CAPE CANAVERAL -- NASA's efforts to put the International Space Station program back on track took a major step forward yesterday with the safe return of the shuttle Discovery after a near-flawless 13-day mission.
Astronauts accomplished every objective during their visit to the $100 billion space station, including the deliveries of a new resident and 3 tons of equipment and supplies. The flight's larger significance, however, might be that it positions the space agency to begin a final push of 15 more missions needed to finish the station before the planned retirement of the shuttles in 2010.
"This is as good a mission as we've ever flown, but we're not going to get overconfident," said NASA Administrator Michael Griffin. "We've got 16 flights to go to assemble the space station and, hopefully, do a Hubble [Space Telescope] repair. ... But we've got to take that one flight at a time."
NASA's shuttle and space station programs had been struggling for three years to regain momentum since the loss of Columbia in February 2003. After the shuttle disaster, the space station was placed in a caretaker status while NASA engineers struggled to stop foam insulation from breaking off the external fuel tank during liftoff - the cause of the Columbia accident.
Launch photography and inspections during Discovery's flight indicate no major foam loss or damage to the orbiter's heat shield. The performance of the redesigned tank appeared to validate the decision of shuttle managers who went ahead with the July 4 launch despite "no go" votes from NASA's head of safety and chief engineer.
Three dozen small foam ramps on the tank that were the primary source of concern won't be changed for at least three flights. However, it appears the ramps shed little if any foam during Discovery's launch.
"This is my fourth flight, and I've done four walk-arounds," shuttle commander Steve Lindsey said after inspecting Discovery's heat shield yesterday. "I've never seen a vehicle that has looked as clean as this one."
Discovery's six shuttle astronauts delivered needed equipment and supplies. Spacewalkers Piers Sellers and Mike Fossum repaired a mobile platform needed to move the station's robot arm between work sites. The repair was considered critical for future assembly flights.
The shuttle also dropped off German astronaut Thomas Reiter, who will live at the station for about six months. It marks the first time since 2003 that the station will be staffed by three people, enabling a greater focus on research.
"I can't think of a better mission in recent history," said Mike Suffredini, NASA's space station program manager. "Every objective we went in with was completed."
Discovery's safe return paves the way for the launch of Atlantis in six weeks on a mission that will add power-producing solar arrays to the station.
Mission managers are confident that Atlantis will be ready for its first flight since October 2002. The challenge will be turning around Discovery fast enough to support a rescue flight if something goes wrong.
"We are launching in just about six weeks from today on probably the most complicated assembly mission that's ever been scheduled in human spaceflight," said Wayne Hale, NASA's shuttle program manager.
Michael Cabbage and Robyn Shelton write for the Orlando Sentinel.