The Discovery astronauts found sunny skies in California on Friday as they descended to a weather-delayed landing at Edwards Air Force Base to end a demanding two-week mission to the International Space Station.
Earlier in the day, thunderstorms twice prevented the seven astronauts from landing at NASA’s Kennedy Space Center, a replay of the foul conditions on Thursday that kept the shuttle orbiting for an extra day.
Discovery discharged a pair of sonic booms as it soared across the California coast at the end of a high speed descent over the Pacific Ocean and touched down at the air base north of Los Angeles at 7:53 pm (0253 GMT Saturday).
“Welcome home, Discovery,” Mission Control radioed shuttle commander C.J. “Rick” Sturckow. “Congratulations on an extremely successful mission.”
Discovery will be hoisted atop a Boeing 747 jumbo jet and flown back to Kennedy late next week as a result of the stormy Florida weather, said Mike Moses, who chairs NASA’s mission management team. The cost of the cross country trip is about 1.8 million dollars.
Discovery dropped off more than 18,000 pounds (8.1 tons) of supplies, life support gear and scientific equipment at the space station, leaving the space outpost better equipped to house crews of six astronauts as NASA prepares to retire its aging space shuttle fleet by early 2011.
A half-dozen shuttle missions remain, each intended to gradually bring the assembly of the 15-nation space station to an end.
“We’re pretty fat on supplies now, thanks to you,” space station resident Mike Barratt told the shuttle astronauts as they departed earlier this week. “We’re in better shape to carry out our work.”
Fellow American Tim Kopra, who ended a 58-day mission to the space station, was among those aboard Discovery.
“This experience has completely exceeded anything I thought it would it would be like, just in sights and sounds, the experiences,” said Kopra. “It’s been absolutely phenomenal.”
He was replaced on the station by Discovery astronaut Nicole Stott. She joins five Russian, European and Canadian astronauts. She will return aboard shuttle Atlantis, which is tentatively scheduled to launch on November 9 with a load of major external spare parts for the orbital base.
A first time space voyager, Stott has trained to capture Japan’s new HTV cargo capsule with the station’s robot arm as the unmanned supply ship coasts within 30 feet of the station.
The HTV was launched from the Tanegashima Space Center in southern Japan on Thursday.
The Japanese supply craft, loaded with food, science experiments and other hardware, is expected to reach the station on September 17.
“That will be exciting for us,” Stott said this week. “The vehicle flies up, and we go to work with the big robot arm to pick it out of space — grab it! — bring it in and dock it to the station.”
The HTV is expected to lay a vital roll in the station’s future. As NASA retires the shuttle, it plans to turn to a pair of American commercial rocket companies to haul supplies to the orbital outpost. Both will rely on the same robot arm berthing technique that Japan’s HTV will initiate.
Discovery delivered a pair of major new science experiments that will enable the astronauts to study the behavior of metals, glasses and ceramics as they are heated and cooled in the absence of gravity.
A third new experiment enclosure, a refrigerator, will store blood and other medical specimens collected from the astronauts for studies on how they adapt physically to weightlessness.
During three spacewalks, Discovery’s crew upgraded an external cooling system. Spacewalkers also collected samples of materials that could be included in the fabrication of future spacecraft including a replacement for the shuttle.
The samples were left outside the station a year ago to determine how they would react to the space vacuum, the sun’s ultraviolet radiation and a reactive form of oxygen in the Earth’s upper atmosphere.
During the final outing, astronauts stretched power and data cables to prepare the outpost for one of its last habitable modules. The American furnished “Tranquility” module is scheduled for launching in early 2010.
Inside the outpost, the astronauts installed a new bedroom, replaced a failed piece of life support equipment that removes carbon dioxide from the breathing air and delivered an exercise treadmill named for Stephen Colbert, an American late night television host and satirist.