it would be a lot like a "whoosh" sound, with damage to the lungs if the person didn't remember to exhale.

There might also be, uh, gaseous emissions from the digestive system...

 

[Izack]

There might also be, uh, gaseous emissions from the digestive system...

Epic last transmission there. "I think my helmet's cracking." "Can you confirm?" "BRRRRRT!" "Um...?!":rofl:
Okay, it's seriously off-topic now.

 

[SHADO]

the ice armor seems cool.

:rofl:

 

[garyw]

Aren't there people who experienced decompression and lived?

Yes. During the early days of the Soviet space programme cosmonaunts were put into decompression chambers and the pressure was lowered. In at least one case there was a near fatal accident when the pressure was dropped to zero or very near it.

There there was Soyuz-11....

 

[Andy44]

Actually, there was an American in a vacuum chamber whose space suit failed.

http://yarchive.net/space/science/man_in_vacuum.html

"On 14 Dec 1966, a NASA spacesuit technician spent circa 20 seconds in
vacuum when a suit hose failed in a vacuum-chamber test. He lost
consciousness after 12-15 seconds, but regained it when the chamber was
repressurized. Not only did he survive, but he appears to have suffered
no substantial injury, and he had only the most minor symptoms afterward.
See the Roth report ("Rapid (Explosive) Decompression Emergencies in Pressure-
Suited Subjects", Emanuel Roth, NASA CR-1223 (1968)) for details."

 

[Izack]

Hmm...I thought this was about lasers...

Interesting stories about the suit testing though (though 'interesting' isn't a term I would like to apply to Soyuz 11's fate).

Back to armour...
To survive a thermonuclear explosion at medium/close range, what would be the ideal shape? A cone? A solid block? Maybe something not unlike an early space capsule's heat shield?

 

[statickid]

a 4 foot thick lead shield might do the trick. j/k

how about instead of trying to stand it out, having something that makes you deflect from it, not unlike the orion propulsion do-hickey, except done as a survival tactic? it would leave you on some freak trajectory but you could maybe survive!

 

[Andy44]

Something like the pusher plate of Project Orion, which was designed for exactly that purpose.

 

[Izack]

The overwhelming response seems to be an Orion pusher-plate.
According to the wikipedia article, that plate would have been made out of steel or aluminium. Is it really so easy to divert (cough "firepower of that magnitude" cough) an explosion like that? Especially if said explosion is on a less predictable heading, with likely much greater velocity and of course designed to incinerate you instead of push you to Mars?

 

[Andy44]

The charges used by Orion were to be constructed such that they aimed the force of the blast directly at the plate. You don't get any more blast effect than that.

The key to Orion's plate working is that the heat pulse was too short to vaporize the metal (or "ablate" it, which is the correct term). Later designs had a slow oozing of grease onto the plate which would vaporize and provide further protection for the metal.

The reason a nuke is destructive down here is because there is a dense atmosphere to carry the shock wave, which blows buildings down. In space there is no air to carry the wave, so for a nuke to do serious damage it needs to be close enough for the heat and radiation to harm the target. For heat to work against a flying hunk of iron like Orion, you have to be very close, within a few tens or hundreds of meters.

Radiation, on the other hand, depends on how well the ship's electronics and crew are shielded. Even with lots of lead, the neutron flux may serious harm the crew. The "ice shield" idea may be good, since water is a good neutron shield.