NASA on Monday forecast a 70 percent chance of good weather for Wednesday's space shuttle launch, an event the US space agency hopes will help the public forget the recent stories of drunk and lovesick astronauts.
The National Aeronautics and Space Agency started the countdown for the Endeavour shuttle Sunday at Cape Canaveral, Florida, at 8:00 pm (2400 GMT) Sunday toward liftoff scheduled for 6:36 pm (2236 GMT) on August 8.
Jeff Spaulding, NASA Test Director, said there were no outstanding problems that might stall the flight.
"At this point, we are on schedule and are tracking no significant issues," he told reporters Monday.
Cape Canaveral meteorologist Kathy Winters forecast the likelihood of good weather for Wednesday's launch window.
"Currently, there's only a 30 percent chance that isolated showers or anvil clouds could prevent launch," she said, adding that the same forecast extended to Thursday in case of a 24-hour launch delay.
NASA hopes the second shuttle flight this year will help cure a media hangover from reports of astronauts drinking on the job and the sabotage of a computer by a NASA contractor employee.
Both revelations last month -- and the case earlier this year of astronaut Lisa Nowak allegedly trying to kidnap a rival who was dating another married astronaut -- dealt a blow to the professional, disciplined image the high-profile US space agency tries to maintain.
The crew includes 55 year-old school teacher Barbara Morgan, a career elementary school teacher who first trained for a space flight two decades ago. She will carry on for Christa McAuliffe, who died when Challenger shuttle exploded shortly after lift-off in 1986, cutting short her bid to become the first teacher in space.
The team of seven astronauts, including mission commander Scott Kelly and co-pilot Charlie Hobaugh, arrived Friday at the Kennedy Space Center in Florida from the Johnson Space Center in Houston, Texas.
The mission will transport a truss section about the size of a small car, weighing 1.58 tonnes, to extend the space station to a length of 108 meters (354 feet).
The astronauts will also replace a defective gyroscope, one of four keeping the space station on an even keel, and will install a 3.3 tonne exterior stowage platform.
Endeavour, on the 22nd shuttle mission to the space station, will also carry in its cargo bay a pressurized container with 2.7 tonnes of supplies, foodstuffs and equipment.
Three spacewalks, lasting about six hours and 30 minutes each, will allow the two-astronaut teams to accomplish assembly and repair tasks during the 11-day mission.
However, NASA could prolong the mission by three days to include a fourth space walk, to prepare for installation of a boom that will allow crews to inspect the heat shields of future shuttles for damage while docked with the space station.
NASA has been leery of damage to shuttle heat shields since February 2003, when a broken thermal tile on the Columbia shuttle allowed superheated gases to enter its wing on re-entry, causing the shuttle to break up and killing its crew of seven.
The disaster put the shuttle program on hold for two-and-a-half years.
