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.
If the test had 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 at 5:05 p.m. EDT (2105 GMT), and the rocket appeared to fire properly. The SIAD seemed to inflate as planned, but data indicate that the parachute didn't deploy correctly, officials said. More information will become available later, after engineers have had a chance to analyze data from the test.
PHOTOS: Dragon's Bounty: SpaceX Mission Complete
The LDSD vehicle splashed down in the Pacific Ocean at 5:35 p.m. EDT (2135 GMT), NASA officials said. The craft and the big parachute were retrieved later Saturday by a recovery boat.
Getting Big Payloads Down on Mars At 1 ton, the SUV-size 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 51-foot-wide (15.5 m) parachute and a rocket-powered sky crane, which lowered Curiosity down to the surface on cables.