Ooopps... new space propulsion method

[GeneW]

A new kind of space propulsion by accident... also an example of some people thinking "big".

"he Pascal A nuclear test "launched" a blast door at six times earth escape velocity. Originally meant to test a safety feature on nuclear weapons instead it went... nuclear. Buried at the bottom of a 500 foot deep shaft the bomb detonated. A heavy steel door on top of the shaft was "lost" and some speculated was launched into outer space.

The asteroid and meteor FAQ explains how atmospheric resistance is a problem for small objects. If an object (round object like a meteor) is less than 8 tons then it loses all of its momentum and gets mostly destroyed trying to pass through the atmosphere at high speed. On the very large end of the scale, a meteoroid of 1000 tons (9 x 10^5 kg) would retain about 70% of its cosmic velocity. A 100,000 ton object passes through the atmosphere like it is not there.

Objects can only be propelled to very high velocities by a nuclear explosion if they are located close to the burst point. Once a nuclear fireball has grown to a radius that is similar in size to the radius of a quantity of high explosive of similar yield, its energy density is about the same and very high velocities would not be produced. This radius for a 300 ton explosion is 3.5 meters.

The steel plate at the top of the shaft was over 150 m from the nuclear device, much too far for it to be propelled to extreme velocity directly by the explosion. The feature of Pascal-B that made this possible was the placement of the collimator close to the device. The mass of the collimator cylinder was at least 2 tonnes (if solid) and would have been vaporized by the explosion, turning it into a mass of superheated gas that expanded and accelerated up the shaft, turning it into a giant gun. It was the hypersonic expanding column of vaporized concrete striking the cover plate that propelled it off the shaft at high velocity.



So we should try to size at that range for a nuclear launched projectile. Shaping the projectile like a bullet or rocket would also help.

90pct containment was proved by Pascal A dome, which did not get direct blast exposure but instead needs a rapid closing mechanism after projectile exit. 10pct blown into air should be 99pct contained within dome which sees NO direct heat radiation. There would be considerable secondary from the muzzle blast. So 99.9+ percent containment. 10 megaton blast say 15 kilograms tritium output all but 15 grams contained, if 5 kt fission (design a device with less fission and more fusion) then all but 5 tons of fission products contained! (fraction of 1 gram by weight)

There could be conventional explosives in the shaft to collapse the shaft after the launch projectile has passed."



Might work.. but I'd hate to have to clean up after it.

[Ferret_san]

Ummmm.... about a quarter past three.

[TLyttle]

Close... I figure Forty-Two...