TBX in space

[Corvus 501]

What would happen if you used (modified) thermobaric explosives in space? Instead of the standard explosives used in fuel air bombs, the warhead would use an oxidized explosive. The main advantage to this type of warhead is that if you set off sevral of them around a ship (or one massive one) and detonate them together, you should crush the ship like a tin can.

[Lord Revan]

What would happen if you used (modified) thermobaric explosives in space? Instead of the standard explosives used in fuel air bombs, the warhead would use an oxidized explosive. The main advantage to this type of warhead is that if you set off sevral of them around a ship (or one massive one) and detonate them together, you should crush the ship like a tin can.

Why would they crush the ship?

Space is empty, there won't be any real shockwave. IIRC apart from nukes and fragmentations warheads, modern explosives are more or less useless in outerspace. Nukes work as a nuclear "detonation" will create a massive radiation spike and frag warheads will essentially create a cloud of micro meteroids, but anything that relies on shockwaves to deal the most of their damage are useless in space as there's no material to create a shockwave from.

[Batman]

Thermobarics don't work outside the atmosphere and are moderately useless against anything reasonably well armoured as long as it's airtight (you know, like a spaceship kinda has to be) even inside.

[Corvus 501]

Basicly, you are hitting the ship with a huge volume of fast moveing gas. Instead of the standard concussive effect of a conventional explosive detonating in contact with the hull, the explosive dust released by them missiles detonate all around the ship, damaging any weak points.

[Jub]

Basicly, you are hitting the ship with a huge volume of fast moveing gas. Instead of the standard concussive effect of a conventional explosive detonating in contact with the hull, the explosive dust released by them missiles detonate all around the ship, damaging any weak points.

Except that small mass fast moving particles are going to be an issue anything that spends time out of a safe orbit will need a solution to. Plus even with a focused explosion there just isn't going to be that much mass to send the ship's way. Why not just use a nuke, a fragmentation warhead, an explosively launched penetrating dart, a literal gun that just uses the rocket engine to get in range, or a bomb pumped laser to do the same job better?

[Batman]

Hog and wash. Unless your bomb weights in at several thousand tons (and I think that's may be conservative) there's not going to be a huge volume of gas because the bomb would have to provide all the gas. But hey, if you want to build bombs that actually weigh in at several KT just to mimic the effects of FAEs on earth (which means little if any against armoured targets) be my guest.

[Lord Revan]

well the thing is that it doesn't take much of a distance for the inverse cube law to turn that cloud of gas into something that's mostly harmless. and besides any spacecraft capable of atmospharic re-entry must be capable of dealing with superheated fast moving gas.

Solar-wind is in essense just truly massive amount of superheated gas constantly hitting earth but due the distance it's so disperse that it's mostly harmless.

the formula for the area of sphare is A=4(pi)r2 where r=radius in meters, the fomula of volume of a sphare is (4/3)(pi)r3, so at mere 1 m from the epicentre the area is 12 m2 and it will only get bigger when the r variable becomes a factor (12=1), and please do remember that in space combat terms 1 m is practically touching the opponent

and as Batman pointed out you can't have more matter contained in the explotion then bomb orginally had.

[Batman]

It's the inverse square law actually and technically a) not every spacecraft does need to be reentry capable and b) those that do don't necessarily have to deal with superheated fast-moving gas. Plenty of SciFi civilisations have the technology to make atmospheric entry/exit as slowly as they choose.
That being said you're completely correct of course, every civilization that doesn't want for its spaceships to take freaking forever to reach leave alone break orbit will have to deal with that

[Lord Revan]

It's the inverse square law actually and technically a) not every spacecraft does need to be reentry capable and b) those that do don't necessarily have to deal with superheated fast-moving gas. Plenty of SciFi civilisations have the technology to make atmospheric entry/exit as slowly as they choose.
That being said you're completely correct of course, every civilization that doesn't want for its spaceships to take freaking forever to reach leave alone break orbit will have to deal with that

I was trying to remember the term, I don't have to use that so often and I'm not an native english speaker anyway so mistakes happen.

[Simon_Jester]

The density of the gas cloud varies inversely with the cube of its radius. The number of particles in an exploding debris/gas cloud that hit a target of fixed area varies inversely with the square. Either might be appropraite depending on the context.

But yeah, this thing really isn't going to be a worthwhile weapon. There's a reason that thermobaric weapons aren't even universally adopted as weapons on Earth; they're flashy and effective under certain favorable conditions, but that doesn't translate into a weapon that reliably solves all problems. And in space where atmospheric dynamics aren't helping make the bomb work, there is very little advantage to the things.

[Corvus 501]

I'm not talking about attacking shuttles with one missle, I'm talking about attacking cruisers with missle swarms of hundreds.

