CAPE CANAVERAL, Florida (Reuters) - Space shuttle Atlantis prepared on Thursday to leave orbit after a successful mission that repaired the Hubble Space Telescope, but poor weather over Florida may delay Friday’s planned homecoming.
Shuttle Commander Scott Altman and his flight crew tested Atlantis’ rocket thrusters and other equipment needed to return through the atmosphere and land.
Touchdown is scheduled for 10 a.m. EDT (1400 GMT) on Friday at the Kennedy Space Center, with a back-up opportunity at 11:39 a.m. (1539 GMT)
The weather, however, may pose a problem. Powerful thunderstorms and heavy rain pummeled central Florida late on Wednesday, leaving cloudy skies and drizzle on Thursday that is expected to linger for several days.
Nevertheless, NASA told the astronauts to be ready to leave orbit in case the weather breaks.
“You know how the weather changes rapidly in Florida,” astronaut Greg Johnson told the crew from Mission Control in Houston. “We’ll plan as it comes.”
The shuttle has enough supplies to remain in orbit until Monday.
NASA said the shuttle is in good condition for landing following several inflight inspections of its heat shield by the crew. Heat shield damage is blamed for the 2003 Columbia disaster.
Atlantis is returning from NASA’s fifth and final servicing call to the 19-year-old Hubble telescope, which has been instrumental in expanding scientists’ understanding of the universe and widening public knowledge of astronomy.
Hubble’s unprecedented photographs of celestial objects include pictures of planetary nebula, which are colorful gas shells of exploded stars, and of a dizzying array of galaxies.
NASA is retiring the shuttle fleet next year and no other planned or existing spaceships have the capability of satellite servicing.
Working in teams of two, the Atlantis astronauts completed five occasionally grueling spacewalks to install new cameras, repair broken instruments and replace Hubble’s batteries and positioning gyroscopes.
The telescope also received fresh layers of thermal insulation and a docking ring so that a future spacecraft can hook up and steer the 13-ton observatory out of orbit toward its eventual final resting place in the ocean.
Without the servicing mission, Hubble’s effective operating days had looked short, with two of its main science instruments shut down by power failures and no gyroscopes to spare.
The spinning devices are needed to lock the telescope’s gaze on targets with the accuracy of a laser illuminating a coin several hundred miles (km) away.
The Atlantis crew’s refurbishments should keep the observatory on the cutting edge of scientific research until at least 2014 when its replacement, the infrared-sensitive James Webb Space Telescope, is scheduled to be in orbit.
“We all feel pretty good about what’s been accomplished,” Atlantis flight engineer Megan McArthur said during the crew’s inflight news conference on Wednesday. “But we’re also looking forward to taking a little bit of a break.”
Editing by Pascal Fletcher and Eric Beech