Failed explosive devices designed to release two parachutes caused the crash of a space capsule carrying solar wind ions in Utah, say scientists from NASA's Genesis mission.
Blame for the failed explosions was settling on the capsule's battery, electronics, or sensors on Wednesday afternoon. In the evening, the 190-kilogram capsule - with its potentially dangerous live mortars - was successfully moved to a clean room at the US Army Dugway Proving Ground in Utah.
Some dirt has been removed and the Genesis team will begin examining the contents of the canister on Thursday, hoping to recover some science from the $264 million mission.
The capsule crash-landed in the US Air Force's Utah Test and Training Range at 1158 EDT on Wednesday when it failed to deploy its two parachutes.
"For whatever reasons, none of the pyros on board fired," said Bob Corwin at a NASA briefing. He heads the capsule's recovery operations for Lockheed Martin, which built the spacecraft. About six pyrotechnic devices are involved in deploying the drogue parachute, then the main parafoil, and finally separating the two, he said.
"The battery is a possible cause of not firing the initial pyros," he said. "Once you don't fire the first ones, you don't fire the rest of them." An overheating battery in the capsule was discovered running at about 40°C instead of the expected 23°C shortly after the spacecraft launched in August 2001. But Corwin said further tests had shown the batteries could still operate at even higher temperatures.
Deep impact
The problem could also have arisen in the electronics used to fire the pyros, or in the sensors that trigger them. Forty-five seconds after atmospheric entry, friction with the air was expected to decelerate the 11 kilometre-per-second craft rapidly, starting a timer. This timer should have fired a mortar to release the drogue chute about two minutes after atmospheric entry.
But the mortar never fired, and the capsule crashed to earth at an estimated 310 km per hour (193 miles per hour). That impact cracked open both the capsule and the science canister it housed by a few inches, said Roy Haggard, who inspected the crash site. He had flown in one of two helicopters meant to catch the capsule in mid-air by hooking onto its parafoil.
"We're sorry we didn't get to perform the mid-air retrieval we trained so hard for, but our hearts go out to the science team," Haggard said.
"This is not a complete loss of the mission," said Don Sevilla, the mission's payload team leader at NASA's Jet Propulsion Laboratory in Pasadena, California. He said workers would try to prevent any of the five fragile collector arrays from being further damaged while the canister was moved and opened.
Billion billion ions
Each array studies a different type of solar wind particle, blown out from the Sun, and has a unique thickness. So it may be possible to "reconstruct" the smashed arrays to salvage some data. The arrays collected more than a billion billion ions – it was hoped that this sample of the Sun would reveal the composition of the cloud that formed the solar system 4.5 billion years ago.
But Sevilla added: "The solar wind ions have been imbedded very shallowly, and it's going to take some time to develop techniques to ensure any contamination on the surface can be cleaned without hurting the science objectives."
A mishap review board composed of engineers and administrators will be appointed within 72 hours of the crash, said a NASA official. Their findings, which may take several months to report, will influence the design of future spacecraft intended to bring samples back from Mars or beyond.
But "the die is cast" for NASA's Stardust mission, which uses a similar design and has already been launched, said Chris Jones, director of Solar System exploration at JPL. Stardust will drop samples of a comet over Utah in January 2006.
"Let's hope this was an isolated failure and not a generic problem," says John Logsdon, director of the Space Policy Institute at George Washington University. "But how quickly we forget that nine months ago, we landed two rovers on the surface of Mars with parachutes and inflatable balls."
