A series of delays kept the mission from getting started until more than two years after its original flight date.
"This crew actually had the opportunity to spend a lot of time together," astronaut Scott Horowitz (search) said. "They were probably one of the closest-knit crews I have ever encountered. They were really upbeat every time you talked to them. They were a pretty happy group of folks."
The resulting bond has helped many of the crew families deal with the tragedy that cut short the lives and careers of their loved ones.
"They had worked hard. They had trained hard," said Audrey McCool, mother of astronaut William McCool. "For them all, it was the adventure of a lifetime."
Here is a look at the crew that flew on Columbia's final mission, the families they left behind and how they have coped:
———Commander Rick Husband, 45, was an Air Force colonel and former test pilot from Amarillo, Texas. He knew as a child he wanted to be an astronaut.
During the past year, his wife, Evelyn, wrote a book about him called, "High Calling." She says faith has helped her and her 13-year-old daughter and 8-year-old son through their grief.
"There are a lot of memories that I am reliving, especially this month, of all the lasts of what we did," she said. "The last time Rick was at home. The last time he hugged our kids. The last time we were together as a family. The last time we prayed together."
———Pilot William McCool, 41, was a Navy commander who grew up in Lubbock, Texas. As a teenager 25 years ago, he won a race in Brownfield, Texas, in which one of his competitors was George W. Bush.
Two weeks into his first space trip, McCool was bursting with amazement during the Columbia mission, calling his experience "beyond imagination" in a Jan. 30 interview with National Public Radio.
McCool was survived by his wife, Lanni, and three sons, then 14, 19 and 22.
"He would be so modest he wouldn't think that he deserved any legacy, but I suppose if he did, being able to encourage children to learn would be a real legacy for him," Audrey McCool said of her son.
———Payload commander Michael Anderson, 43, grew up on military bases. He was flying for the Air Force when NASA chose him in 1994 as one of only a handful of black astronauts. He traveled to Russia's Mir space station in 1998.
The lieutenant colonel, who called Spokane, Wash. home, was in charge of Columbia's dozens of science experiments.
Anderson was married and had two daughters, who are now 10 and 12. He enjoyed chess, tennis and photography.
"He was just a kind man and I miss that. I miss talking to him. I miss all of those things that a wife would miss about her husband," Sandy Anderson said of her husband. "Right now we have just been trying to keep our family together and heal and mend."
———Mission specialist David Brown, 46, was a Navy captain, pilot and doctor, who grew up in Arlington County, Va. He joined the Navy after a medical internship, then went on to fly the A-6E Intruder and F-18. He became an astronaut in 1996. Columbia's mission was his first spaceflight.
When asked in an interview about the risk of flying in space, Brown, who was single, said he had made a decision when he joined the Navy as a pilot that everyday risk would be a part of his job.
"The decision to go fly in space," he said, "is just an extension of that."
His brother, Doug Brown, said, "Dave would want to be remembered for pursuing his dream to go to Mars. In knowing that a Mars mission would most likely come after the end of his career he was in constant search of the next great challenge."
———Mission specialist Kalpana Chawla, 41, emigrated to the United States from India in 1980s with the plan of designing aircraft.
As an astronaut, she was a heroine in India, which has launched satellites for years and is preparing for a moon orbit this decade. One Indian news agency even tracked Columbia's flight so it could tell readers the exact minute they could wave to the skies to hail their countrywoman.
Her husband, pilot Jean-Pierre Harrison, said after she died that what attracted him to her was "her inner fire to do well." The risk she took in her job was something they both accepted, he said.
———Mission specialist Laurel Clark, 41, who grew up in Racine, Wis., was a diving medical officer aboard submarines and then a flight surgeon before she became an astronaut.
Her doctor-husband, Jon, continues to work for the space agency as a flight surgeon and to raise the couple's 9-year-old son. Clark says he wants more transparency into the tragedy.
"You've got to be out in the open about it," he said. "You've got to say, 'How did this thing come apart? How did the crew die?' "
Clark said his wife would want to be remembered as a source of inspiration and also for change at NASA.
———Payload specialist Ilan Ramon, 48, was the first Israeli in space. A fighter pilot in two Israeli wars, his mother and grandmother survived the Auschwitz death camp.
He carried with him into space a copy of a small drawing titled "Moon Landscape" by Peter Ginz, a 14-year-old boy who died at Auschwitz.
Married, he left a daughter and three sons, ages 5-15.
His wife, Rona, has declined most interview requests, but she was among astronauts' families who last year visited a number of schools and science centers worldwide.
"It's tough to go out and talk to people because we know they (astronauts) were supposed to be here and not us," she said, "but we need to keep their legacy alive and feel it is our mission to do this."