NASA Administrator Sean O'Keefe says it's a "tragic day for the NASA family." O'Keefe spoke to reporters at Florida's Kennedy Space Center after space shuttle "Columbia" broke up into flames on its way to landing, killing all seven astronauts. He says there's no indication it was caused by anyone or anything on the ground.
O'Keefe says President Bush has spoken to the crew members' families to express the "deepest national regrets." His voice choking with emotion, O'Keefe said it started out as a "happy morning" at Kennedy Space Center. He says officials couldn't wait to congratulate what he calls a "valiant crew" and "a more courageous group of people you could not have hoped to know."
The NASA chief says the astronauts dedicated their lives to tackling scientific challenges for everyone on Earth, and that they did it with a "happy heart." He says NASA has appointed both an investigation team and an independent panel to find out what caused the tragedy.
Meanwhile, the U.S. military is providing some help in the search for shuttle debris. Fort Hood is located near the debris site in Texas, and officials say the Army's First Cavalry Division has sent a search force.
The search teams will use Blackhawk helicopters during the day and Kiowa Warrior helicopters at night. Also, military police will be used in the search and guarding of wreckage. NASA has warned the material is dangerous, and officials also want to collect all the material for its investigation.
In Houston, flags are waving at half-staff at NASA's Johnson Space Center, where the astronauts train, and businesses and public buildings in the area joined in.
The final radio communication between NASA and space shuttle "Columbia" sounded like a routine communication, but it's taken on a whole new meaning. The communication message was heard shortly before 9:00 a.m. Eastern time.
The communication starts with a mission controller at the Johnson Space Center in Houston saying, "Columbia, Houston we see your tire pressure messages and we did not copy your last." A reply comes from an astronaut believed to be shuttle commander Rick Husband, who says "Roger." The transmission then breaks off after the crew member starts to say a word starting with the sound "buh."
A NASA official says it's too early to speculate on what caused the tragedy. O'Keefe says it wasn't caused by anything or anyone on the ground. A senior U.S. official says there's no immediate sign of terrorism -- and no specific threats against Columbia had been made. The source also says the shuttle would've been out of range of a surface-to-air missile when it broke up.
During liftoff of Columbia a piece of insulating foam from the external fuel tank came off and struck the left wing. Lead Flight Director Leroy Cain told reporters at the time damage to the wing was considered minor and posed no safety hazard.
In 42 years of manned space flight NASA has never lost a crew during re-entry. In 1986 seven astronauts were killed when space shuttle Challenger exploded 80 seconds after blastoff. Columbia is the oldest of NASA's shuttle fleet, first launched in 1981. It was on its 28th mission.
The shuttle flight had seven crew members, including Ilan Ramon, an Israeli Air Force Colonel who is the first Israeli to fly in space. Because of his presence on board, increased security has surrounded the entire Columbia mission.