Realtime coverage of STS-134 EVA No. 4

CBS News/Kennedy Space Center

08:10 AM EDT, 05/27/11 Update: STS-134 EVA No. 4 ends

Astronauts Michael Fincke and Gregory Chamitoff attached the shuttle Endeavour's heat shield inspection boom to the International Space Station Friday, completing the U.S. segment of the orbital lab complex after 12 years of construction and more than 1,000 hours of spacewalk assembly time.

Astronauts Michael Fincke and Gregory Chamitoff make their way back to the Quest airlock after wrapping up the final space station assembly EVA by a shuttle crew. (Credit: NASA)
Pausing to snap a final few pictures before returning to the Quest airlock, Chamitoff marked the milestone with a brief tribute to Endeavour, the shuttle and station programs and the thousands of engineers and technicians around the world who contributed to the high-flying project.

The shuttle Endeavour's heat shield inspection boom is maneuvered into position for attachment to the space station by the lab's robot arm. (Credit: NASA)
"At this time, now that we're almost done here, I wanted to say a few words," he said. "This is the last flight of the space shuttle Endeavour and it's also the last spacewalk of shuttle crew members in station assembly. It's kind of fitting that Endeavour is here because Endeavour was the first shuttle∫ to begin construction of the station and so it's fitting that she's here for the last mission to finish assembly.

"During this EVA, we tallied altogether collectively over a thousand hours of spacewalks as part of station assembly. Mike and I have the honor here to share this last spacewalk and of course, with all the folks working on the ground, the thousands of people who helped build this, working in the shuttle and the station programs. We're floating here on the shoulders of giants. This space station is a pinnacle of human achievement and international cooperation -- 12 years of building and 15 countries. And now it's the brightest star in the sky and hopefully the doorstep to our future. So congratulations everybody on assembly complete."

The Russians plan to add at least one more module to the station, a laboratory called Nauka that will take the place of the Pirs docking compartment in 2011 or 2012. Thirteen Russian spacewalks are planned to decommission and undock Pirs and to attach the new multi-purpose lab module.

Chamitoff and FIncke began repressurizing the station's Quest airlock compartment at 7:39 a.m. EDT (GMT-4) to officially conclude a seven-hour-hour 24-minute spacewalk, the 159th EVA devoted to station assembly and maintenance since construction began in 1998, the eighth so far this year and the fourth and final excursion planned by Endeavour's crew. Total space station EVA time now stands at 1,002 hours and 37 minutes, or 41.8 days.

It was the ninth spacewalk for Fincke, who now ranks as the sixth most experience spacewalker in the world with 48 hours and 37 minutes of EVA time, and the second for Chamitoff, whose total stands at 13 hours and 43 minutes. The total for Endeavour's mission through four EVAs is 28 hours and 44 minutes.

The primary goal of the final shuttle spacewalk was to attach Endeavour's no-longer-needed heat shield inspection boom to the space station and to attach a grapple fixture that will permit the lab's robot arm to use it as a 50-foot-long extension for future maintenance and repairs. The astronauts also released clamps on a spare robot arm fitting.

"I wanted to say congratulations to the shuttle program for all the wonderful successes we've had over the past 30-something years," Fincke said in the airlock. "It's a privilege that Endeavour's hosting the last spacewalk by a space shuttle crew. So congratulations to the EVA development teams. We've come a long way. From me and Greg and the rest of the crew, congratulations."

The shuttle Atlantis is scheduled for launch July 8 on the 135th and final shuttle mission to deliver critical supplies to the outpost. One spacewalk is planned, to retrieve a failed coolant system pump and to install an experiment, but it will be carried out by space station crew members.

12:40 AM EDT, 05/27/11 Update: STS-134 EVA No. 4 begins

Floating in the International Space Station's Quest airlock, astronauts Michael Fincke and Gregory Chamitoff switched their spacesuits to battery power at 12:15 a.m. EDT (GMT-4) to officially kick off a planned six-and-a-half-hour spacewalk, the fourth and final excursion planned for the shuttle Endeavour's mission.

The first major objective of today's EVA is to mount the shuttle's no-longer-needed heat shield inspection boom on the space station's solar power truss, giving the lab's robot arm a 50-foot-long extension for use during future maintenance and repair work.

This is the 159th spacewalk devoted to station assembly and maintenance since construction began in 1998, the eighth so far this year, the fourth and final EVA planned by the Endeavour astronauts, the ninth for Fincke and the second for Chamitoff.