On the first full day of a remarkably smooth flight, the space shuttle Atlantis' crew checked out their ship's protective skin in near-record time Saturday.
The astronauts conducted a detailed survey of Atlantis' tiles in just under five hours — about an hour and a half less than the job was expected. That meant they could get some extra rest and relaxation at the end of their day. That was in keeping with the theme so far for NASA's last-ever space shuttle flight.
"The performance of this particular crew on this set of activities is probably near record-breaking," said Kwatsi Alibaruho, the lead flight director for Atlantis' resupply mission to the International Space Station.
The post-launch inspection was added to the routine for every shuttle mission after the 2003 Columbia tragedy, when an undetected breach in the leading edge of Columbia's left wing led to the catastophic breakup of the orbiter and the loss of its seven-member crew.
Atlantis' crew is limited to four astronauts as an indirect consequence of that accident. If the shuttle had been so seriously damaged during ascent that it couldn't make an atmospheric re-entry, the astronauts would have to be rescued by a series of Russian Soyuz craft. Usually, a rescue shuttle would be standing by for launch — but because Atlantis is the last shuttle standing, there are no spares.
Critical areas of the shuttle were scanned by a camera and sensors mounted on the end of a 50-foot-long (15-meter-long) inspection boom, which in turn was mounted on the shuttle's robotic arm.
While the astronauts were at work, they got words of praise from Mission Control. "It's really a pleasure watching you guys work today," spaceflight communicator Steve Robinson told the crew.
LeRoy Cain, head of NASA's mission management team, said he and his colleagues were focusing on "finishing strong."
"We wanted the last flight to be the safest flight that we fly. We wanted the performance of the vehicle to be the best it's ever been," Cain said. "I think you're seeing it play out."
The small size of the crew may be a factor behind the smoothness of the flight, Alibaruho said. Conditions are less cramped, the air quality is better and the temperature tends to be more comfortable. Also, all four of the astronauts are veterans, and thus were less likely to suffer from space sickness — a feeling of nausea and dizziness that afflicts many spacefliers in the first days of a mission.
Alibaruho cautioned, however, that Atlantis' last mission had just begun. "This is Flight Day 2," he said. "We've got plenty more opportunities to fall behind and experience problems, but we'll do our best to avoid that."
Initial indications were that no significant damage was done to the shuttle during Friday's ascent. Over the next few days, experts on the ground will be closely checking the inspection imagery as well as high-resolution pictures that are to be taken just before Atlantis' docking with the International Space Station on Sunday.
The top objectives of Atlantis' mission are to transfer tons of supplies for the space station, drop off a contraption that will be used to test techniques for refueling satellites in space, and bring back a broken coolant pump module from the space station.
Mission managers say they are close to being able to extend the shuttle flight from 12 days to 13 days, needing to find just one more hour of on-orbit power to put off landing until July 21. That is usually accomplished by conserving energy on board.
Alibaruho said he expected a decision on extending the mission to come by Monday. "I think we will probably get there,' he said.
Atlantis' landing will end 30 years of space shuttle flights. After the Columbia accident, NASA and the White House decided to retire the fleet and shift funds over to the development of new spaceships for going beyond Earth orbit.
Contractors are already working on the capsule for such missions, known as the Orion multipurpose crew vehicle, and an announcement on NASA's next-generation, heavy-lift rocket is expected within weeks.
After Atlantis, Soyuz spacecraft will be used to transfer astronauts to and from the space station, at an estimated cost of $50 million a seat. Russian, European and Japanese robotic transports will carry cargo. Eventually, U.S-made commercial vehicles — developed with NASA support — will be used for NASA's cargo as well as station-bound crew.
Every step of Atlantis' mission is imbued with the sense that this is a farewell tour for the shuttle: On Saturday, the morning's wake-up song — Coldplay's "Viva la Vida" — was accompanied by a mass greeting from employees at NASA's Marshall Space Flight Center in Alabama, which focuses on the shuttle's propulsion system.
"We wish you a successful mission and a safe return home," the workers said in their pre-recorded message.
Atlantis pilot Doug Hurley responded, "Thanks for that great message and awesome ride to orbit and the 134 before that with this tremendous space shuttle program."
This report includes information from The Associated Press.