Transterrestrial Musings

Comments

Rand,

His article was pretty interesting. One of the things that first got me interested in engineering and space development was my intrest in SciFi RPGs back when I was a teenager. One of them had a fairly realistic space naval combat system (excepting a reaction drive that had ridiculously high specific impule compared to the amount of power being input), so the topic of real space naval warfare has always been interesting to me. This may sound idiosynchratic, being anti-war and all, but the reality is that I'm not passivist. I believe that defensive wars are justified and often there is no choice but to fight them (I just don't feel that even 10% of the wars we've fought in as a nation fall under that category).

That said, I had a few technical thoughts about what he said. In no particular order:

I think he was slightly pessimistic on the possibility of stealth. While addimittedly, these vessels would be consuming enormous amounts of power, and they do have to be radiated away, would it not be possible to control the directions where the main radiation went? Ie having coolers inside the skins on forward facing sections, and having all the radiators facing in directions to the rear or sides? If you do the angles right, and keep those radiators facing in a direction away from where you were heading, couldn't that provide a decent amount of IR masking? Sure if you had enemies in all directions, it wouldn't do any good, but if you had a good idea what main directions you could expect your enemies to be located, couldn't you use such a system?

IR would still be important, but not as powerful as he describes it.

Also, with regards to the parallax bit. If you were coming in from a very hot source that covered a sufficiently large portion of the sky (say you were flying with between them and the sun), might it be possible to avoid detection until you were actually close enough that one of the sensors near the edges could catch you against a cooler background? I'm not positive on that one.

Regarding radiators. It may be possible to have as he says temporary heat handling systems that would allow the overall amount of radiators to be decreased (or to allow them to be temporarily covered during combat). Ie heat sinks of some sort. You'd have to release the heat at some point, but if you can have your radiators sized for a smaller heat flux than the peak level, and use the heat sinks as load levelers, there seems to be some potential advantages.......stuff like Lithium Hydride would be nice.

Energy Weapons would likely want to operate in a pulsed configuration. Rapid pulses are much more effective at cutting, and might not generate as much heat. It requires systems that can take that massive influx of electricity (and spike in heat) as well as the ultra-fine pointing needed, but would seem to allow lasers and particle accelerators to be more useful.

Lastly regarding Particle Accelerators, I think they would fire a neutral beam, fairly similar to how some ion drives work. Basically, you ionize the particles, accelerate them, then just before dumping them out of the vehicle, you pump the electrons back in. I know it is more complicated than all that, but neutral beams might be a bit easier to deal with than two oppositely charged beams......

Anyhow, I don't know if you really want to get a discussion about this started up on your site or not. I just figured it would be good to comment on his stuff somewhere.

~Jon

Posted by Jonathan Goff at April 20, 2004 10:58 AM

Until you nail down the concept of "shields" and "artificial gravity", any discussion of weaponry or propulsion is academic.

Puttering along at .50 of lightspeed is nice...right up to the point you hit that micro-particle of interstellar dust. As Marvin used to say: "Earth-shattering Kaboom!"

Posted by Bob at April 20, 2004 01:17 PM

Yet in this current time-space continuum, the Pentagon has assigned space to the Air Force, and they've made notably little progress with it.

Didn't the politicians ground the AF (Dyna-Soar) in favor of political showboating (Apollo)?

Posted by D Anghelone at April 20, 2004 02:00 PM

No, there was no relationship between Apollo and Dynasoar--one was civilian and the other military. They each had their own purpose, but the Air Force decided that it had no use for man in space at that time, when it cancelled both Dynasoar and Manned Orbiting Laboratory, and is only now starting to decide that it might have one.

Posted by Rand Simberg at April 20, 2004 02:13 PM

He can be interesting to read, but he’s very quick to say what CAN’T happen, and forgets that sneaky little details can make a big difference. I agree up to a point – Star Trek type “magic technology” shows are fun, but there is plenty of room in known physics for space battle, and it is worth discussing.

There is also the real, near term, but different, issue that the U.S. now depends on space assets (GPS and spysats anyone?) to prosecute war. We need to defend those assets but haven’t even started.

Some of the things I think he is forgetting to various degrees: Space is big. Relative velocities can be VERY high. Space isn’t quite empty. Orbital mechanics allows for all sorts of interesting tricks. Planets, moons, etc. make handy hiding places. Spacecraft will be built very differently from anything on earth. Barring advanced or powerful (Orion) nuclear propulsion, they will be built light, like aircraft – no foot thick steel plating!

