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Apr. 26th, 2002 06:49 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
pargentumJules Verne Launcher
No gun projectile can exceed the velocity of the propellant gases in the barrel. The light gas gun takes advantage of the fact that a lower molecular weight gas, such as hydrogen, has a higher velocity at a given temperature than the heavier molecules of conventional gun propellants. In order to heat the hydrogen up, a two-stage design was developed. A gas pump tube was set at a right angle to the gun barrel itself. Inside the pump tube was a piston. An explosive mixture of methane gas was ignited, pushing the piston down the tube, compressing and heating the hydrogen gas on the other side of the piston. When the pressure reached 4,000 atmospheres, a partition burst, releasing the gas into the gun tube, pushing the projectile down its length. As in the Oberth design, the barrel itself was depressurised and covered with a plastic lid to reduce drag against the projectile as it travelled down the barrel. Using this approach, Hunter felt that muzzle velocities of up to 7 km/sec could be obtained (compared to Bull's 2 km/sec). At this speed, a simple single-stage rocket stage would be sufficient to place a payload into orbit. The payload itself would amount to 66% of the launch mass.
No gun projectile can exceed the velocity of the propellant gases in the barrel. The light gas gun takes advantage of the fact that a lower molecular weight gas, such as hydrogen, has a higher velocity at a given temperature than the heavier molecules of conventional gun propellants. In order to heat the hydrogen up, a two-stage design was developed. A gas pump tube was set at a right angle to the gun barrel itself. Inside the pump tube was a piston. An explosive mixture of methane gas was ignited, pushing the piston down the tube, compressing and heating the hydrogen gas on the other side of the piston. When the pressure reached 4,000 atmospheres, a partition burst, releasing the gas into the gun tube, pushing the projectile down its length. As in the Oberth design, the barrel itself was depressurised and covered with a plastic lid to reduce drag against the projectile as it travelled down the barrel. Using this approach, Hunter felt that muzzle velocities of up to 7 km/sec could be obtained (compared to Bull's 2 km/sec). At this speed, a simple single-stage rocket stage would be sufficient to place a payload into orbit. The payload itself would amount to 66% of the launch mass.
