Spacewalkers Remove Explosive Bolt from Russian Craft
|
|
Russian Cosmonauts Sergei Volkov, wearing the red-striped spacesuit, and Oleg Kononenko, wearing the blue-striped spacesuit, ventured outside the International Space Station July 10, 2008. They began their spacewalk at 2:48 p.m. EDT. CREDIT: NASA TV |
Cosmonauts successfully removed an explosive bolt from a Russian Soyuz spacecraft during a Thursday spacewalk.
Space station commander Sergei Volkov and flight engineer Oleg Kononenko dealt calmly with the unusual operation outside the International Space Station (ISS) as first-time spacewalkers, despite early troubles setting up a Strela hand-powered crane to reach the work site.
The removal of the explosive bolt represents part of a continuing Russian investigation into what caused the two previous Soyuz missions to go off-course and undergo ballistic reentries during their return to Earth.
Ten of the pyro bolts typically fire to separate the Soyuz instrument module from the return module. That allows the Soyuz to point its heat shield downward to protect itself from the heat of reentry.
However, a mysteriously delayed separation of the modules forced the latest three-person Soyuz crew to endure a steep ballistic reentry and gravitational forces reaching up to 10 times those on Earth. South Korea's first spaceflight participant, So-yeon Yi, detailed the experience as ?scary? and was briefly hospitalized afterward for neck and back pain.
Russian engineers want to check the pyro bolts for signs of environmental damage from electromagnetic or plasma forces around the space station and Soyuz spacecraft. NASA officials are also interested in the results of the investigation, because the Soyuz will provide the only access to the space station for a time after the space shuttle retires.
Trouble and improvisation
The two cosmonauts opened the hatch of the Pirs airlock on the ISS at 2:48 p.m., officially beginning a roughly six-hour spacewalk.
Delays mounted at the start of the spacewalk, as the cosmonauts struggled to set up the Strela crane meant to carry Kononenko to the work site.
?Strange, I had it,? Kononenko said while struggling to get his feet planted in the crane?s foot restraint. Russian mission control finally told the cosmonaut to tether himself to the crane.
The cosmonauts kept their humor, and even remembered their third space station crewmate. U.S. astronaut Greg Chamitoff sat inside the Soyuz during the entire spacewalk, so that he would be able to escape from it in the unlikely case of an emergency in which the airlock used for the spacewalk could not be re-pressurized.
?We can probably go ahead and scare Greg a little through the window,? one cosmonaut said.
Kononenko reached the Soyuz first on the crane and did not spot any ?expensive or criminal? damage to the spacecraft. He and Volkov then took photos and placed covers on the Soyuz thrusters to prepare for their main operation. Kononenko then used a serrated knife to cut away insulation from the Soyuz spacecraft work site.
?We feel sorry for the vehicle.? Kononenko said in a stab at humor.
?We?re not damaging it, we?re healing it,? fellow spacewalker Volkov replied, but maintained a serious tone as he warned his crewmate to be careful with the knife.
The spacewalkers applied a set of pliers called ?dino cutters? to ground static electricity in the area, and used other tools and even sheer force to remove an electrical locking ring, electrical connector and wire tie that held the pyro bolt in place.
Russian mission controllers asked Volkov to take Kononenko?s place at one point, and repeatedly requested the cosmonauts to rest and not tire themselves.
A successful return
The crowning moment of the spacewalk arrived as Volkov used a socket wrench to unscrew the explosive pyro bolt from its housing. Kononenko stood by with the blast-proof case to secure the bolt, which has the power roughly equivalent to a large M-80 rocket.
Russian mission controllers asked the cosmonauts to count the number of turns with the socket wrench. An estimated 10 turns was needed to remove the bolt.
?After five, please be very careful,? said a Russian mission controller.
The cosmonauts paused at eight turns as they conferred their plan of action, and then cooperated to loosen the bolt and put it into its secure case.
?Good! Thank God, it is in,? exclaimed one cosmonaut. The main objective was completed at 3 hours and 58 minutes into the spacewalk.
Russian mission control dictated a five minute break ?without any motions, without moving,? before allowing the cosmonauts to complete the spacewalk by placing a protective thermal blanket over the area where insulation was cut away.
Mission controllers also decided to delay the secondary goal of the mission to install a docking target on the Zvezda service module. That is instead planned to occur during the second spacewalk scheduled for July 15, when the cosmonauts are slated to outfit the Russian segment exterior as well as install and remove science experiments.
MORE FROM SPACE.com
Image Albums
Countdowns
Topics
Infographics
