What photon torpedoes SHOULD have been...

[Patrick Degan]

In two threads on the Pure Star Trek and Star Trek v. Star Wars boards, the nature of photon torpedoes has cropped up in discussion. We know, of course, that the photon torpedo is essentially a missile with a matter/antimatter warhead. So named because, in the 60s, it was thought that the product of a M/AM blast would be pure gamma ray photons. That's not quite the case, of course, but the colliqualism persists not only for photorps but the more exotic forms of nuclear photonic rocket designs which are based on matter/antimatter anihilation as the propulsion source.

The friendly folks at Atomic Rocket have demonstrated why you'd never get 100% yield from an M/AM intermix in a warhead design. Lots of people go with the STNG/STDS9 tech manual assumption (though not supported in any actual episode) that a photorp warhead would produce the equivalent blast of a 64 MT nuclear warhead, a bit more than the yield measured for Tsar Bomba, the largest test detonation in history. According to the Atomic Rocket folks, if you could fuse one gram of matter and one gram of antimatter under conditions of 100% efficiency, you'd ideally get an energy yield equivalent to a 43 KT atomic bomb. Not bad if you can make it work.

Unfortunately, various factors ensure that you'd be lucky to get about 70% of that at most, which would still give you a respectable 30KT blast. The more pessimistic estimates downgrade the figure to a mere tenth of that yield for a 3KT blast, roughly the equivalent of a World War II blockbuster bomb. You're still getting much more bang for the buck, since you're using only a tiny fraction of the explosive material you'd need for a blockbuster bomb or a standard atomic bomb.

The problem of course is that you have to keep that 1kg of antimatter safely bottled up longterm until you're ready to fire your torpedo. Which leads to problems of its own. With a starship's full-load arsenal, you're talking about keeping 250kg of antimatter stored up outside the ship's standard fuel bunkers for a long period of time. Of course, it's been suggested that the antimatter is drained from the ship's own reserves and loaded into the warheads prior to combat. Which means a complex piping system to feed the antimatter into the warheads —which can break down or suffer battle damage, which neutralises the rest of your photorp arsenal. Which in a battle situation would be bad.

However, suppose for a moment that, instead of using the antimatter as reactant for the warhead it was instead used for propulsion and your torpedo, instead of an active weapon system, is actually nothing more than a 100kg trashcan-sized slug with a small-scale M/AM photonic rocket at the one end? The torpedo would be ejected out of a starship's tube, after which the engine would fire up, accelerating the 100kg mass very rapidly (say, a one second burst) to a velocity of 3000 km/sec. In this conception the torpedo is nothing more than a hypervelocity kinetic-kill missile.

A 100kg object impacting a solid target (or presumably a deflector shield) at 3000 km/sec would produce a force equivalent to a 107kt nuclear blast, which is about equivalent to the W-76 warhead carried by a Trident II SLBM. The antimatter to fuel the missiles could be contained in the rocket's own storage bottle, which would be plugged into the ship's general power grid for maintenance until it's time to load the tubes for the first salvo. A short-life battery would maintain the containment for only a matter of a minute or two, but you want that anyway when the torpedo is clear of the ship.

A fuel load of 400-600 micrograms of M/AM would be sufficient for this type of torpedo, constituting a far more logical usage for antimatter than in a warhead. Of course, this would mean the writers could never realistically use the photon torpedo as a mine or a "space depth charge". Instead, they could have shown a starship carrying a rather large arsenal (apart from its phasers) with the equivalent destructive power of about twenty present-day Trident SSBNs by employing a fairly basic brute-force principle instead of technobabble.

[Bounty]

The antimatter to fuel the missiles could be contained in the rocket's own storage bottle, which would be plugged into the ship's general power grid for maintenance until it's time to load the tubes for the first salvo. A short-life battery would maintain the containment for only a matter of a minute or two, but you want that anyway when the torpedo is clear of the ship.