As Jonathan said, you can direct your radiators. You can also have large, very thin shields made of carbon or other materials to hide ships behind. You can hide around a planet and fire a missile over the horizon. A fast, cold, stealthed missile flying at +18,000 mph relative velocity could be very hard to detect in time to intercept, especially if it lets go of a payload of tungsten BBs soon before striking.

In Skylab and ISS, engineers made a number of “user interface” errors (like things you are likely to bang into, hard, when moving about) because they simply had no intuitive grasp of the environment. When we do start building space warships, I have no doubt there will be many surprises.

Posted by VR at April 20, 2004 04:01 PM

Pretty good read, but space war will offer far more options than he's touched upon. For instance, just what will even wideband impulse radar (which he mentions with his 'glissando' reference) make of a ship using an M2P2 as a shield? Attack over distances with appreciable light time delays (say 100 000 km) will be tough by any means, whether the weapons are lasers, particle beams, railguns, cannon, or a rock & sling (OK, tethered system, but you get the idea). However, maneuver will be critical -- just as with fighter jets, you'll want to remain in a position where you have greater available energy than your opponent. And don't forget, without invoking vacuum energy powered impulse drives, you're going to be using good old high thrust rocketry (even if nuclear powered), so your ability to maneuver is limited by your propellant mass fraction...

Having said that, here's my counter to his IR... If I fire clumps of carbon fiber from a railgun at say 20 km/s, the stuff should fairly quickly reach the local blackbody temp (for whatever distance from the sun you're fighting at). So, if I happen to saturate the opponent's IR focal plane arrays with lasers around the blackbody peak wavelength, they'll likely stand only a small chance of seeing that I've fired the junk. Maneuver if you want when you detect me dazzling you, I'll just blow more of the crap out of the gun to intercept your new course. Rinse & repeat until your tanks are dry. (At which point I may decide to not even destroy you, just cut off your refuelers and you can surrender or keep drifting.)

BTW, a high power microwave weapon might be a good defense against the crud (literally blow it aside), but there's no guarantee my gun & my lasers are on the same bearing.

- Eric.

Posted by Eric Strobel at April 20, 2004 05:56 PM

I truly mean no offense but I recall differently as do others:

In the end, the Air Force was pressured by the Nixon Administration to accept participation in the space shuttle program in lieu of separate development of their own designs.

Dyna-Soar was seemingly doomed from birth over controversy over its mission and the lack of a strong sponsor. The Eisenhower administration wanted to limit it to suborbital missions (so as not to infringe on the new NASA agency's mission of manned orbital flight). Once Eisenhower was replaced by Kennedy, the catastrophic new Secretary of Defence, Robert McNamara, began to work his malignant magic. There was no weapons system immediately resulting from Dyna-Soar. Nor did he believe there was any need for the military to waste so much money on an aeronautical research vehicle. The back-and-forth was extremely tedious and can be traced through the chronology below. Suffice to say after reviews, audits, and special studies ad nauseum the project was killed by McNamara in December 1963.

Encyclopedia Astronautica

Boeing makes a dramatic statement for a FedGov contractor:

Dyna Soar actually reached the full-scale engineering mockup stage before it was canceled in December 1963 - a major blunder for American techno-logical leadership in space.

X-20

Posted by D Anghelone at April 20, 2004 07:32 PM

DenBeste writes an interesting piece but I think he overestimates manueverability in space (especially regarding missiles)...

I think a likely weapon, in a first strike capacity would be to get a reasonably sized asteroid (at least bigger than your warship but not too big that you couldn't get it up to speed) up to speed and come in behind it. The asteroid would mask your own heat and have a better IR signature. Certainly they'd spot it and know the jig was up but an enemy fleet would then have to scatter to avoid the asteroid.

The advantage is that a few non-combatant space tugs could be used to get the asteroids up to speed and then stays behind, letting the faster warships finish up. Now imagine if you had a few of these asteroids.

The other thing would be to have your ship powerdown and drift. You might have a small IR signature until you power up your machine guns. A bullet at high speed would do a lot of damage. You could even get one to follow a curved course if you fired from behind the cover of a planet. Suddenly its raining bullets on your enemy if you calculated correctly. Ouch.

