By Irene Klotz
CAPE CANAVERAL, Florida (Reuters) - NASA downsized the crew for the final flight of its shuttle program as a safety precaution.
Instead of the usual six- or seven-person crew, only four astronauts were aboard the Atlantis on its 13-day cargo run to the International Space Station. It was the first time in 28 years NASA had gone with a crew that small, choosing to do so because there was no shuttle available for a rescue flight if Atlantis was somehow damaged and could not make the trip home.
NASA would have had to rely on Russian Soyuz spacecraft, which fly with two pilots and one passenger per vehicle, to bring the astronauts back if needed.
Christopher Ferguson, 49, a soft-spoken retired Navy captain, was the commander of the Atlantis astronauts, who dubbed themselves "The Final Four."
He said he never expected to make the flight, which initially was just a standby rescue mission for the last shuttle crew.
"I'd given it a 50-50 shot at best," he said.
But last year, NASA decided to fly Atlantis with a year's worth of supplies for the station, an insurance policy of sorts in case the new companies hired to haul cargo to the outpost encounter delays.
Ferguson, a married father of three who grew up in Philadelphia, is a drummer in the astronauts' semi-professional band, MaxQ. Before joining NASA in 1998, the Top Gun pilot flew several types of aircraft for the Navy. This was his third spaceflight.
Assisting Ferguson with piloting Atlantis was Douglas Hurley, 44, a Marine Corps colonel who grew up in Apalachin, New York. He is married to astronaut Karen Nyberg and father of their 17-month-old son.
Hurley, who had made one previous shuttle mission, plans to remain an astronaut and is interested in a lengthy mission on the space station.
Atlantis' flight engineer Rex Walheim, 48, is a retired Air Force colonel who grew up in San Carlos, California. Married with two teenage sons, Walheim planned to take some mental snapshots during his third trip into space.
"Last time when the main engines started, it just felt like the whole thing was shaking to pieces. I could barely read the displays," he said. "This time, I want to feel the whole kick-in-the-pants."
The veteran spacewalker did not head outside the station during Atlantis' mission, although he supervised a spacewalk made by two space station astronauts.
Completing the Atlantis crew was Sandra Magnus, 46, of Belleville, Illinois, who had the unglamorous job of "load master." She was responsible for making sure the 5 tons of food, clothing and other supplies on the shuttle made it to the station, and all the old equipment and trash that need to come back to Earth were packed on the shuttle.
The flight, Magnus' third, was a bit of homecoming. She served as a member of the live-aboard station crew from November 2008 to March 2009.
Asked what her future holds, Magnus said earlier this month that she had not had time to think about it.
"It's like you've always wanted to be an astronaut your whole entire life and now you've done what you've always wanted to do," she said. "What do you do next?"
Atlantis was scheduled to land at 5:57 a.m. EDT (0957 GMT) on Thursday at the Kennedy Space Center in Florida.
(Writing by Irene Klotz; Editing by Jane Sutton and Bill Trott)