The combined crews of the space shuttle Endeavour and the International Space Station are taking a well-deserved day off today, after 10 days of hard work finishing up the Japanese Kibo laboratory module and getting the station ready for the day when shuttles are no longer visiting.
"We've gotten to do a ton of work up here, gotten to look out the window a little bit," said Endeavour pilot Doug Hurley in an interview this morning with Memphis television station WREG-TV. "We're hoping today to look out a little bit more, which is something that's, for a pilot, is pretty hard to describe, since I'm not very good with words. But it's incredible to look out the window."
Since arriving on orbit July 15 Endeavour's crew has inspected the orbiter's delicate thermal protection system to ensure it wasn't damaged during ascent; flown to rendezvous and docked with the station and swapped NASA's Tim Kopra for Koichi Wakata on the ISS crew roster. Together the 13 space travelers on board - representing all five of the ISS partner agencies -- have used a combination of spacewalks and complex choreography with all three robotic arms on the two spacecraft to install and outfit the exposed facility on Kibo where experiments can be conducted in open space. And they have delivered three big spare parts and replaced the oldest set of batteries on the station to keep it going after the shuttle stops flying next year.
"The space station we built is truly a modern miracle," said Dave Wolf, whose first spaceflight was a long-duration stay on Russia's old Mir orbital station. "... This is a meeting place of international cultures."
Wolf is lead spacewalker on this mission, and has completed his three scheduled extravehicular activities (EVAs). First-time space travelers Chris Cassidy and Tom Marshburn already have completed two each, and are scheduled for one more EVA on Monday. Cassidy apparently overwhelmed his spacesuit's carbon-dioxide scrubber on his first trip outside, forcing an early halt to the first of two EVAs scheduled to replace the batteries at the far port end of the main station truss.
Spacesuit experts at Johnson Space Center counseled the former Navy SEAL to start a little more slowly on his second outing, and he and Marshburn were able to finish the battery changeout on Friday. Cassidy told reporters today that while he never felt any ill effects from rising carbon dioxide levels in his suit on Wednesday, he learned that "slow and steady wins the race."
While the crew rests today, EVA planners in Houston will be scheduling the final spacewalk for Cassidy and Marshburn. Holly Ridings, the lead ISS flight director for this mission, says the top priority will be to rewire the power source for two of the big control moment gyros that help maintain the station's attitude in space so a single-point failure can't take both of them out. Other tasks on the to-do list includes reworking some of the insulation on Canada's Special Purpose Dexterous Manipulator, the big robot known as Dextre; installing a couple of cameras on the Kibo module, and setting up a stowage platform for more big spare parts that are scheduled to be delivered in the fall.
On Sunday the crews will use the shuttle and station robotic arms to remove an experiment carrier pallet from the Kibo "porch" and restow it in Endeavour's payload bay, hold a joint news conference, and start getting ready for Monday's spacewalk.
But for the rest of the day, they'll be enjoying the view from orbit, where the whole Earth passes below every 90 minutes.