CAPE CANAVERAL - A helium balloon carrying an experimental saucer-shaped NASA spacecraft floated off a launch tower at the U.S. Navy's Pacific Missile Range Facility in Kauai, Hawaii, on Saturday to test landing systems for future missions to Mars.
A novel inflatable shield to burn off speed worked but the test fell apart when a massive parachute, intended to guide the saucer to a splashdown in the ocean, failed to inflate properly.
"This is an opportunity for us to take a look at the data, learn what happened and apply that to the next test," NASA engineer Dan Coatta, with the Jet Propulsion Laboratory in Pasadena, California, said during an interview on NASA Television.
"That's a more valuable experience for us than if everything had gone perfectly," he said.
The balloon - big enough to fill the Rose Bowl football stadium in Pasadena, California - lifted off at 2:40 p.m. EDT (1840 GMT) and reached its designated altitude 120,000 feet (36,576 meters) above the Pacific Ocean about 2.5 hours later.
The launch, which had been delayed six times this month because of unsuitable weather, and the test were broadcast live on NASA Television.
The saucer-shaped Low Density Supersonic Decelerator, or LDSD, successfully separated from the balloon and fired up its rocket motor, reaching speeds of 3,000 mph (4,828 kph) - roughly four times the speed of sound.
That set the stage for the real point of the test - collecting engineering data on a novel doughnut-shaped structure designed to quickly unfold, inflate and slow the craft's descent. The LDSD also held a massive supersonic parachute - the largest NASA has ever tested - that was to guide the craft to a controlled re-entry into the Pacific Ocean.
The 110-foot-diameter (34-meter) parachute failed to properly inflate, however, engineers monitoring the test said.
Recovery teams were standing by to pick up all the equipment splashing down in the ocean.
The point of the test flight was to put a prototype landing system through conditions that would be experienced on Mars.
"When we're actually going to use it for real, it's going to be on a spacecraft, entering the atmosphere of Mars at thousands of miles per hour, so we have to come up with some way on Earth to simulate that condition in order to prove that these things work," Coatta said.
The test is part of a larger technology-developing initiative to prepare to send heavier rovers and eventually human habitats to Mars.
NASA is spending about $200 million on the five-year project, which began in 2010. LDSD's next test is scheduled for next summer.