What will it take to land heavier spacecraft on Mars? How will engineers slow large payloads traveling at supersonic speeds in a thin Martian atmosphere? The Low Density Supersonic Decelerator (LDSD) mission will seek to answer these questions.

A saucer-shaped test vehicle at the U.S. Navy's Pacific Missile Range Facility in Hawaii. (NASA/JPL-Caltech)

NASA scientists and engineers borrowed a technique used by the Hawaiian pufferfish called Rapid inflation. For the pufferfish, it is simply a defense mechanism. For NASA, it is potentially the element that links to the future of space exploration. LDSD will use a 20-foot-diameter, solid rocket-powered, balloon-like vessel called a Supersonic Inflatable Aerodynamic Decelerator (SIAD) to test these capabilities.

A helium-filled scientific balloon will lift the massive test article to 120,000 feet. At that altitude, the test article will be detached from the balloon and a solid rocket motor will be employed to boost the test article on a trajectory to reach supersonic speeds (Mach 4) needed to test the SIAD. Once at supersonic speeds, the deployment and function of the inflatable decelerators will be tested to slow the test article to a speed where it becomes safe to deploy a supersonic parachute.