Everyone has heard of the famous nuclear test where scientists accidentally shot a drain cover out of the solar system, but few have considered the possible practical applications. This is much cheaper and faster than any ground mounted railguns, giant cannon, or even miles long acceleators, but it will certainly kill any people, or even electronics, in the projectile, and emit harmful fallout for those on the ground. What it is good for, however, is shooting alien invaders (or asteroids) who would do far more damage than the fallout from a single nuclear test. The applications of a solar escape-velocity hubcap are obvious against an alien enemy, but you may ask what good it would do against a kilometers wide asteroid. The solution: Don't shoot a drain cover. Instead, use a barely subcritical mass of plutonium surrounded with a much thicker layer of steel. No detonator is necessary: when it hits the alien spacecraft (or asteroid) the sheer impact performs the same function as the explosives in an ordinary plutonium bomb. this would act as a nudge to push it out of earths way. Because of the simplicity and inexpensiveness of the launch aparatus, many nukes could be shot at it, each with only a few kilotons of power, to avoid splitting it into multiple city-killers.

Advantages: proven concept, cheap, could be mobilised from our current state to shooting at aliens in a few days if need be.

Disadvantages: inaccurate until the first few shots are sufficiently modeled and learned from, fallout, name does not make cool acronym yet.
-- quadmaster, May 24 2010

Drain cover http://www.strangeh...21021/manhole.shtml
There you go. [nineteenthly, May 24 2010]

//Everyone has heard of the famous nuclear test where scientists accidentally shot a drain cover out of the solar system// No, nor do I buy it.

But in any case, this sounds like a EFP which using a nuke instead of a chemical high explosive, which is interesting, though doing it with Plutonium sounds INSANELY dumb. Do you think that launching explosion won't MASSIVELY bombard your projectile and trigger it? Also the idea of doing this from Earth is problematic as you mention, but doing it from the Moon or just deep space is interesting.

Is this baked by the original ORION project? Kind of but no. ORION was a rocket and yours is a cannon. I think you'd have to modify your idea in line with ORION to get it to work because I'm REALLY dubious that slamming a subcritical mass of plutonium into a solid object would detonate it as the pressure used for detonation is unbelievably precise and even all around the surface so that the pressure waves meet at the center, but my knowledge is decades old and faded, so I will let others weigh in on that.

I'm still on the fence on this.
-- MisterQED, May 24 2010


Sorta cool idea shooting a plasma stream through space at a healthy fraction of c, but the barrel would be destroyed long before (relatively speaking) the projectile had a chance to use it, and without that you'd never actually hit what you were aiming at. (Of course you could pretend that it was a "shot across the bows")

[edit] hmm... magnetic-containment barrel?

and I call bullshit on the draincover unless you can tell me how a chunk of steel can hit 42.1 km/sec and still be in pieces big enough to make it out of the atmosphere.

[edit] thanks [19thly], so by "drain cover" they magically mean a 1 ton steel cap, not a 50lb 2' dia manhole cover, and it's on top of a cement plug on top of a 500ft shaft.
-- FlyingToaster, May 24 2010


The draincover rumour is not true. I saw the maths on it and it wouldn't even have gone into orbit. I'll try to find a link.
-- nineteenthly, May 24 2010


//Everyone has heard of the famous nuclear test where scientists accidentally shot a drain cover out of the solar system// Nope, first time here for me, but then, I'm not everyone.
//sufficiently modeled//
Is that like "yodeled"?
-- coprocephalous, May 24 2010


Item one:

Ground launched "escape velocity" projectiles will not reach orbit due to atmospheric interference.

Item two:

Ground launched "super escape velocity" projectiles with sufficient speed to punch through the atmosphere will burn up in the atmosphere. There may be solutions to this, but they will not involve metals. Highly specialized ceramics might be possible, but even these are unlikely.

Item three: Slamming a sub-critical mass into an asteroid will not detonate it. One of the most difficult parts of building an implosion type nuclear weapon is the precise design of the explosives shell such that the mass compresses sufficiently uniformly to detonate.

So, put simply, this will not work for several different reasons.
-- MechE, May 24 2010


well...it 'would' be a flying disk.
-- 2 fries shy of a happy meal, May 25 2010


Thanks. I guess I hadn't checked my sources. Oh well
-- quadmaster, May 25 2010


Ah, but using an underground nuclear device to flash a body of water to steam, to in turn propel a primary launch vehicle out of a heavily reinforced barrel/cylinder, now that idea has legs.

The way I understand rocket physics (which is to say, poorly, and in general terms only), giving any initial velocity boost to a launch vehicle would massively lower the propellant/payload ratio required.
-- Custardguts, Jun 25 2012


Tragically, the lack of a cool acronym is probably a crippling disadvantage for this scheme. However, should you call it the Plutonium Utilising, Lethal Sphere Emitting Cannon (PULSE Cannon), I feel that the world could probably be your oyster...or any other form of shellfish according to preference, or quorn if you are a veggie.
-- DrBob, Jun 25 2012


//use a barely subcritical mass of plutonium surrounded with a much thicker layer of steel//
what if you put the Pu in oil in a piston/cylinder arrangement, so that the hydraulic pressure would be transferred evenly around the sphere?
-- AbsintheWithoutLeave, Jun 26 2012



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