NASA scientists are looking for a nice, soft landing with the Stardust space probe returns to Earth in Utah's west desert next month.
At the least, they're hoping for a better landing on Jan. 15 than the 200 mph impact of the Genesis probe in September 2004. That mishap was blamed on gravity sensors having been installed backward.
"We feel very comfortable that we don't have any errors like the reversed (gravity) sensor for Genesis," said Thomas Duxbury, project manager for NASA's Stardust mission.
Stardust, which was launched in 1999, flew through the tail of the Wild 2 comet last year to collect some of the microscopic debris streaming from it.
Scientists believe comets preserve the solar system's original building material, and hope the Stardust samples could give insight into the processes involved in forming the sun, planets and other objects in the solar system.
Despite the Genesis crash, scientists managed to salvage much of the solar science from the Genesis collector equipment. The delicate nature of the Genesis collector plates, where solar particles became embedded, prompted engineers to design the softest possible landing. A helicopter was to have snagged the probe as it descended by parachute. But the parachute failed to open.
Stardust is to parachute to earth. Its collector material is sturdier than that of Genesis, making it better able to handle a parachute landing.
A major reason for optimism about Stardust's gravity sensors is the thorough review process scientists and engineers undertook during the mission. Design plans, photographs and reports indicate the sensors are properly installed and that everything else is up to specifications.
"There were no smoking guns. Everything was designed and implemented and tested correctly," Duxbury said.