[Lord Revan]

either way what's important here is the r term as it's the only variable, if we take a series of values of r between 1 and 6, r2 varies between 1 and 36 and r3 between 1 and 216
needless to say it this isn't gonna work as I, Batman and Simon have pointed out the bomb simply won't have the mass to be effective.

Thermobaric weapons work via shockwaves it's in the bloody name and a bomb won't have enough mass to create a meaningful shockwave in hard vacuum. outside of atmossphere these weapons would an effective range of meters or tens of meters at most.

basically you'd sending hundreds of your special missiles to do job that a single nuke could easily do and with a greater effective range too as the gamma brust rely on mass of the projectile to do any damage.

and for the love of everything that's holy please do remember that r is in meters, also remember how insignifigantly small distance a meter is when talking about space combat.

basically you idea is not some undiscorved superweapon but rather it takes job that a lot things do better and uses way more resources to do it.

lets say you were a byrocrat that had to deside which of 2 proposed weapons systems to fund and you had one where you had to use massive swarms of missile to do any signifigant harm and even then the effect range of the wraheads was pityful and another where you had to use 1 missile to do the same task as the other systems and the effective range of the warhead was better too. I think about it that way.

[Batman]

Ah, but what if said swarm of essentially useless missiles are manufactured in that bureaucrats home state while the nuke is built elsewhere?

[Zaune]

You'd be better off using whatever clever chemical process you've devised to make something combust in hard vaccuum to do direct-contact thermal damage with something slow-burning. Or in other words, napalm in space.

[Eternal_Freedom]

If you could somehow make it burn in space, wouldn't thermite be more effective?

[Zeropoint]

Ah, but what if said swarm of essentially useless missiles are manufactured in that bureaucrats home state while the nuke is built elsewhere?

See that some money ends up in my campaign fund and we'll talk.

[Jub]

If you could somehow make it burn in space, wouldn't thermite be more effective?

Thermite already will burn in space as it carries its own oxidizer in the form of rust. The biggest issue is that you need a direct hit to make this kind of weapon effective where as a nuke or shrapnel device will have far greater AOE potential. Still, it might be a good way to finish off a ship blinded and crippled by a nuke and thus unable to dodge or defend itself.

[Eternal_Freedom]

Don't you need a high temperature ignition source to kick off the thermite reaction? We always used a magnesium strip in chemistry practicals, and that would need Oxygen to burn, at least initially.

I could see the thermite being used as a more precise weapon, say you want to disable engines or a particular weapon mount, you can literally burn it off the hull, rather than the far less precise "bung a nuke at it" method.

[Simon_Jester]

I'm not talking about attacking shuttles with one missle, I'm talking about attacking cruisers with missle swarms of hundreds.

Even worse. This 'cruiser' will presumably have a solid layer of some kind of armor plating covering its entire hull.

Think. Spacecraft have to hold an atmosphere inside themselves- that's fourteen pounds of force per square inch of hull, pressing outward. How do you propose to seriously threaten that by applying LESS pressure from the outside of the hull? That won't even cancel out the interior pressure actively trying to tear the hull apart from inside, let alone exert meaningful crushing force.

A thin, pressurized shell (like a modern space shuttle) could conceivably be destabilized and crushed by external pressure... but your 'thermobaric' weapons are very poorly suited to supplying that pressure.

And against a well armored hull that is presumably designed to survive impacts from high-velocity kinetic rounds or high-energy beam weapons? Not even worth thinking about what would happen.

If you could somehow make it burn in space, wouldn't thermite be more effective?

Thermite already will burn in space as it carries its own oxidizer in the form of rust. The biggest issue is that you need a direct hit to make this kind of weapon effective where as a nuke or shrapnel device will have far greater AOE potential. Still, it might be a good way to finish off a ship blinded and crippled by a nuke and thus unable to dodge or defend itself.

A second nuclear warhead to follow up after the first would be even better- because anything that can be wrecked by a few tons of thermite will be a lot more wrecked by a nuclear device initiating in contact with the hull.

Basically, the heart of the problem here is that chemical reactions just don't pack very much punch compared to the speeds and energies required in space. This is why chemical rocketry is barely capable of getting us around the Earth-Moon system and sending probes to the outer planets- the energy available per pound of rocket fuel isn't that large compared to interplanetary speeds.

So if you have fairly mature spacecraft technology, it is necessarily running on nuclear power sources or some form of (what is to us today) technomagic. And a chemical explosive just isn't that threatening compared to what happens when the nuclear-level energies that power the ship are turned into a weapon of some kind.

[Lord Revan]

I'm not talking about attacking shuttles with one missle, I'm talking about attacking cruisers with missle swarms of hundreds.