You bring up the (valid) problems of containment and fuel transport as criticism of an M/AM torpedo and then you suggest this? Why not just go with conventional fuel then?

[Dominus Atheos]

According to the Atomic Rocket folks, if you could fuse one gram of matter and one gram of antimatter under conditions of 100% efficiency, you'd ideally get an energy yield equivalent to a 43 KT atomic bomb. Not bad if you can make it work.

Do you mean one gram, or one kilogram?

[Imperial Overlord]

According to the Atomic Rocket folks, if you could fuse one gram of matter and one gram of antimatter under conditions of 100% efficiency, you'd ideally get an energy yield equivalent to a 43 KT atomic bomb. Not bad if you can make it work.

Do you mean one gram, or one kilogram?

gram.

[mr friendly guy]

Can the hypervelocity missle also can be used to explain why we don't get missile interceptors in Trek? To elaborate what if photon torpedoes just move too, so AQ powers have simply opted for stronger shields as opposed to interceptors.

[Imperial Overlord]

Can the hypervelocity missle also can be used to explain why we don't get missile interceptors in Trek? To elaborate what if photon torpedoes just move too, so AQ powers have simply opted for stronger shields as opposed to interceptors.

Easily. If you're expecting to be hit with extremely hard to intercept hypervelocity missiles and impossible to intercept beam weapons, having strong shields which is a good defence against both weapons makes more sense than having a mediocre shield system and a low success interception system.

[montypython]

It may be possible to store anti-matter as a matter-based precursor, similar to how lithium hydride can be converted via fission reaction to tritium.

[Patrick Degan]

The antimatter to fuel the missiles could be contained in the rocket's own storage bottle, which would be plugged into the ship's general power grid for maintenance until it's time to load the tubes for the first salvo. A short-life battery would maintain the containment for only a matter of a minute or two, but you want that anyway when the torpedo is clear of the ship.

You bring up the (valid) problems of containment and fuel transport as criticism of an M/AM torpedo and then you suggest this? Why not just go with conventional fuel then?

Size and mass penalties for a start. Keep in mind that this application involves storing antimatter only in microgram amounts per each missile. For a full load of (being generous) 2500 torpedoes (each the size of a small trashcan), the entire antimatter storage for the lot would amount to only one kilogram. The idea here is that each torpedo in storage would be plugged into the ship's electrical grid to maintain the containment bottles and even would be plugged in while in the launch tube until the moment of firing. Once clear of the ship, it's not a problem.

[Arrow]

It may be possible to store anti-matter as a matter-based precursor, similar to how lithium hydride can be converted via fission reaction to tritium.

Can you elaborate on that a little more, please?

[Batman]

It may be possible to store anti-matter as a matter-based precursor, similar to how lithium hydride can be converted via fission reaction to tritium.

Can you elaborate on that a little more, please?

Seconded. I'm very eager to hear how that is supposed to work.

[The Silence and I]

I haven't a clue what HE means, but IIRC starships carry matter --> antimatter converters. Perhaps it might be feasible to install such a device in the torpedo bay and arm on the fly so to speak?

[Batman]

I haven't a clue what HE means, but IIRC starships carry matter --> antimatter converters. Perhaps it might be feasible to install such a device in the torpedo bay and arm on the fly so to speak?

No evidence for that past the non-canon TNG TM that I'm aware of and even that states the process is inefficient like nobody's business.

[The Silence and I]

I haven't a clue what HE means, but IIRC starships carry matter --> antimatter converters. Perhaps it might be feasible to install such a device in the torpedo bay and arm on the fly so to speak?

No evidence for that past the non-canon TNG TM that I'm aware of and even that states the process is inefficient like nobody's business.

As I recall TOS has stated their energy reserves regenerate, I expect this is from collecting hydrogen and using fusion to power such a converter (since they run on antimatter and you can't just pick that stuff up willy nilly in deep space). I doubt anyone can really speak to its efficiency as the TM as you rightly point out is non-canon.

