05-06-2003 01:27									#91
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quote: Originally posted by Cruddy A stealth vehicle invisible to IR sensors IN SPACE???? That means the whole ship has to be about absolute zero - very chilly for the crew! I honestly don't see how you could have stealth in IR frequencies. Radio yes, light yes, but heat? That's the product of just about every physical process. Anyone got any bright ideas on this?

A ship in orbit would probably be able to use the heat signature of the planet to hide its own signature.

Also, the sun has a huge heat signature in space. Ships could try to attack "with the sun behind them" so that from the enemy's perspective, their heat signature would get lost in the sun's.

If you could shift the IR wavelength to a different wavelength, you could essentially convert the IR into a different form of EM radiation. Your IR signature would be reduced, but your signature in a different wavelength would be increased. Of course, the enemy would not necessarily know what wavelength to search, so it would have to search all wavelengths, to find where your signature is maximum.

	05-06-2003 01:50									#92
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Elite... 2nd best game in my list. (First is Star Control 2).

	05-06-2003 07:14									#93
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Why not convert heat to some other form of power, like electricity?

	05-06-2003 09:04									#94
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quote: Originally posted by Cruddy A stealth vehicle invisible to IR sensors IN SPACE???? That means the whole ship has to be about absolute zero - very chilly for the crew!

It's more like 4.3K, exactly the same temperature as the background radiation.

It means the ship has to have perfect insulation, that it doesn't travel fast enough to generate heat, and that it isn't anywhere close to a star to radiate off absorbed heat.

	05-06-2003 09:10									#95
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quote: Originally posted by chegitz guevara Why not convert heat to some other form of power, like electricity?

All known conversion processes involve losses. They are not 100% efficient, which still leaves a heat trail.

If we could do it effectively, we'd have virtually free energy. Just put the geerators in the Sahara/Mojave wherever deserts and watch the watts pump out.

Urban, are you agreeing or disagreeing? It's kind of hard to tell - I think you are saying it's technically possible with the right sort of technology.

ANYTHING'S POSSIBLE with the right sort of technology.

	05-06-2003 09:10									#96
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quote: Originally posted by chegitz guevara Why not convert heat to some other form of power, like electricity?

There are all sorts of reasons. For example, the ship may be giving off IR radiation due to proximity to a star. To convert that into another form of energy, you need to "suck" it from the hull, which is probably more costly than staying away from said star to begin with.

	05-06-2003 09:12									#97
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quote: Originally posted by Cruddy Urban, are you agreeing or disagreeing? It's kind of hard to tell - I think you are saying it's technically possible with the right sort of technology.

All I was saying was the ship doesn't have to be 0K inside In fact, a ship at 0K on the outer hull will show up darker than the background on IR

	05-06-2003 09:26									#98
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I remember a short story in Dragon magazine, back in the eighties, that involved a space battle. The ship in question was a heavily armored sphere (10s of meters of iron and concrete, with internal water buffers, IIRC), and a relatively small crew. Armament consisted of kiloton-range nukes using fusion rockets, which were 'launched' by inertia -- the ship was slowly spinning, and it just a matter of opening the lauch door and relasing a clamp. After drifting out a klick or two, the missle would fire up its engine and be on its way. The only other weapons were chemical-propeled nukes used to knock out incoming missles at moderate ranges, heavy chainguns used phalenx-style to intercept at pitifully short ranges. The nukes didn't actully have to hit to kill or cripple a ship -- within a few klicks would be good enough.


Ranges were at around 50,000 km or so, the ships used passive detection (very submerine-like), and exchanges (the story only had the one) took forty minutes for the fusion rockets to cross paths.

It struck me as being the most likely scenario for interplanetary space combat I have ever read.

	05-06-2003 10:08									#99
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That's not pleasant reading. The winners get to die more slowly than the losers. Some victory.

I agree though, with the exception of the fusion powered rocket's it's all doable - with the problem that you kinetic energy Phalanx cannons are going to throw the spin and the careful aiming system out the window.

Oh yeah, how does a chemically powered rocket intercept an incoming fusion powered nuke? I don't get that bit.

And why not use lasers or PAs on the close in defense? Maybe bulk and power would be a factor here - although a sphere with a hull 10s of metres thick would have a fair bit of internal volume. Any idea what diameter we are talking here?

I used to collect Dragon but I stopped ages ago. It was not economically viable from my UK POV.

	05-06-2003 10:28									#100
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quote: Originally posted by The Mad Monk Ranges were at around 50,000 km or so, the ships used passive detection (very submerine-like), and exchanges (the story only had the one) took forty minutes for the fusion rockets to cross paths.

