On the morning of their second day in orbit, a fragment of the left wing drifted away from the spacecraft.
No one noticed.
For eight days, different groups of debris analysts lobbied shuttle managers for permission to inspect Columbia's wings using Defense Department satellites.
Although the space agency prided itself on outspoken openness, the organization was actually run from the top down. Shuttle managers blocked or ignored the requests.
Worried engineers could not bring themselves to break the chain of command. In an agony of indecision, they pushed only so far and no further.
Had they detected the wing damage in time, agency engineers might have improvised a repair in orbit or a rescue mission. Either would have been a long shot.
All the crew heard about the arguments over the debris came in an e-mail message from flight director Steve Stitch eight days into the mission.
Concerned that reporters might ask the astronauts about the foam at a news conference, Stitch told them the foam striking the wing was otherwise "not even worth mentioning."
"We have seen this same phenomenon on several other flights, and there is absolutely no concern for entry," Stitch told them.
"Thanks a million, Steve," shuttle commander Husband replied in an e-mail on Jan. 25. "And thanks for the great work on your part."
Within the shuttle's white eggshell of thermal tiles, the crew members were exhilarated.
During a lull in the routine, Kalpana Chawla floated gently over the flight deck.
She watched the sun set.
In the overhead windows, she could see her reflection along with the day and night sides of Earth.
"I called all the crew members one by one and they saw it," she said during a news conference on Jan. 29. "Everybody said, 'Oh, wow!' "
Three days later, it was time for them to come home.