Anyway, this is speculation on an alternate universe torpedo design...

[Batman]

(since they run on antimatter and you can't just pick that stuff up willy nilly in deep space)

As of VOY yes you can, apparently.

[Patrick Degan]

Anyway, this is speculation on an alternate universe torpedo design...

Actually, it's speculation on a more logical torpedo design.

[The Silence and I]

(since they run on antimatter and you can't just pick that stuff up willy nilly in deep space)

As of VOY yes you can, apparently.

*Waves Hand* No you can't.

[montypython]

Lithium can be converted into tritium via transmutation reactions, this is how lithium hydride can be used in nuclear warheads as a fusionable fuel instead of tritium in Tellar-Ullam designs.

A similar concept could be applied to materials within the 'island of stability' for transuranium elements to convert them via radiation bombardment into anti-matter.

http://www.milnet.com/nukeweap/Nfaq12.html
http://cat.inist.fr/?aModele=afficheN&cpsidt=1753825
http://www.osti.gov/bridge/servlets/pur ... 768622.pdf

[Steel]

With the trash can bottle rocket design, how exactly do they ensure that the exhaust isnt actually more of a threat to them than the missile is to the enemy?

[Patrick Degan]

With the trash can bottle rocket design, how exactly do they ensure that the exhaust isnt actually more of a threat to them than the missile is to the enemy?

One method would be to fire the torpedo off-axis so it clears the ship until its engine actually fires. The ship could also be moving at a tangent to increase it's vector away from the exhaust path of the photonic rocket. The time-delay between torpedo firing and engine start-up would also eliminate the nasty problem of recoil from an object suddenly accelerating to a velocity of 3000 kps.

[Gil Hamilton]

One method would be to fire the torpedo off-axis so it clears the ship until its engine actually fires. The ship could also be moving at a tangent to increase it's vector away from the exhaust path of the photonic rocket. The time-delay between torpedo firing and engine start-up would also eliminate the nasty problem of recoil from an object suddenly accelerating to a velocity of 3000 kps.

However, the problem is that once you fire your antimatter in a burst like that as rocket fuel, then you've got the problem of what happens when the target moves. Your design doesn't sound particularly high in delta-v after the initial thrust.

Further, it contains the same problem you have when you use antimatter as a warhead. You still have to keep the antimatter bottled up and you still need a transport system to move the fuel from storage to the rocket, which could still be damaged. Using the antimatter as fuel instead of as a warhead doesn't change that.

[Patrick Degan]

One method would be to fire the torpedo off-axis so it clears the ship until its engine actually fires. The ship could also be moving at a tangent to increase it's vector away from the exhaust path of the photonic rocket. The time-delay between torpedo firing and engine start-up would also eliminate the nasty problem of recoil from an object suddenly accelerating to a velocity of 3000 kps.

However, the problem is that once you fire your antimatter in a burst like that as rocket fuel, then you've got the problem of what happens when the target moves. Your design doesn't sound particularly high in delta-v after the initial thrust.

The target would have to have a better acceleration than 3000kps in one second to evade the torpedo or be an inordinate distance away to evade the strike.

Further, it contains the same problem you have when you use antimatter as a warhead. You still have to keep the antimatter bottled up and you still need a transport system to move the fuel from storage to the rocket, which could still be damaged. Using the antimatter as fuel instead of as a warhead doesn't change that.

You do not need to transport the fuel to the rocket: it would already be bottled up and ready for firing. The antimatter would also be in microgram amounts as opposed to kilograms, which considerably lessens the storage problem. Thirdly, the torpedo's antimatter bottles would remain plugged into the ship's general power grid to maintain the containment fields until firing.

