London

The NASA solar-wind probe that crash-landed in the Utah desert last week was cunningly designed to deal with landing problems, mission planners say. But the jury is out on how much data can be saved.

“The prospects for our highest priority objectives are good, although we probably won't be able to do everything we wanted,” says Don Burnett, principal investigator on the Genesis project.

The US$260-million Genesis probe carried delicate wafers of gold, diamond, sapphire and silicon, designed to catch particles from the solar wind. The four plates of these wafers, which were exposed to different kinds of solar activity, were made of slightly different thicknesses. This was intended to help researchers reassemble the plates if a bumpy landing smashed them.

NASA arranged for highly trained helicopter pilots to snag the returning capsule after parachutes had slowed its return to Earth (see Nature 429, 340–342; 2004). Mission planners were fairly confident that damaged plates could be reconstructed if the parachutes worked but the pilots failed, leaving the probe to hit the desert at about 10 kilometres per hour.

Unfortunately, the parachutes themselves failed, and the probe smashed into the ground on 8 September at more than 200 kilometres per hour. “We have a mangled mass of a spacecraft,” says David Lindstrom, a Genesis programme scientist based at NASA headquarters in Washington.

Some of the detectors, including a concentrator designed to collect the densest sample of solar wind, seem intact. The impact smashed many of the wafers, however, and also ruptured the container, exposing some, if not all, of the detectors to Earth's air and soil — a much bigger problem for mission scientists.

But they remain optimistic, says Lindstrom. The atoms collected from the solar wind slammed into the detectors at hundreds of kilometres per second, so they should be buried 100–150 nanometres beneath the plate surfaces. It could therefore be possible to distinguish this tiny sample from contamination on the surface.

The mission debris was dug out of the desert and taken to a cleanroom at the Jet Propulsion Laboratory in Pasadena. The Genesis Mishap Investigation Board will try to determine what caused the failure. One possibility is a battery that should have sparked a small explosion to release the parachutes. Another NASA mission, Stardust, is relying on a similar parachute system for its return to Utah in 2006.