NASA recently performed a trial run on a rocket sled test fixture, powered by rockets, to replicate the forces a supersonic spacecraft would experience prior to landing. The sled tests will allow the Low-Density Supersonic Decelerator Project, or LDSD, to test inflatable and parachute decelerators to slow spacecraft prior to landing and allow NASA to increase landed payload masses, improve landing accuracy and increase the altitude of safe landing-sites. These new devices represent the first ste