Two Russian cosmonauts at the International Space Station spent six hours in space Wednesday to retrieve an explosive bolt believed the cause of the Soyuz spacecraft's dangerously high-speed descent and landing on two recent missions, NASA said.
While US flight engineer Greg Chamitoff monitored the spacewalk from inside the Soyuz capsule, ISS Commander Sergei Volkov and Flight Engineer Oleg Kononenko attached themselves to the Strela hand-powered crane outside the ISS and Volkov was maneuvered to the Soyuz.
They cut back insulation to safely get to the pyro bolt, which was then secured in a protective blast-proof case to be sent back to Earth for examination.
The risky operation required them to first remove the electrical cables that fire the bolts, to avoid sparking a firecracker-sized explosion that could damage their space suits.
"It's in, thank God," one of the astronauts said when they had secured the bolt, the Houston Chronicle reported.
Russian space officials believe that the pyro bolts, which help separate the Soyuz from its docking position ahead of its trip back to Earth, were failing to operate correctly.
These failures, they suspect, caused the Soyuz to enter the atmosphere at an incorrect angle and excessive speeds on the two most recent missions, on October 21, 2007, and April 19 this year.
The off-track re-entry subjected the cosmonauts to uncomfortably high G forces, and also caused the spacecraft to land heavily hundreds of kilometers (miles) off course.
