Ten years ago, a crowd of several hundred people gathered at NASA's Kennedy Space Centre in Florida for the anticipated landing of space shuttle Columbia and its crew of seven following 16 days in space. The craft and its occupants never arrived.
"All of a sudden we realised things were not as they were supposed to be," recalls Wayne Hale, retired shuttle program manager. "We were in a state of shock, quite frankly."
NASA remembers Columbia
NASA remembers the crew of the Columbia Space Shuttle on the 10th anniversary of the accident.
Family members of the crew of five men and two women were hustled into vans and whisked to private quarters, where they were given the tragic news as scientists, engineers and managers of NASA pored through data chronicling the catastrophic end of Columbia and its mission, code-named STS-107.
NASA is marking the anniversary with low-key ceremonies in Florida and Texas honouring the crew of Columbia as well as those who died in the January 28, 1986, Challenger shuttle explosion and earlier lost astronauts.
Among those participating are some of the crew family members who were at Kennedy on February 1, 2003. Lost were Commander Rick Husband, co-pilot William McCool, specialists Kalpana Chawla, Laurel Clark, Michael Anderson, David Brown, and Ilan Ramon, an Israeli fighter pilot.
The shuttle broke apart as it re-entered the atmosphere and streaked across the US's skies. Parts of the shattered spacecraft rained down across a broad expanse, much of it centred over Hemphill, Texas.
Days later, Milt Heflin, then chief flight director and now associate director of the Johnson Space Centre, walked into a hangar at Barksdale Air Force Base in Louisiana. Bright xenon lights illuminated the "busted, twisted, scorched hardware". It was, he recalls, "a morgue of high-speed technology".
The disaster was attributed to a piece of foam that fell from the external rocket tank on launch, opening a hole in a shuttle wing that caused the craft to rip apart on re-entry.
The accident investigation spread blame broadly, citing management and organisational deficiencies. Among them: a culture that didn't like to hear safety concerns from lower-level engineers.
"In the 10 years since the Columbia investigation, the accident report has become a landmark study in organisational causes of accidents," Hale says. "That's the enduring legacy. We learned ... cultural and management lessons."
The shuttle fleet was grounded and although missions resumed in 2005, President George W. Bush decided to wind down the shuttle program. The last shuttle flew in 2011, and the remaining shuttles have become museum pieces.