Summary of the second high-altitude, supersonic flight dynamics test for the LDSD project

NASA's Low-Density Supersonic Decelerator Project is developing and testing the next generation of supersonic aerodynamic decelerators for planetary entry. A key element of that development is the testing of full-scale articles in conditions relevant to their intended use, primarily in the tenuous Mars atmosphere. To achieve this testing, the LDSD project developed a new test architecture for the qualification of their supersonic parachute. A large, helium filled scientific balloon is used to hoist a 4.7 m blunt body test vehicle to an altitude of approximately 32 kilometers. The test vehicle is released from the balloon, spun up for gyroscopic stability, and accelerated to over four times the speed of sound and an altitude of 50 kilometers using a large solid rocket motor. Once at those conditions, the vehicle is despun and the test period begins. The second flight of this architecture occurred on June 8th, 2015. This flight sought to build on the very successful shakeout test of 2014 by testing an updated design of a new 30.5 meter nominal diameter supersonic parachute that applied lessons learned from the first flight. Two other supersonic decelerators were also tested: a 6 m diameter Supersonic Inflatable Aerodynamic Decelerator (SIAD), and a 4.4 m diameter trailing ballute. This paper summarizes the results from that test.