Posted by ruprecht at April 20, 2004 09:01 PM

No offense taken, but this does nothing to support your position with respect to Apollo and Dynasoar. Apollo was not Shuttle.

Posted by Rand Simberg at April 20, 2004 09:09 PM

as far as AF vs. Navy, look at the difference in duties and responsibilities between the pilot of an aircraft and the CO of a ship. The AF Pilot is given an operational plan to carry out. All the heavy lifting, maintenance, and support staff are back at the base, the airplane is only the striking arm of the Air Force. The AF pilot is not the supervisor for his flight crew (if he has one) or for the ground crew (that *really* owns the bird the pilot is allowed to fly)....

In the Navy a warship is expected to be fairly independent, up to and including battle damage repairs, so they carry a LOT more people than are needed to run the ship, plus a lot of tools and spares for mainenance. I was stationed on a Fast Attack sub and about the only maintenance we *didn't* do was on the Roots blower for the ship's Diesel engine. The CO of a ship is the ultimate supervisor for the entire crew and is answerable for their actions to the upper echelons. If a Navy ship runs aground the CO is at fault (no matter who was Officer of the Deck).

Heck, in the Days of Sail as soon as their home port went under the horizon the Captain of the ship was an absolute sovereign over his command, with the power of life and death over his crew.

Similarly, the AF pilot is *relatively* young, while the Navy CO is a senior officer.

Our current space effort is the AF model.

Future Space fleets will be more in the Naval model.

Posted by Rick Tengdin at April 20, 2004 09:53 PM

One question I had that the Denbeste article didn't address; are nukes actually very effective weapons in space?

Nuclear fission/fusion reactions mostly give off radiation; in the atmosphere, much of that is absorbed by nearby air and converted to heat and thus to a pressure wave. In space, though, a nuke would just give off a uniform expanding sphere of radiation (plus, I suppose, a very-high-energy and very thin shell of particles); at what distance is that actually dangerous?

Posted by mike earl at April 21, 2004 07:11 AM

Navy vs Air Force. I think Rick Tengdin hit the nail on the head more-or-less. The main difference is the ability to act independantly on a long term mission. I think the Air Force has much more specific rules of engagement and are much more limited in action because of the nature of their missions.

So I guess a lot of what we're talking about depends on if our space fleet is running around our own solar system (communications with command back home is still possible, if delayed) or capable of going to another solar system (communications are helplessly beyond our capacity).

Still, once things start going in one direction it will be difficult to change them even if the alternative makes more sense.

Posted by ruprecht at April 21, 2004 07:49 AM

I think that Den Beste may have been off-base by discounting nuclear warheads for space-to-space use.
1- while there probably still would be a ban on using them planetside most of the reasons (both practical and emotional) to do so would not apply to a spaceside fleet-on-fleet action.
2- if particle beam weapons really do have the effects Den Beste hypothesizes, you're going to be applying most of the effects of a nuclear weapon to your target anyway
3- Nukes are just lots more efficient at wrecking stuff than chemical warheads.

Practically this will mean that missile defense will be a LOT more important.

Posted by Dave P. at April 21, 2004 11:26 AM

Drawing on the Navy vs. Air Force comments, it begins to appear that a multi-branch service would exist in space as on the ground.

A Navy-like deep space service would be for outsystem operations, carrying Marines equivalents for the messy work. If there's a need to invade, capture and occupy an inhabited planet, something like an Army would be brought in.

An Aerospace Force would serve as the insystem defensive arm, in conjunction with an Army command detailed with closer-to-home missions.

Posted by McGehee at April 21, 2004 01:26 PM

On nukes in space: A nuke produces a lot of gamma and x-ray, with quite a lot of energy all across the EM spectrum. If there is a lot of mass around it (air/water/rock) most of that gets turned into heat. Most of the blast is due to all the surrounding mass, not the bomb itself. In space, you get huge EMP and surface heating effects, but not all that much in blast effects. The EMP might even be the biggest concern except for very close-in fights.

I noticed Denbeste doesn’t even want e-mail on the subject. I guess after some of his mistakes in discussing earlier space subjects he doesn’t want to hear criticism on this one.

My feeling is that by the time comes, things will change so much that at this point it is just fun speculation. For example, autonomous weapons systems are bound to get much better, and you can have undetectable communication in space with a well-focused laser (unless somebody gets in the way of the beam and is looking). So I might expect to see a lot of networked small semi-autonomous spy and weapon craft with human run ships avoiding direct combat as much as possible. And I think he is very wrong on stealth – stealth is never perfect, and I wouldn’t expect it to be. But I do think it would play a big part.

