They said they were confident, however, that the suspect piece of foam was so small that it could have caused no damage that would prevent Discovery from returning safely to Earth.
A space agency graphic showed the trajectory of one small piece arcing toward the right wing and then abruptly changing course. NASA officials said they were concerned by the prospect that debris may have hit the wing, since that was found to be the cause of the Columbia disaster more than two years ago.
NASA Wednesday halted all future scheduled shuttle flights with the announcement that a large piece of foam, measuring 30 inches by up to 14 inches, had come off the external fuel tank, saying the flights were grounded until engineers can figure out what is causing the foam to fall off. Managers said yesterday at a news briefing in Houston that they didn't know how long the shuttle fleet would be grounded.
In anticipation of a delay of months or more, they are making preparations to transfer even more water and other cargo to the International Space Station than planned. Hale said the agency was considering extending the orbiter's stay at the space station, and therefore the mission, by a day to accomplish the transfers. One job they may perform is to repair a balky treadmill on the station and bring back extra parts.
Despite the new concerns, NASA managers felt better enough about the safety of the orbiter and of the seven-person crew that they focused on what Hale called "a great day in space today for us. We had a wonderful docking, very smooth and graceful."
Discovery docked with the space station at 7:18 a.m., as the station orbited over the South Pacific, 220 miles above Chile. Crew members shook hands and hugged the station crew, Commander Sergei Krikalev and flight engineer John Phillips.
Krikalev gave the visitors bread and salt, a traditional good luck offering to travelers in Russia. The Russian symbolism, translated into English, means, "With bread I will not starve and with salt I will not die," NASA said.
Before docking, Discovery Commander Eileen Collins performed a first-ever back flip maneuver that allowed Krikalev and Phillips to snap photos of the underside of the orbiter, where a portion of a heat-resistant tile chipped off during launch.
The space station crew got 93 seconds worth of images. "Neither of us saw anything alarming," Phillips said.
"Initial reports are everything looks extremely good and we don't have anything to worry about" with the tile, flight operations director John Shannon said at a media briefing hours later.
The Los Angeles Times is a Tribune Publishing newspaper.