NASA’s Supersonic Decelerator Test

Image Credit: NASA

Update: NASA has once again postponed the LDSD test due to high waves in the recovery area. The next window opens tomorrow, June 4th, at 7:30 AM HST (1:30 PM EDT).

Last year, NASA conducted the first of series of tests of a new method for landing larger payloads on Mars. The June 28th, 2014 test of the agency’s Low-Density Supersonic Decelerator (LDSD) project was mostly successful, however the final elements of the event, the deployment of the Supersonic Discsail Parachute did not go as planned.

NASA second test article is now at the Pacific Missile Range Facility on the island of Kauai. Hawaii, for a 10 day flight window which opened on June 1st, but did not see a liftoff due to high seas in the recovery area. As before, an extremely high altitude balloon will lift the rig to approximately 120,000 feet, at which point a solid rocket motor will ignite and push it to 180.000 feet and Mach 2.5.

There, in conditions which are a simulation of a part of a Mars atmospheric descent profile, the first of two separate elements will deploy. Called the Supersonic Inflatable Aerodynamic Decelerator or (SIAD), it consists of an inflatable donut shaped ring surrounding the test article.  Once inflated, the ring serves to increase the total surface area and thus its drag, letting Mars’ vanishingly thin atmosphere shoulder some of the load.

As it slows to roughly Mach 2.35, the massive supersonic parachute, which was redesigned after last year’s partial failure, will then fully deploy, slowing the craft to the point at which an incoming Mars payload could then use its chemical engines for the final descent and touchdown.

The potential payoffs of the new approach are significant. In addition to doubling a lander’s mass from the current upper limit of 1.5 tons, it could also dramatically improve the targeting ellipse from 6.5 miles to approximately 1 mile. Equally important, if perfected this technique could allow landers to touch down on much of the planet’s surface which is currently inaccessible due to the fact that atmosphere is too thin at higher elevations to provide the drag needed to slow down.

The next flight window opens tomorrow morning, June 3rd at No Earlier Than (NET) 7:30 AM HST, 1:30 PM EDT.

NASA commentary will be carried on NASA TV, as well as on its website at and on ustream at

The LDSD project is funded by NASA’s Space Technology Mission Directorate, led by JPL and managed by the Marshall Space Flight Center.

Posted in: Mars, NASA

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