Awwal 25, 1432 H/Feb 28, 2011, SPA -- A pair of visiting shuttle astronauts ventured out on a spacewalk at the International Space Station on Monday, tackling a hodgepodge of maintenance jobs and an experiment to capture the invisible vacuum of space, according to AP. The spacewalk was interrupted at the two-hour mark when a robotic work station shut down in the orbiting lab. The astronauts operating the robot arm _ with spacewalker Stephen Bowen perched on its end _ rushed to another computer station in another room. It took a while to get the second station working. For nearly a half-hour, the station arm was motionless, with Bowen stuck gripping a big, broken pump that needed to be moved. He dared not let go. Mission Control asked if he was comfortable. «I'm fine as long as it's not too much longer?» Bowen radioed. «How much longer?» Close, he was told. But it took several more minutes until the robot arm could come back to life. Finally, the operation resumed and Bowen carried the 780-pound (353-kilogram), 5-feet (2.74-meters)-by-4-feet pump over to its new location on the exterior of the space station. He got help from spacewalking partner Alvin Drew in latching the pump down. Bowen, the lead spacewalker, was a last-minute addition to Discovery's last crew. He is filling in for an astronaut who hurt himself in a bicycle crash last month. Mission Control couldn't resist a little Academy Awards humor at the expense of injured astronaut Timothy Kopra, who monitored the action from a flight controller's seat. In a morning message to the Discovery crew, Mission Control sent up a cartoon showing a spacewalking astronaut _ Bowen _ holding an Oscar statue and giving an acceptance speech. «... and I would like to thank all of the little people that made this EVA (extravehicular activity) happen,» the cartoon spacewalker said. «And a special shout out to Timmy Kopra. Get well little buddy!» There won't be another chance for Kopra, at least during a shuttle flight. This is Discovery's final voyage, and only two other shuttle trips remain. The fleet will be retired by summer's end. This was the first of two spacewalks planned for Discovery's farewell flight. The biggest job involved the relocation of the failed ammonia coolant pump. It was replaced last summer in a series of urgent spacewalks. Back then, the space station residents ran out of time before they could secure the broken device in its proper place. NASA hopes to return the pump on one of the two remaining shuttle flights. Bowen and Drew also installed an extension power cable that paved the way for Tuesday's planned installation of a small storage room at the space station. The chamber arrived aboard Discovery over the weekend. In a lighthearted experiment saved for the end of the spacewalk, the astronauts were to open a small hand-held bottle, ridding it of air and filling it with the vacuum of space. NASA calls the Japanese education experiment «message in a bottle.» There's no message inside, but the bottle is signed by astronauts who have flown in space. It will be returned to Earth aboard Discovery next week and put on display in Japan. It's an effort by the Japanese Space Agency to increase public interest. In a bit of space trivia, Drew became the world's 200th spacewalker when he emerged from the 220-mile-high complex. The first was Soviet cosmonaut Alexi Leonov in 1965. «Alvin will now be able to say that he works in a vacuum,» Mission Control said. Bowen and Drew will go back out Wednesday for one last spacewalk. Once back home, Discovery will be retired and sent to the Smithsonian Institution. It's NASA's longest flying shuttle, circling the planet for nearly a year during the course of 39 missions over 26 years. Shuttle Endeavour, meanwhile, was moved into NASA's Vehicle Assembly Building down in Florida as the spacewalk unfolded. It should head to the pad next week for an April 19 launch.