Posted by VR at April 21, 2004 04:54 PM

On nukes in space warfare...

In general, no atmosphere, no EMP. And given a few hundred kg of bomb, not a whole lot of fireball, but enough radiant intensity to ablate your hull pretty good. So I'll just leave you w/ one final word on nukes in this context:

ORION.

- Eric.

Posted by Eric Strobel at April 21, 2004 07:25 PM

On stealth in space warfare...

Of course Den Beste is right about stealth, just look at all the alien probes we see orbiting throughout our solar system... Oh, wait... Nevermind... ;-)

- Eric.

Posted by Eric Strobel at April 21, 2004 07:30 PM

Re autonomous weapons. I think Keith Laumer's Bolo and Fred Saberhagen's Berserker series show the problems with this class of weapon (unless it has multiple shutdowns to make the thing inert when the battle is over.

The last thing you need is a bunch of missle-bearing drones flying around engaging your civilian traffic........

Lots of laser-linked spybots is much more likely IMO, and you could use a launching laser to boost a small drone to a very high speed, then cut it loose for a flyby (or sniper shot) at an opponent.

Posted by Rick Tengdin at April 21, 2004 08:03 PM

On 'defenses'...
Don't think "Star Trek" instead think "Galaxy Quest" :o)

Plasma 'armor' or 'shields' is what the military is concentrating on currently.

I can't find it at the moment, (I'm at work :o) but there was an article about a year ago, (AW&ST I think) on research into plasma 'shieilds' that were capable of being tuned to absorb certian types of radiation.

(The article mainly focused on the idea of using these plasma shields for 'stealth' for satillites, but I noted they didn't mention the PROBLEM of increased IR signiture :o)

By varying the composition and temperature of the plasma different types of EM radiation could be absorbed. This, of course, would also help with a ships heat problems beings you can 'dump' heat into the plasma production gear.
(I'd note that one concept already under study by NASA and others surrounds the space craft with a magnetic field containing a 'plasma atmosphere' to surf the solar wind...hmmmm :o)

As for space weapons, it's been a long while since my 'Directed Energy Weapons' stuff, but I seem to recall that Neutral particle beams are used in space and Charged particle beams inside the magneto-sphere. It might be the other way around though :o)

Interestingly enough, a lot of good info can be found in various forums of Sci-Fi writing, and RPGs and articles there-in.
I recall Traveller had a great many VERY technically acurate pieces on lasers, while the Baen website forums had some good info on space missiles, beamed energy, and nuclear explosion physics.

Randy

Posted by Randy Campbell at April 22, 2004 07:47 AM

Re: 'Smart' weapons- most of the 'Frankenstein' problems can be solved in the design stage. As Robert Taylor points out, there are some prety good reasons NOT to make your intelligent, autonomous weapons either TOO intelligent or TOO autonomous.
And if this lot ISN'T reading Sclock Mercenary (www.Schlockmercenary.com) they should be.

Posted by Dave P. at April 22, 2004 07:48 AM

Yup, looks like I made a mistake on EMP. Though it is more like "little EMP" than none. The nastiness in early high-altitude tests apparently had more to do with particle interaction with earth's mag field than EMP.

In regards to Orion, it usually is assumed to use relatively small bombs. A megaton+ bomb would be worse, but again, other effects would drown EMP in space - unless it was designed to enhance that.

On weapons - I wouldn't like or expect completely autonomous weapons, but would expect systems in the next several decades could do far more without phoning home than currently. In any event, a network would be far more powerful than individual devices working alone.

Posted by VR at April 22, 2004 01:01 PM

VR,

I seem to recall that the early high-altitude shots (Starfish, or something like that) caused genuine EMP. EMP is caused by the x-ray pulse getting absorbed at a particular density level in the atmosphere. IIRC the physics discussion, the sudden ionization causes a charge separation -- the electrons that absorb the x-rays fly off -- but they can't go too far in the atmosphere. They recombine abruptly, so you've got a very abrupt current flow that causes an equally abrupt EM pulse. That's the 'Readers Digest' version anyway.

- Eric.

Posted by Eric Strobel at April 22, 2004 05:18 PM

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