scope:

Abstract:

The Dryden Aerospike Rocket Test Director's Discretionary Fund (DDF) project conducted flight research of an aerospike rocket nozzle design using high power amateur rockets. The standard nozzles in these rockets were replaced by the aerospike nozzles and the rockets are then flown with aerospike nozzles only. Two aerospike rockets were flown successfully to altitudes of over 26,000 ft and speeds of over Mach 1.5. The flight data acquired during the flight tests were stored onboard and retrieved after the rockets were recovered. The rockets were recovered using a dual-stage parachute system. The smaller drogue chute comes out at rocket apogee to stabilize the rocket. The main chute deploys at approximately 2500 ft above ground level to slow the rocket descend for a soft impact on landing. During the first rocket launch, the main chute deployed inadvertently when the drogue chute activated, and the rocket descended on the main chute from apogee. During the second rocket launch, the main chute bag got outside of the rocket airframe and was entangled with the main chute retention line, preventing main chute deployment and causing the rocket to descend under drogue chute only. Both of these problems were caused by excessive slack in the main parachute retaining line.