Cosmonauts Remove Explosive Bolt From Soyuz Capsule

Even though mission controllers repeatedly asserted there was no danger... we're pretty sure everyone involved in a somewhat daring spacewalk outside the International Space Station Thursday, including the two cosmonauts who performed the extravehicular excursion, are quite relieved it's over.

During a four-hour exercise, cosmonauts Sergei Volkov and Oleg Kononenko successfully removed one of 10 explosive bolts used to separate the service section of their Soyuz TMA-11 space capsule, from the re-entry module. Malfunctioning separation bolts are suspected to have been behind problems with the last two Soyuz re-entries, both of which took dangerously steep paths in their returns from orbit.

Complicating matters significantly were the facts the two spacewalkers had to use a sharp, serrated knife to cut into the capsule's heat shield to gain access to the bolt... and once there, they had to be careful not to do anything to set the explosive charge off.

The Associated Press reports Volkov and Kononenko received somewhat mixed assurances from flight controllers in Moscow prior to their EVA. Controllers initially assured the cosmonauts the bolt would not explode, with the force equivalent to an M-80 firecracker. Their counterparts at NASA expressed similar confidence.

"We dream of a lot of wild things to do, and after much analysis, sometimes we do them and sometimes we don't," said NASA's station program manager Mike Suffredini this week. "We have quite a bit of confidence in this particular case that we're perfectly safe."

Nevertheless, as both spacewalkers started their work... controllers in Moscow adopted a more cautionary tone. "Take your time," Mission Control warned. "Be careful; be careful, please."

In addition to mixed messages from control, the spacewalk started on an ominous note. Kononenko was unable to secure himself to a foot restraint on the Strela hand-powered crane mounted nearby, so he tethered himself to the crane and held on. Volkov then maneuvered him to the Soyuz, docked to the Earth-facing port on the Russian Pirs module.

Upon reaching the Soyuz, Kononenko first used the knife to cut away the ablative material around the bolt, then both spacewalkers installed devices to channel static electricity away from the explosive. Once that was accomplished, Volkov was able to unscrew the explosive bolt, and stow it in a cylindrical, blast-proof case.

"It is in," one of the spacewalkers said.

"Good. Thank God," a controller replied in Russian, according to the AP. The cosmonauts then secured a heat-resistant covering around the area where the bolt was removed, and returned to the airlock.

Meanwhile, NASA astronaut Gregory Chamitoff wiled away the time inside the Soyuz capsule, in a precautionary move. NASA noted in the unlikely event the Pirs airlock couldn't be repressurized after the spacewalk, Chamitoff would not have had access to the capsule. So, while the two cosmonauts worked outside, Chamitoff kept himself occupied with books, music and a laptop computer... all the while listening to the repair efforts.

Both NASA and Roskosmos believe removal of the bolt will solve earlier re-entry problems with the Soyuz. As ANN reported, the service module failed to fully detach from the capsule carrying US astronaut Peggy Whitson, Russian cosmonaut Yuri Malenchenko and South Korean 'tourinaut' Yi So-yeon in April.

That failure resulted in a steeper-than-planned "ballistic" re-entry attitude, and the capsule's hard landing hundreds of miles off course. All three spacefarers survived the harsh conditions, though Yi was hospitalized days after the accident for neck and back pain. It was the second time in as many re-entries a problem developed with a Soyuz capsule's return to Earth, and the third since 2003.

The Soyuz has been the workhorse of Russia's space program since the late-1960s, and today is but one of two means (the space shuttle is the second) of carrying crew and cargo to the ISS. When the shuttle fleet retires in 2010, it will be the only way.

FMI: www.nasa.gov, www.roscosmos.ru/index.asp?Lang=ENG