NASA announces revised shuttle mission schedule

Barbara Morgan, who was the backup for Christa McAuliffe on the doomed 1986 Challenger flight,is scheduled to become the first teacher in space on Aug. 9,NASA announced Monday.

Canadian astronaut Dave Williamswill also be aboard space shuttle Endeavouron themission slated for launchon Aug. 9. The mission will mark Williams' second trip into space.

The announcement came as officials at the U.S. National Aeronautics and Space Administration's Johnson Space Center laid out six missions through April 2008, saying they had yet to assess flight dates beyond a year.

Flights have been postponed since the external fuel tank of the space shuttle Atlantiswas damaged in a February hail storm, putting its launch on hold. The Atlantis now will be launched no earlier than June 8, NASA officials said, verifying an announcement made April 10.

The Aug. 9launch of Endeavorwill mark the first space shuttle flight of an "educator astronaut,"mission specialist Morgan, who is part of NASA's new program to enable teachers to go to space.

Morgan was the backup candidate to McAuliffe, also ateacher,in what was then NASA's Teacher in Space program. McAuliffe was killed with the rest of the space shuttle Challenger's crew when the vehicle exploded shortly after launch on Jan. 28, 1986.

After the Challenger disaster, Morgan was namedTeacher in Space designee and spent several months speaking to educational groups throughout the U.S. She returned to teaching in fall 1986 but continued to work with NASA's education division, and was selected to be the first educator astronaut in 1998.

Morgan was scheduled to go into space on the space shuttle Columbia in November 2003, but her first flight was put on hold with the whole program when Columbia broke apart over Texas in February 2003.

The August launchwill also also mark the second trip to space for Canadian astronaut Williams, who is expected to take three spacewalks during the mission to the International Space Station.

Four other space shuttle flights are scheduled in the next year.

Discovery will be used instead of Atlantis in a scheduled Oct. 20 flight, and on April 24, 2008, the final flight of the series announced Monday.

Atlantis will be used instead of Discovery for the scheduled Dec. 6 launch.

Endeavour is to be used for a mission scheduled to take off on Valentine's Day, Feb. 14, 2008.

The mission swaps between Atlantis and Discovery are meant to minimize disruption to the flight schedule and best meet mission requirements, NASA officials said.