Live in orbit: Japan's space station lab complete

Assembly of Japan's Kibo science lab complex on the International Space Station is complete, but two spacewalkers won't get to the last major task planned today.

Endeavour spacewalkers Tom Marshburn and Chris Cassidy this morning finished installing two television cameras on the lab's exposed platform, called the porch, which was installed earlier in the mission.

That wrapped up assembly of the porch, which was the last of Kibo's three major elements. The lab's construction began 18 months ago and spanned three shuttle missions.

After a couple more clean-up tasks, congratulations were exchanged.

"Congratulations, you guys just completed the (Japanese Exposed Facility) assembly," said Aki Hoshide, a Japanese astronaut communicating with the crew from NASA's Mission Control Center in Houston.

"That is a big deal," said Endeavour mission specialist Dave Wolf, who is guiding the spacewalkers from inside the shuttle. "It's an amazing laboratory both internal and at vacuum that you have. "

"That is a huge deal," one of the spacewalkers said.

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

"Yes it is," said Cassidy.

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

Though the work appeared to be running ahead of schedule, flight directors determined that it would take too long for the spacewalkers to complete the last of the day's major tasks.

If time allowed, they hoped to install a mechanism that will hold large spare parts on the station's truss.

Instead, they are doing some "get-ahead" work on the porch, installing some handrails and foot restraint holders on the porch that will help future spacewalks.

As a result, today's spacewalk, which was expected to last about 6.5 hours, will probably end early.

It was not immediately clear why there was not enough time to install the Payload Attach System on the Starboard 3 truss segment.

Hoshide indicated that Cassidy might only be able to stay outside about 5.5 hours because of his spacesuit's ability to absorb carbon dioxide, which has been an issue in each of his spacewalks.