The astronauts aboard the linked space shuttle and space station began their high-priority girder work Wednesday, a two-day job that will culminate with the installation of two new solar wings at the orbiting outpost.
They cranked up the robot arm on the international space station and used it to latch onto the 45-foot (13.7-meter)-long, 31,000-pound (14,060-kilogram) frame structure that flew up aboard the shuttle Discovery. The framework, which holds the folded-up wings, was then hoisted out of the shuttle payload bay.
Discovery's robot arm assisted with the work.
The $300 million girder — which has a radiator along with the solar wings — is the last major American-made piece of the space station. And the pair of wings are the station's last.
In between chores, station skipper Mike Fincke, shuttle commander Lee Archambault and the two former schoolteachers on board, Joseph Acaba and Richard Arnold II, shared their space experiences with Channel One, a newscast for teenagers.
Arnold and Acaba, who are making the first double educator-astronaut flight, fielded the food and toilet questions. Arnold held up a bag of candy — "never go anywhere without a little bit of chocolate" — pulled a piece out and let it float. Acaba grabbed and ate it.
As for using the bathroom in orbit, Acaba said it's like camping but takes more effort, and stressed the importance of a good seal on the commode.
"The last thing we want to have is our commander seeing something floating around the cabin," Acaba said.
Fincke, who's just a few days shy of having spent an entire year in space on all his missions, answered the Great Wall of China question. You can't see it from space, he said, but the Great Pyramids of Egypt are visible with the naked eye because of the great contrast with the surrounding desert.
Meanwhile, the complicated and drawn-out task of hooking up the girder must wait until Thursday. Two spacewalkers will be outside, helping to attach the framework to the space station.
The 10 space travelers and flight controllers around the world will be watching anxiously when the new wings are commanded to open Friday. The last time new wings were delivered in 2007, one got snagged on a guide wire and ripped, and spacewalking astronauts had to carry out emergency repairs to fix it.
NASA officials said they have learned their lessons. The latest 115-foot (35-meter) wings will be commanded to open a small section at a time, and Mission Control will make sure there is optimal lighting when the procedure takes place. Sun glare contributed to the 2007 mishap; it prevented the astronauts from quickly noticing the wing had torn.
The wings carried up aboard Discovery are actually the oldest; they were used for testing on the ground. Because they have been packed up in boxes for as long as eight years, some of the pleated panels might stick together. The astronauts have techniques to work around that, if necessary.
Discovery will remain at the space station until next Wednesday. The shuttle arrived on Tuesday.
Late Wednesday, Mission Control told the shuttle commander that there will be no need for a more detailed inspection of the thermal shielding of his ship. Engineers had been studying a thermal tile on a wing flap that was damaged during liftoff, but concluded it was no threat for re-entry in one and a half weeks.