Astronauts' Final Spacewalk Cut Short

Last Updated 12:43 p.m. ET.

Astronauts Thomas Marshburn and Christopher Cassidy wrapped up a 4-hour 54-minute spacewalk today, the fifth and final excursion planned for the shuttle Endeavour's space station assembly mission.

The spacewalkers installed two Japanese television cameras on a new experiment platform, fixed an insulation problem on a Canadian robot and re-wired a gyro control circuit.

But with less carbon dioxide absorbent available in Cassidy's suit than expected, CBS News space analyst Bill Harwood reports, flight controllers told them to forego deploying a payload attachment mechanism. That task will be carried out by station astronauts or a future shuttle crew.

For today's spacewalk, the astronauts were using a rechargeable chemical known as METOX to scrub carbon dioxide from their air supplies.

"Consumables, METOX for Tom is seven (hours) plus zero zero, METOX for Chris is five plus three zero. Those are non-conservative numbers," astronaut Aki Hoshide radioed from mission control. "When we did the math on the ground, with the 15 minutes out for cleanup, we're past the bingo time for the PAS deploy. Just wondering what you guys think."

"We'll declare bingo. Simple," David Wolf replied from the shuttle-station complex.

CBS News correspondent Peter King reports the astroanuts had already completed installation of insulation on Canada's Special Purpose Dexterous Manipulator, a robotic "hand" designed for the space station's robotic arm, and rewired gyroscopes on the space station.

Instead, the spacewalkers carried out a few minor activities before returning to the space station's Quest airlock.

"Great job, outstanding EVA," Japanese astronaut Aki Hoshide radioed from Houston after Marshburn and Cassidy floated back into the Quest airlock module. "We're all very happy to work with you, it's a privilege. Thanks and congratulations on five EVAs."

Hoshide congratulated the astronauts for completing work on the JEF assembly, an exposed experiment platform for the Japanese Kibo laboratory. The TV cameras the astronauts installed are needed for the upcoming docking of a Japanese cargo craft in September and for normal experiment work on the JEF.

"Well, that is a big deal," Wolf replied. "You guys have a fabulous space agency and it's an amazing laboratory, both internal and at vacuum. It's been a privilege to work with you to complete it."

"I can verify from up close, it is indeed a beautiful laboratory," Marshburn agreed.

"Perhaps among the best (in) space," Wolf concluded.

"Thank you, guys, for getting the porch out," Hoshide said of the exposed facility. "On behalf of JAXA (the Japanese space agency) and the Japanese community, I'd like to thank you guys."

Cassidy and Marshburn will also make their way to the Japanese Exposed Facility, a porch-like experiment platform attached to the Kibo laboratory module earlier in the mission to install two television cameras.

This was the 130th spacewalk devoted to station assembly and maintenance since construction began in 1998, the 11th so far this year and the fifth for Endeavour's crew. Going into today's EVA, total station spacewalk time stood at 805 hours and 42 minutes, or 33.6 days. Endeavour's total through four spacewalks was 25 hours and 36 minutes.

Shuttle Endeavour will undock from the International Space Station on Tuesday. The mission created the largest gathering ever in space, with 13 people.

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