[Darth Wong]

To be honest, I don't like antimatter missiles at all. If I were writing a sci-fi series with Trek-level technology from the ground up, I'd make them either use a low-mass "forced singularity" (since we know they can make those) for the warhead or an inertial-confinement fusion device. In both cases, there is no need to worry about piping or confining volatile reactants prior to arming the warhead.

Think about it- if you can make a forced singularity and launch it at somebody along with a sustainer, then it will automatically detonate when the sustainer either runs out of power or is destroyed. It will also release all of its mass/energy as X-rays. And before you turn this thing on, it's inert. No hazardous storage concerns.

The fusion idea is a bit more pedestrian, but it works too. If you can generate the necessary conditions without a fission trigger, then most of the practicality issues of nuclear weapons are removed.

[Gil Hamilton]

The target would have to have a better acceleration than 3000kps in one second to evade the torpedo or be an inordinate distance away to evade the strike.

3000 kilometers isn't that much in terms of distance in space. Your weapon would be a good close range weapon, but at a certain point, you'd be lucky to hit anything with it unless they were right next to you, cosmically speaking.

You do not need to transport the fuel to the rocket: it would already be bottled up and ready for firing. The antimatter would also be in microgram amounts as opposed to kilograms, which considerably lessens the storage problem. Thirdly, the torpedo's antimatter bottles would remain plugged into the ship's general power grid to maintain the containment fields until firing.

You can apply the same logic to antimatter warheads. You can put a bit of antimatter (not necessarily kilograms of the stuff, since a kilogram of liquid hydrogen is 14.3 liters of the stuff, liquid H2 is very light) in the warhead and plug it into the general power grin ther same way, and just store the anti-matter for the warhead in the torpedo. There is no reason why you can't store the antimatter for the warhead in the torpedo if you can store antimatter for the propulsion system in the torpedo.

[Patrick Degan]

The target would have to have a better acceleration than 3000kps in one second to evade the torpedo or be an inordinate distance away to evade the strike.

3000 kilometers isn't that much in terms of distance in space. Your weapon would be a good close range weapon, but at a certain point, you'd be lucky to hit anything with it unless they were right next to you, cosmically speaking.

And since we mostly see photorps being applied as mainly short-range weapons... what's your point, exactly? You're also forgetting it's other tactical application as an orbital bombardment weapon.

You do not need to transport the fuel to the rocket: it would already be bottled up and ready for firing. The antimatter would also be in microgram amounts as opposed to kilograms, which considerably lessens the storage problem. Thirdly, the torpedo's antimatter bottles would remain plugged into the ship's general power grid to maintain the containment fields until firing.

You can apply the same logic to antimatter warheads. You can put a bit of antimatter (not necessarily kilograms of the stuff, since a kilogram of liquid hydrogen is 14.3 liters of the stuff, liquid H2 is very light) in the warhead and plug it into the general power grin ther same way, and just store the anti-matter for the warhead in the torpedo. There is no reason why you can't store the antimatter for the warhead in the torpedo if you can store antimatter for the propulsion system in the torpedo.

Oh, on that I agree. It's how I'd design the photorp system on my starship in either application. The difference is one of material efficiency: 400-600 micrograms of antimatter to propel a 100kg slug to 3000kps which packs a 107kt punch on impact with a solid target or a forcefield v. 1g of antimatter for a 30kt warhead in addition to the fuel requirement for a larger torpedo which takes up more storage space aboard the ship.

[RedImperator]

The target would have to have a better acceleration than 3000kps in one second to evade the torpedo or be an inordinate distance away to evade the strike.

3000 kilometers isn't that much in terms of distance in space. Your weapon would be a good close range weapon, but at a certain point, you'd be lucky to hit anything with it unless they were right next to you, cosmically speaking.

You could get around that problem by making the warhead the final stage of a multi-stage missile. That also gets around the problem of the exhaust and the recoil of the antimatter powered terminal stage. The kinetic kill vehicle isn't very large, so a missile carrying it wouldn't have to be huge.