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.