Spacewalk Retrieves Explosive Bolt

Two cosmonauts at the International Space Station conducted a spacewalk on Thursday and performed the delicate operation of removing an explosive bolt from the Soyuz capsule attached to the station. Ten explosive bolts in all on the Soyuz break the connections between the spacecraft’s crew capsule and its propulsion module during descent back to Earth. Engineers suspect one bad bolt delayed the compartment’s jettison during landings in October 2007 and April 2008, leading to steep, high-G descents, causing the capsule to land off-course and hit the ground harder than it should. Sergei Volkov and Oleg Kononenko removed the bolt located in the same spot as the ones diagnosed as being faulty on the other capsules. They placed it inside a blast-proof canister, which will be returned home aboard the Soyuz when the crew completes its mission in October.

The spacewalk took 6 hours and 18 minutes to complete. US astronaut Greg Chamitoff remained in the Soyuz during the spacewalk, part of the contingency plan for the unlikely event the Pirs airlock could not be repressurized. Otherwise he would not have had access to the station’s lifeboat through a depressurized Pirs. “We do not like to separate the crew from (the) escape vehicle,” flight director Bob Dempsey told reporters in a briefing last week. “Therefore Greg will be staying in there. He will have some laptops, books and computers to work on while he’s there.”

Although engineers assured the bolt would not denoted, Russian mission control repeatedly told the cosmonauts to go slow and take their time. About halfway into the spacewalk, the bolt had been removed and placed in the container. “Good! Thank God, it is in,” one cosmonaut exclaimed. Mission control then told the cosmonauts to take a five minute break “without any motions, without moving,” before moving on to complete their tasks.

Chamitoff will have another stay in the Soyuz next Tuesday, as Volkov and Kononenko will conduct another spacewalk on July 15 to outfit the Russian segment’s exterior, install one scientific experiment and retrieve another.

News Sources: NASA, NASA TV