The question is, how do they target? Torpedoes can be wire guided, but that is absolutely out of the question here. If only passive guidance is used, it's not likely that they would come close to anything in space.

Also, nukes are a lot less effective in space, as there's no medium to transmit the shockwaves.

	05-06-2003 10:28									#101
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As I recall, the ship itself was in the neighborhood of 120-150 meters in diamter, with maybe a 20 meter sphere dead-center that housed the crew -- ridiculously overarmored for anything less than a nuke exchange, and slow as hell.

The counternukes were chemical becuase that was cheaper, lighter, and only had to go thirty or so klicks in ten minutes to make the intercepts.

As for energy weapons -- the ship depended on stealth and armor, in that order, there wouldn't be room for the power plant required. As it was, it took them weeks to go anywhere.

I think they were stationed near the asteroid belt, as a picket.

	05-06-2003 10:42									#102
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quote: Originally posted by Urban Ranger The question is, how do they target? Torpedoes can be wire guided, but that is absolutely out of the question here. If only passive guidance is used, it's not likely that they would come close to anything in space. Also, nukes are a lot less effective in space, as there's no medium to transmit the shockwaves.

I believe the warheads in this case were designed for soft x-ray kill effects.

	05-06-2003 10:55									#103
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quote: Originally posted by The Mad Monk I believe the warheads in this case were designed for soft x-ray kill effects.

Then they can be stopped by a thin sheet of lead lining.

	05-06-2003 10:56									#104
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I'll take your word on it.

	05-06-2003 11:13									#106
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Just wondering -- if there is no shockwave, what does transmit the energy generated?

	05-06-2003 11:16									#107
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Come to think of it...how do young stars manage to push all debris from themselves?

	05-06-2003 13:27									#108
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quote: Originally posted by Colon But you don't need fuel to keep an object moving, only to make it accelerate. (whatever the means of propulsion is) And since it will keep moving, it is bound to hit something at some time.

What I mean is that a missle is going to have to have some sort of fuse, which is going to require some sort of power unit (assuming nuclear) to tell it to explode. Otherwise it's just going to go splat, like so many nuclear bombs have done in airplane crashes.

Kinetic weapons of course are just going to hit stuff, but I doubt that many of them will be all that large, certainly not as large as the asteroids that smack into the atmosphere regularly. With no atmosphere of course, a lucky hit could be bad, but the odds are infinitesimal IMO.

	05-06-2003 13:31									#109
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quote: Originally posted by Cruddy Hi folks. Fascinating thread. For those who fancy trying some of these ideas, there's a family of games (old timers will know about it) called Elite and Frontier. The last version is called First Encounters and is available as shareware from the author (who won the copyright back in court. Ming, don't go cussing me). Download PC versions here You will also need JJFFE (or similar) to run Frontier First Encounters on Windows or Linux systems. Get your JJFFEWIN OR Linux here They are very compact games and run on the desktop. Elite 4 is under construction, supposedly with multiplay. Happy shooting. EDIT: Elite was heavily influenced by an OLDDDD RPG called Traveller - it's pre D&D, that's how old. Megatrav came out (late 80s?) with an updated ship design system that was even sillier. Honestly, a naval architect friend of mine couldn't believe the amount of errors in the rules.

I remember D&D coming out in 1973, and Traveller coming out in about 1975. Was there an earlier version that I missed, perhaps pre-GDW?

Anyway, Traveller was a great game for its time. I'm kind of suprised that it hasn't caught on more in the online RP world. I see (and play) a lot of Engarde! (another GDW RP game from about 1975) out there, but Traveller seems to have disappeared.

	05-06-2003 13:33									#110
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quote: Originally posted by Cruddy This is quite true, but the problem with kinetic weapons is that they are inherently "dumb". They won't make a course change if the target takes evasive action. It's also difficult to calculate the correct trajectory if the relative speed of firer and target is in the several KMs per second range. It may seem impossible to detect such a small object at a meaningful distance, but even current battlefield artillery radar can detect small birds or even butterflies at a distance of several hundred metres. Not terribly useful when you're on the lookout for incoming mortar and LCG shells, but I hope you take my point.

This is why I mentioned the need for terminal guidance or short ranges for kinetic projectiles. They will need an active propulsion system to maneuver, as fins (as used by smartillery shells) will be of no use.

