Astronauts seal hatches for shuttle's departure

By Irene Klotz

CAPE CANAVERAL, Florida (Reuters) - Shuttle Discovery's astronauts bid a tearful farewell to the International Space Station crew, returned to their spaceship and sealed the hatch on Sunday after a successful, though trying, 10-day mission.

Pilot George Zamka is scheduled to fire Discovery's steering rockets at 5:32 a.m. EST on Monday to disconnect from the orbital outpost. The shuttle is scheduled to land at the Kennedy Space Center in Florida at 1:02 p.m. EST on Wednesday.

The hatch's closure was delayed by about an hour as the astronauts scrambled to load last-minute items from the station that need to be returned to Earth. The crews then gathered for a hasty and emotionally charged farewell ceremony.

"We simply could not have accomplished the mission without everybody's help," said Discovery's teary-eyed commander Pamela Melroy. "The two crews have worked together so well. We're family now."

Stowing all the gear for the trip home and making a final inspection of their ship's heat shield are about all that is left on the shuttle crew's long to-do list.

The astronauts accomplished their primary jobs -- installing a new module with docking ports for partners' laboratories and relocating one of the station's three main sets of solar power panels -- and tackled a major and unexpected repair task as well.

When one of the station's power wings was re-extended in its new location, wires snagged, causing the delicate panel to rip. NASA refocused the rest of the flight on trying to recover the wing, which needed to be fully extended to provide structural rigidity.

If the crew had not been able to repair the wing, construction of the station would have been put on hold.

To reach the two tears, Discovery's lead spacewalker, Scott Parazynski, attached himself to an extension boom borrowed from the shuttle that was mounted on the station's 50-foot-(15 meter-)long robotic crane. Taking care not to let the electrically charged power panel touch him, Parazynski installed five homemade braces to buttress broken hinges in the ship's wing.

The spacewalk, the fourth during Discovery's mission, was hastily pieced together by engineers and technicians who worked around-the-clock to choreograph the unprecedented repair work.

"What we accomplished yesterday was just incredible," flight director Rick LaBrode told reporters on Sunday. "That's got to be the major high" of the mission.

NASA is running out of time for completing assembly of the station, a $100 billion project of 16 member nations. Eleven construction missions remain before the shuttle fleet is to be retired in 2010. NASA also would like to squeeze in two station resupply flights and a final servicing call to the Hubble Space Telescope.

The shuttle crew includes returning space station flight engineer Cliff Anderson, who was replaced by astronaut Dan Tani.

Tani joins station commander Peggy Whitson and Russian flight engineer Yuri Malenchenko, who arrived at the outpost three weeks ago. They will not have much time for relaxing.

As soon as the shuttle pulls out of its berthing port on Monday, the station crew will begin reconfiguring the outpost for the arrival of Europe's Columbus laboratory, which is targeted for launch aboard shuttle Atlantis between December 6 and 13.