Adapting to weightlessness was hard. Readapting to gravity was even tougher for teacher-astronaut Barbara Morgan.
Morgan passed up the opportunity to check out space shuttle Endeavour with her six crewmates after Tuesday's landing.
She was too weak and wobbly and hinted that she was nauseated, as well.
"Actually, I was doing some good science back there," she later said with a laugh, referring to how she remained in the crew transport vehicle following touchdown.
"The room still spins a little bit, but that's OK," she said.
Morgan — who was Christa McAuliffe's backup for the doomed Challenger flight in 1986 — said it took her a while to adjust to space. "I felt like I was upside down that entire first day," she said.
She's hoping the readjustment to Earth's gravity won't take as long. At a news conference six hours after touchdown, she still looked pale and shaky, but was able to walk unassisted.
"Probably easier adapting to weightlessness than now, but don't get me wrong, this isn't that bad," she told reporters. "It will go away and it's actually pretty interesting if you could be in my body."
As for her 13-day flight, it was "absolutely wonderful." Morgan said she can't wait to see what schoolchildren and teachers do with the 10 million basil seeds she carried into space. The plan is for students to devise mini-greenhouses like the two she left behind at the international space station.
When asked about her future plans, Morgan said with a smile, "My first plan is to get rid of the room spinning, and that should happen pretty soon."
She said she really wants to figure out how the space agency can do a better job helping students and teachers. "And I would love to figure out how we can make more and more of these opportunities available for more of our teachers."
Morgan, 55, was teaching elementary schoolchildren in McCall, Idaho, when she was chosen as McAuliffe's backup. After the launch disaster, she returned to teaching. NASA invited her into the astronaut corps in 1998, and she began training as a full-fledged mission specialist.
Slideshow 12 photos
Month in Space: January 2014
The 2003 Columbia disaster delayed her mission from fall of that year until now.
Morgan said she wishes she could have devoted more time to education in orbit but knew time would be limited because of the station construction mission.
As it turns out, the flight was shortened by a day because of concerns about Hurricane Dean, and Morgan lost out on an opportunity to speak with children in Lynn, Mass.
She managed to answer questions from youngsters in Boise, Idaho, and Alexandria, Va., earlier in the mission, and squeezed in a session with Canadian students at flight's end.
"I feel grateful that we got the time that we got; I really, really do," she said.