	05-06-2003 13:38									#111
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quote: Originally posted by Sandman Regarding stealth spacecraft: Whilst they may have a role to play, it will probably be limited for the following reasons : Stealth coating is very expensive. The cost of the ship would rise by a huge amount, particularly if it had a high surface area design, like a needle or a disc. Stealth coating requires a lot of maintainence to remain efficient, meaning that stealth ships will need a larger logistics train to operate effectively. On long missions, the stealth coating could become eroded by micro-meteorites, rendering it useless. A stealthed ship will absord most incoming radiation in order to remain undetected. This will create problems with dispensing with heat. One solution would be internal refridgeration systems that can absorb a limited amount of heat, until they have to be expunged, this would be the equivalent of rigging for silent running. Another solution would be external radiators that can be deployed on the surface of the ship to dump excess heat on a continuous basis. For stealth ships, these could be directed away from probable areas of enemy observation. Finally, a stealth ship would be very vulnerable to lasers.

This is why you would want to only stealth the pointy end of a needleship. This reduces cross-section and allows all of these weaknesses to be dealt with as cheaply as possible. The trick is going to be keeping it pointing in the right direction, something that won't be all that difficult for an attack on an enemy base, planet etc., or for reacting to data forwarded by remote sensors.

	05-06-2003 13:41									#112
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quote: Originally posted by Cruddy A stealth vehicle invisible to IR sensors IN SPACE???? That means the whole ship has to be about absolute zero - very chilly for the crew! I honestly don't see how you could have stealth in IR frequencies. Radio yes, light yes, but heat? That's the product of just about every physical process. Anyone got any bright ideas on this?

If you have enough energy you can re-arrange the heat in your ship so that it stays inside while the cold is pushed to the outside of the ship. This would make you harder to discern at longer ranges, but there is no simple way of cheating the system. Chemical means might be able to cool the ship in the short run, but they will be expended.

	05-06-2003 13:47									#113
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there are no shock waves as on earth after a nuclear blast in space, but i can imagine that if suddenly several kilotons of energy hit your ship, the effects will be quite devastating ...

	05-06-2003 13:51									#114
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quote: Originally posted by Sikander I remember D&D coming out in 1973, and Traveller coming out in about 1975. Was there an earlier version that I missed, perhaps pre-GDW? Anyway, Traveller was a great game for its time. I'm kind of suprised that it hasn't caught on more in the online RP world. I see (and play) a lot of Engarde! (another GDW RP game from about 1975) out there, but Traveller seems to have disappeared.

I still have the small, black box, with all the booklets.

I also have Megatraveller; I had a lot of fun designing ships under that system, after I made some suitable adjustments.

	05-06-2003 14:01									#115
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quote: Originally posted by Sikander I remember D&D coming out in 1973, and Traveller coming out in about 1975. Was there an earlier version that I missed, perhaps pre-GDW? Anyway, Traveller was a great game for its time. I'm kind of suprised that it hasn't caught on more in the online RP world....

IIRC, Traveller was born out of Marc Miller's Vietnam service. So although it was published later than D&D, the game was being play tested years before "fantasy rules for table top gaming" (D&D) entered Gary Gygax's head.

Traveller is very hard to referee well. It's much more open ended and flexible than fantasy RPGs, which could explain why it has had zero impact on the online scene. Sensible developers tend to go for the art of the possible, rather than the most imaginative games The solo play Megatrav games of the 90s were - well, average at best.

Wouldn't GDW would sue anybody's arse off if they tried it?

	05-06-2003 14:04									#116
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quote: Originally posted by dannubis there are no shock waves as on earth after a nuclear blast in space, but i can imagine that if suddenly several kilotons of energy hit your ship, the effects will be quite devastating ...

There is no atmosphere to propagate the blast wave - but there is also no atmosphere to soak up the radiation. You get full load, minus inverse squared law.

	05-06-2003 14:11									#117
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Also, there's this little thing called "radiation pressure".

About GDW: I don't think they matter anymore.

Steve Jackson owns Traveller now.

	05-06-2003 14:20									#118
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Does he really? About time I heard something new on Apolyton. I'm glad GDW bit the dust, they were complete ****heads to a very good friend of mine.

Still - lot of design work to get an official computer game license.

	05-06-2003 14:37									#119
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quote: Originally posted by The Mad Monk Just wondering -- if there is no shockwave, what does transmit the energy generated?

You get all sorts of radiations - fast neutrons, photons, EM waves, x-rays, etc., etc.

As for young stars, they are just throwing out matter and energy. The energy must be in radiation form, though, since there's no medium to transmit it.

	05-06-2003 14:40									#120
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quote: Originally posted by Cruddy Traveller is very hard to referee well. It's much more open ended and flexible than fantasy RPGs, which could explain why it has had zero impact on the online scene. Sensible developers tend to go for the art of the possible, rather than the most imaginative games The solo play Megatrav games of the 90s were - well, average at best.

The big complaint against Traveller is that the game is sterile. Once your character musters out, he or she is fixed. There's no growth whatsoever. It's the first sci-fi RPG, and unfortunately, the worst one.