STS 123 FD\12

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OBSS Attached to Station, Fifth Spacewalk Continues

Image above: An astronaut exits the U.S. Quest airlock beginning the fifth spacewalk of the STS-123 mission. Credit: NASA TV

Mission Specialists Robert L. Behnken and Mike Foreman began the fifth spacewalk of STS-123 at 3:34 p.m. EDT. Rick Linnehan, also a mission specialist, is coordinating their activities from inside the orbiting complex made up of space shuttle Endeavour and the International Space Station.

Behnken and Foreman have successfully attached the Orbiter Boom Sensor System (OBSS) to the station’s S1 Truss. With the OBSS in the grip of the station’s robot arm earlier, the two spacewalkers assembled an umbilical designed to keep the boom safe while it is stored in the harsh space environment. Then, the robot arm handed the OBSS off to Behnken and Foreman to be placed on S1.

The next component of the Japan Aerospace Exploration Agency’s Kibo laboratory, which will be delivered on space shuttle Discovery during the STS-124 mission, is too large to accommodate the OBSS in the shuttle’s payload bay. Once the next element of Kibo is installed on the station, Discovery’s astronauts will detach the OBSS left behind by space shuttle Endeavour, use it to perform tile inspections and bring it home.

In addition, the spacewalkers are tasked with installing the Materials International Space Station Experiment 6 on the outside of the European Space Agency’s Columbus laboratory, an activity the astronauts were unable to complete during the mission’s third spacewalk. They also will perform other tasks including an inspection of the starboard Solar Alpha Rotary Joint.

With the final STS-123 spacewalk complete, flight day 14 will see the crew of Endeavour prepare for the end of their visit to the station. The orbiter will undock Monday and return to Earth Wednesday.