Recovery of high-performance re-entry vehicles by drag brakes plus parachutes.

Abstract

A ballistic re-entry vehicle with a high ballistic coefficient encounters severe aero thermal nose-cap environments whose maximums occur at very low altitudes for steep re-entry trajectories. To obtain quantitative measures of heat-shield material's performance for such vehicles, flight tests achieving maximum dynamic pressures in excess of 160,000 psf are mandatory. There has been a strong desire to recover these test vehicles via airsnatch or low-speed impact on water or land without either 1) imposing large, impractical weight and complexity penalties on the vehicle to achieve the necessary deceleration forces or 2) compromising the test environments. A solution to this problem is to use a combination of structural hypersonic drag brakes and parachutes. Preliminary wind-tunnel tests have shown the drag brake concept to be practical. Both subsonic and supersonic parachutes were considered and their effects on the total system capability were identified. Analysis shows that subsonic parachute systems could be used with only a small penalty in achievable flight-test environments.