CAPE CANAVERAL, Fla. —  When former schoolteacher Barbara Morgan leaves Earth on a space shuttle next week, she hopes her students back in Idaho learn a lesson from her 22-year wait to get into orbit: perseverance and patience.

That's what defines teachers, said the astronaut, who is achieving her dream at age 55.

Morgan will fly with six other astronauts to the international space station on the shuttle Endeavour, assuming launch goes forward on Tuesday as planned.

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The mission comes less than two weeks after am embarrassing report by a panel of medical experts suggested some astronauts were cleared to fly after drinking too much — despite concerns raised by flight surgeons and other astronauts. NASA says it's investigating those claims.

The report on astronaut health also called for regular psychological tests.

Endeavour commander Scott Kelly said he has already discussed behavior expectations for the upcoming flight. Until the news about possible astronaut drinking, most of the attention in recent weeks has been on the next mission and Barbara Morgan.

In 1985, Morgan was chosen from thousands of applicants to be the back-up to teacher-in-space Christa McAuliffe.

They trained together at Johnson Space Center in Houston for six months, and it was McAuliffe who was on board Challenger when it blew apart on Jan. 28, 1986.

A poorly designed seal in the shuttle's solid rocket booster was blamed for the disaster that killed her and six astronauts.

After the Challenger accident, Morgan returned to teaching grade school students in Idaho, but NASA asked her to stay on as the teacher-in-space designee.

She gave speeches and served on a federal task force for women. She helped NASA figure out how to include space in schools' curriculum.

She waited to go to space.

NASA struggled with whether to continue the teacher-in-space program or whether to include teachers in the astronaut experience in another way. The agency chose the latter, and in 1998 Morgan was asked to become a full-fledged astronaut. Three other teachers have since joined the astronaut corps.

For Morgan, astronaut-educators are just another category of professionals in the astronaut corps. NASA's original astronauts were test pilots, but the astronaut corps opened up to scientists and engineers during the Apollo program in the late 1960s.

Morgan's duties during the Endeavour mission will include helping move 5,000 pounds of cargo from the shuttle to the space station and relocating a stowage platform using the shuttle's robotic arm.

"She's a tough cookie and I don't think anything is going to stand in the way of her doing the job that she has been asked to do and that she has been trained well to do," said crew mate Tracy Caldwell, who was selected in the same astronaut class as Morgan.

Unlike McAuliffe, who wasn't a fully trained astronaut, Morgan has no plans to give a lesson from space. Instead she will answer questions from schoolchildren in Idaho. If the 11-day shuttle mission is extended to 14 days as expected, she also will get a chance to talk to young students in Virginia and Massachusetts.

"Because she is an educator, we will be able to get the attention of students and educators in a way which perhaps we were unable to do in previous missions," said Joyce Winterton, NASA's assistant administrator for education.

The Endeavour crew — which includes commander Scott Kelly, pilot Charles Hobaugh and mission specialists Tracy Caldwell, Dave Williams, Rick Mastracchio and Alvin Drew — have been good- natured about all the attention on Morgan, although Kelly recently admitted it has been a little distracting.

"If you have any other questions for the rest of the crew, Barbara will be happy to answer them," Kelly joked to reporters.

The astronauts will be flying in a vehicle that has been refurbished from nosecap to tail, part of a regular maintenance overhaul for the shuttles every three or four years.

During the 11-day mission, the astronauts will deliver 5,000 pounds of cargo to the space station, attach a new truss segment to the outpost and replace a gyroscope which helps control the station's orientation. Three spacewalks are planned.

If the mission is extended to 14 days_ a decision that won't be made until the mission is well under way — the astronauts will take a fourth spacewalk to install protective panels to stop debris from hitting the station.

Despite her celebrity, Morgan has insisted all along that McAuliffe "was, is and always will be our first teacher in space" — even though McAuliffe technically never reached space since Challenger broke apart 73 seconds after liftoff.

"I'm just another teacher going in space and there are more to come," Morgan said. "People will be thinking of Christa and the Challenger crew and what they were trying to do and that's a good thing."