CAPE CANAVERAL, Fla. (AP) – With good weather forecast for launch time, NASA fueled space shuttle Endeavour in preparation for a Wednesday evening liftoff and the climax of a two-decade wait for teacher-turned-astronaut Barbara Morgan.

In 1986, Ms. Morgan was Christa McAuliffe’s backup for the Challenger flight, the shuttle mission that was meant to send NASA’s first teacher into space.

Ms. Morgan was watching a few miles from the launch pad when the Challenger exploded barely a minute into flight.

Many of the other educators who had competed with McAuliffe and Ms. Morgan to become the first teacher in space were in Florida on Wednesday to watch Endeavour finally take one of their own into orbit.

Ms. Morgan, 55, will be seated on the lower deck in the middle, the same spot where McAuliffe sat 21 years ago.

“I think the great thing about it is that people will be thinking about Challenger and thinking about all the hard work lots of folks over many years have done to continue their mission,” Ms. Morgan said last month.

Wednesday morning, NASA had nearly completed pumping more than 500,000 gallons of supercold liquid hydrogen and liquid oxygen into the ship’s tank.

Forecasters gave NASA an 80 percent likelihood that the weather would be favorable for the scheduled 6:36 p.m. liftoff.

Among those on hand for the launch, the widow of Challenger’s commander called Ms. Morgan a role model for students because of her patience and perseverance in following her dream.

“The Challenger crew – my husband Dick Scobee, the teacher Christa McAuliffe – they would be so happy with Barbara Morgan. They’d be excited for her, they’d be proud of her and her following through with the mission for the teacher to fly in space,” said June Scobee Rodgers, founding chairman of the Challenger Center for Space Science Education.

The seven-member crew is slated to spend two weeks at the international space station on a mission to continue construction of the orbiting outpost. They will attach a new truss segment to the space station, replace a gyroscope that helps control the station’s orientation, and deliver 5,000 pounds of cargo.

If the mission is extended from 11 days to 14 days, a decision that won’t be made until the mission is well under way, the astronauts could add a fourth spacewalk to install protective panels to protect the station from debris.

Endeavour was initially scheduled to lift off Tuesday but was delayed for a day because NASA had to replace a leaky valve in the crew cabin.

The astronauts assigned to the mission included a Canadian doctor, a chemist who knows sign language and is a former competitive sprinter and long jumper, and a commander whose identical twin brother is also a shuttle pilot.

Ms. Morgan, who in 1998 became the first teacher to join the astronaut corps – trained to conduct tasks on a mission, rather than to fly as a guest as McAuliffe had planned – is scheduled to operate Endeavour’s robot arm and oversee the transfer of cargo from the shuttle into the station.
First lady Laura Bush called her Tuesday to congratulate her. While in space, Morgan also plans to answer questions from schoolchildren.

___

On the Net:

NASA: http://spaceflight.nasa.gov