"There is always some residual risk that something could go wrong on return, but we think that is very low at the moment," said Ed Hirst, Stardust's mission system manager.
In fact, the Stardust capsule could survive an impact even if its parachute does not open, its designers claimed.
"We know we can finish our science," said the project manager, Tom Duxbury.
Brownlee was equally confident. "It's a charmed mission," he said.
After landing, the capsule will be taken to the Stardust Laboratory at the Johnson Space Center in Texas, where its aerogel package will be broken open. Inside scientists expect to find about 1,000 grains from Wild 2. In total, the US$430 million probe will return about 1 milligram of comet matter, less than a thimbleful.
"Some scientific secrets will come out almost immediately," Brownlee said.
"Other things will take years. But we expect to get a significant scientific return within the first couple of months of investigation," he said.