August 21, 2007, 18:30
Astronauts aboard space shuttle Endeavour fired their ship's steering rockets to leave orbit today for an hour-long glide to Florida to wrap up a 13-day construction mission to the International Space Station.
Touchdown at the Kennedy Space Center's 4.8km, canal-lined landing strip was expected at 12:32pm. Flying upside-down and backward 344km above the Indian Ocean, Endeavour commander Scott Kelly and pilot Charles Hobaugh fired the shuttle's two maneuvering engines at 11:25am to begin the descent to Earth.
Endeavour and its seven-member crew has been in space for 13 days to deliver new components to the International Space Station and prepare the $100 billion complex for new laboratory modules.
"Although it's been a short two weeks, we've accomplished a lot and we still look forward to coming home today," Kelly told Mission Control in Houston, which played a few minutes of Simon and Garfunkel's song Homeward Bound as a wake-up call for the astronauts.
The crew includes Barbara Morgan, a former teacher who originally trained as the backup to Christa McAuliffe, a teacher who died in the ill-fated Challenger mission in 1986.
Endeavour hits hurdle
NASA ended Endeavour's planned 10-day stay at the station a day early when it appeared Hurricane Dean might prompt an evacuation of the Houston control centre. But the storm, which reached Mexico's Caribbean coast earlier today, headed farther south.
While mission managers lauded the crew's success in installing the station's new structural beam, replacing a failed steering gyroscope and configuring equipment to pave the way for future additions, the flight put NASA on notice that its $1.5 billion effort to recover from the 2003 Columbia disaster was not finished.
A small piece of insulation fell off Endeavour's tank at launch and smashed into two heat-resistant tiles on the ship's belly, sparking a six-day effort to determine if a risky spacewalk to plug the gash would be needed.
In the end, NASA managers said they were 100% confident the damage would pose no threat to the shuttle. But additional modifications on fuel tanks for the next three flights are under consideration, shuttle program manager Wayne Hale said.
Safety modifications
Fuel tanks earmarked for flights beyond the next three missions already have been changed to prevent foam loss from the area that shed insulation during Endeavour's climb to orbit on August 8.
NASA made modifications to the fuel tank after the loss of Columbia and its seven astronauts.
A suitcase-sized chunk of foam fell off Columbia's tank and hit the ship's wing, damaging the heat shield. As the shuttle flew through the atmosphere, superheated gases ate into the breach and tore the ship apart. - Reuters
|
|
