CAPE CANAVERAL, Fla. (AP) _ The countdown clock on Sunday began ticking toward a Wednesday launch of the space shuttle after a week of weather delays kept Atlantis grounded.
The launch time was set for 12:29 p.m. EDT Wednesday. If the shuttle does not lift off then, NASA has launch opportunities on the following two days.
Engineers and technicians at the Kennedy Space Center planned to spend the coming days checking out flight software, testing navigational systems and fueling the cells that will power Atlantis' systems.
This is the second time a countdown was started for this mission of Atlantis, which originally was to blast off Aug. 27. The launch was delayed after lightning struck the launch pad, requiring engineers to check for damage to Atlantis' systems.
Then Tropical Storm Ernesto blew through Florida.
With the storm approaching, NASA managers on Tuesday ordered the shuttle returned indoors to the vehicle assembly building. Midway through the four-mile journey, managers reversed themselves and decided once Ernesto's intensity was downgraded to return the shuttle to the launch pad. The reversal gave NASA an opportunity to launch this week, rather than several weeks later.
Atlantis will deliver a 35,000-pound, $372 million addition to the half-built international space station during the 11-day mission. Four astronauts will take three spacewalks to resume construction on the orbiting space lab, which stopped being built 3 1/2 years ago after the space shuttle Columbia disintegrated while returning to Earth.