Super High Altitude Research Project - Design and Operation

Design and Operation

Rather than a single straight barrel, the SHARP gun is actually of an L-shape design comprising 2 separate sections—a 270 ft (82 m) long steel combustion section & pump tube, and a 155 ft (47 m) long launch tube (or barrel)—joined together at a right angle. At each end of the pump tube, there sits a 100-ton rail-mounted sled to absorb recoil energy from firing. A smaller 10-ton sled is also mounted on a set of tracks at the aft-end of the launch-tube near the junction point.

The firing sequence begins with the ignition of a methane gas mixture in the combustion section at the far end of the pump tube, which has been filled with pressurized hydrogen gas. The resultant explosion drives a 1-ton steel piston down the pump tube towards the junction point, rapidly compressing the hydrogen gas in the pump tube to a pressure of 60,000 psi (4,100 atm). Meanwhile, a small projectile rests in the adjacent depressurized launch tube. As the hydrogen gas reaches maximum pressure, a coupling holding the projectile in place is destroyed, driving the projectile down a 4-in diameter barrel at extremely high velocities until it bursts through a thin plastic sheet covering the end of the gun. All recoil forces are absorbed by the rail-mounted sleds as they are propelled outwards along their tracks.