NASA Test Flies Decelerator Designed for Mars Landings

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SAN FRANCISCO — New NASA gear that could help humanity set up an outpost on Mars has gotten its first test flight.

The space agency launched its Low-Density Supersonic Decelerator (LDSD) test vehicle June 28 from Hawaii. Although the first part of the test went well, the vehicle’s huge parachute apparently failed to deploy properly — but LDSD engineers are pleased anyway. 

“We are thrilled about yesterday’s test,” Mark Adler, LDSD project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement June 29. “The test vehicle worked beautifully, and we met all of our flight objectives. We have recovered all the vehicle hardware and data recorders and will be able to apply all of the lessons learned from this information to our future flights.” 

The test — which lifted off from the U.S. Navy’s Pacific Missile Range Facility on the island of Kauai at 8:45 a.m. local time — was designed to help NASA engineers get their first good look at how equipment designed to slow the descent of heavy spacecraft through the red planet’s atmosphere performs at high speeds in Mars-like conditions. 

The flight was originally scheduled for June 3, but poor weather conditions pushed it back multiple times.

The LDSD project is developing and testing a 30.5-meter-diameter parachute — the biggest supersonic chute ever flown — and two saucer-like devices called Supersonic Inflatable Aerodynamic Decelerators, or SIADs.

One SIAD is 6 meters wide, while the other measures 8 meters across. Both devices are built to fit around the rim of atmospheric entry vehicles like the one that carried NASA’s Mars rover Curiosity in August 2012, slowing them down by increasing their drag. 

During the test, a huge balloon carried the 3,175-kilogram test vehicle, which was equipped with the big chute and the 6-meter SIAD, to an altitude of 37 kilometers. The balloon dropped the craft at that point, and its onboard rocket motor kicked on, boosting it to Mach 4 — four times the speed of sound — and 55 kilometers high if all went according to plan.

The thin air at such heights is a good analog for the martian atmosphere, which is just 1 percent as dense as that of Earth at sea level, researchers said.

Had the test gone perfectly, the SIAD would have inflated and slowed the test vehicle down to Mach 2.5, at which point the chute would have deployed and taken the craft down to a soft splashdown in the Pacific Ocean.

But things did not go perfectly. The balloon dropped the test vehicle and the rocket appeared to fire properly. The SIAD seemed to inflate as planned, but data indicate that the parachute did not deploy correctly, officials said. More information will become available later, after engineers have had a chance to analyze data from the test.

The LDSD vehicle splashed down and was retrieved, along with the big parachute, by a recovery boat.

At about 900 kilograms, the SUV-sized Curiosity rover is the biggest spacecraft ever to touch down on Mars. The robot landed softly thanks to a bold and complicated scheme that involved a 15.5-meter parachute and a rocket-powered skycrane, which lowered Curiosity to the surface on cables.

The skycrane can (and probably will) be used again to put payloads down on Mars. But new gear such as bigger chutes and SIADs will likely have to be included to slow really heavy stuff down enough for the skycrane to finish the job, said Ian Clark, principal investigator on the project at the Jet Propulsion Lab. And that is where the LDSD project comes in.

NASA plans at least two more flight tests out of Hawaii, both of which will likely happen in 2015.