Even worse. This 'cruiser' will presumably have a solid layer of some kind of armor plating covering its entire hull.

Think. Spacecraft have to hold an atmosphere inside themselves- that's fourteen pounds of force per square inch of hull, pressing outward. How do you propose to seriously threaten that by applying LESS pressure from the outside of the hull? That won't even cancel out the interior pressure actively trying to tear the hull apart from inside, let alone exert meaningful crushing force.

A thin, pressurized shell (like a modern space shuttle) could conceivably be destabilized and crushed by external pressure... but your 'thermobaric' weapons are very poorly suited to supplying that pressure.

And against a well armored hull that is presumably designed to survive impacts from high-velocity kinetic rounds or high-energy beam weapons? Not even worth thinking about what would happen.

just in case Corvus isn't from a country that uses the imperial units that pressure is about 1 bar or 105Pa and 1 Pascal =1 N/m2, oh and 1 psi=6.894757 kilopascals

and that's ignoring any resistance from the hull itself. To use a Star Trek example your weapon would not even penetrate the Navigational Deflectors and not that's not (totally) a joke at the expense typical trekkie fanatic argument about how their ships are immune to anything with word laser at its name, but rathers it's what the Nav Deflectors were designed to do to counter the disperse gas and dust that's present in interstellar space sure the force normally is from the ship itself moving at high STL or warp speeds but in space motion is relative so it should just fine against a gas cloud moving towards it instead. Sure there's limits but this weapons isn't even close to those limits.

[Sky Captain]

Yeah, if you are shooting a big expensive missile at someone better put a nuke on it to make it do some real damage or even better if your technology allows a nuclear bomb pumped laser warhead to gain a standoff attack distance that would be plainly impossible with any kind of chemical warhead. At the speeds that would be tipically encountered during space combat a simple dumb kinetic impactor would do far more damage than any chemical explosive.

[Corvus 501]

Oh well, it's just a thought. Most brainstorms fail anyways, the idea was that thermobaric weapons would be cheaper to use than nukes.

[Purple]

Oh well, it's just a thought. Most brainstorms fail anyways, the idea was that thermobaric weapons would be cheaper to use than nukes.

That's debatable as well. The cost of atomic weapons is mostly in the payload, as in the enriched uranium. But a civilization that can afford to fight wars in space can certainly afford to enrich as much of the stuff as they want. Contrastingly the real cost of any space weapon is going to be in the delivery system. You either need a really fancy gun that can track the target and accelerate shells with a lot of force or guided missiles of astounding maneuvering capabilities. So the warhead cost will probably be minimal by comparison.

[Lord Revan]

Oh well, it's just a thought. Most brainstorms fail anyways, the idea was that thermobaric weapons would be cheaper to use than nukes.

That's debatable as well. The cost of atomic weapons is mostly in the payload, as in the enriched uranium. But a civilization that can afford to fight wars in space can certainly afford to enrich as much of the stuff as they want. Contrastingly the real cost of any space weapon is going to be in the delivery system. You either need a really fancy gun that can track the target and accelerate shells with a lot of force or guided missiles of astounding maneuvering capabilities. So the warhead cost will probably be minimal by comparison.

I suspect that most civilizations capable of at the very least semi-trivial space flight would probably also use fusion warheads instead of fission ones further reducing the cost of the warhead.

[Alyrium Denryle]

Oh well, it's just a thought. Most brainstorms fail anyways, the idea was that thermobaric weapons would be cheaper to use than nukes.

Nope. As Purple mentioned, nukes are expensive because the uranium/plutonium is expensive to mine, refine/make etc. But any civilization that fights wars in space has an advanced scientific infrastructure and the refining can be done on the cheap, and there are rather plentiful supplies once you control multiple solar systems.

Most of the expense is going to be in the delivery system, and the design process. You have to have targeting and tracking systems that can hit targets making evasive maneuvers from loooooong ranges, that have enough reaction mass to generate sufficient Delta V to make course changes (which limits your payload due to inertial considerations), all while being small enough that you dont start running into positive feedback loops with fuel mass and permitting storage of a sufficient quantity of them to get past the point defense lasers/slug throwers that will inevitably crop up to intercept them (which is another reason your proposal would never work. You would never connect with the hundreds of bombs in the configuration necessary to make the weapon effective, even if you could do it theoretically)

You have to design and manufacture those. The materials might be cheap, but the actual construction is not. Labor, maintaining the infrastructure etc. Shit's expensive. You want as much bang for the buck as possible in the warhead, and for that there is no substitute for a fission bomb. If you need a really big bang, go for a Teller-Ulam configuration fission-fusion device.