| Table of contents |
|
2 Effect on US space program 3 Investigation 4 Shuttle Crew of Flight STS-107 5 External Links |
At about 05:54 PST (08:54 EST), a California news photographer observed pieces breaking away from Columbia as it passed overhead, as well as a red flare coming from the shuttle itself.
At about 09:00 EST (14:00 UTC) on February 1, 2003, NASA's Mission Control at Lyndon B. Johnson Space Center in Houston, Texas lost radio contact with the space shuttle Columbia, at the end of mission STS-107, as it descended from orbit towards Cape Canaveral, near the John F. Kennedy Space Center and Jacksonville, Florida.
Contact was lost while the shuttle was flying at about 203,000 feet (38 miles or 62,000 metres) above north central Texas, at over 12,500 miles per hour (20,000 kilometres per hour = 6 km/s = Mach 18). At time of the communications disruption Mission Control was discussing abnormal sensor readings with Columbia. Columbia began their last message with the words "Roger, uh, buh..." but nothing more was transmitted. Telemetry and tracking data appeared to be lost at the same time. The shuttle was expected to land at 09:16 EST.
At about 9:05, residents of north central Texas reported a loud boom, a small concussion wave and smoke trails and debris in the clear skies above the counties southeast of Dallas. More than 2,000 debris fields, as well as human remains, were found in sparsely populated areas southeast of Dallas from Nacogdoches in East Texas, where a lot of debris fell, to western Louisiana and the southwestern counties of Arkansas. NASA issued warnings to the public that any debris could contain hazardous chemicals, that it should be left untouched, its location reported to local emergency services, or government authorities and that anyone in unauthorized possession of debris would be prosecuted.
Shortly after being told of reports of pieces of the shuttle being seen to break away, the NASA flight director declared a contingency (events leading to loss of the vehicle) and alerted search and rescue teams in the area, telling all controllers to "lock the doors" or preserve all the mission data for later investigation.
At 14:04 EST, a somber President Bush addressed the nation: "This day has brought terrible news and great sadness to our country... The Columbia is lost; there are no survivors." Despite the major setback, the President reassured Americans that the space program would continue: "The cause in which they died will continue... Our journey into space will go on."
The space shuttle program was suspended. The expansion of International Space Station was also delayed, as the space shuttles were the delivery vehicle for station modules. The station was supplied and crews exchanged using Russian manned Soyuz spacecraft and unmanned Progress ships. Russia's space shuttle program was shut down in 1993.
NASA's Space Shuttle Program Manager, Ron Dittemore, reported that "The first indication was loss of temperature sensors and hydraulic systems on the left wing. They were followed seconds and minutes later by several other problems, including loss of tire pressure indications on the left main gear and then indications of excessive structural heating."
Analysis of 31 seconds of telemetry data which had initially been filtered out because of data corruption within it showed the shuttle fighting to maintain its orientation, eventually using maximum thrust from its reaction control system jets.
Upon procedural review the day after lift-off of video taken during lift-off, it was observed that a piece of insulation foam falling from an external fuel tank had appeared to strike the shuttle's left wing. After some deliberation, it was concluded that the "event did not present a safety concern". The initial post-accident view remained that it could not have been the cause.
STS-107 had been delayed for 6 months (the original launch date was 19 July 2002) because of cracks in the propellant feed lines to the 3 main engines - a defect that could have caused catastrophic failure. There were suggestions of a connection between this and the disaster.
With the addition of the first Israeli astronaut to the crew, security surrounding the launch and landing of the space shuttle had been increased to avoid any potential terrorist attack. The Cape Canaveral launch facility, like all sensitive government areas, had increased security measures put in place in the wake of the September 11 attack. Because of the high altitude of the shuttle when the incident occurred, it was thought highly unlikely that terrorist actions were involved. Gordon Johndroe, spokesman for the United States Department of Homeland Security, stated: "There is no information at this time that this was a terrorist incident."
Following protocols established after the loss of Challenger an independent investigating board was created immediately following the accident. The Columbia Accident Investigation Board, or CAIB, consisted of expert military and civilian analysts who investigated the accident in great detail.
Columbia's data recorder was found near Hemphill, Texas on March 20, 2003. Because Columbia was more of a test vehicle than the other orbiters, the data recorder contained very extensive logs of structural and other data which allowed the CAIB to reconstruct many of the events during the process leading to breakup, often using the loss of signals from sensors on the wing to track how the damage progressed. This was correlated with analysis of debris and tests to obtain a final conclusion about the probable events.
NASA officials released experimental findings on May 30 proving that the insulation known to have hit the leading edge of Columbia's left wing could have created a gap in between protective heat panels. The findings showed that a joint, known as a T-seal, shifted after being hit with foam insulation traveling at the same speed the actual foam was traveling when it hit the left wing. The gap was small, 0.6 cm x 55 cm, but some researchers not on the investigation team have stated that a gap of that size was sufficiently large enough to act as a catalyst for further widening during re-entry. On June 24, the investigators have more confidently stated the flyaway foam to be "the most probable cause" of the wing damage.
On August 26, 2003, the CAIB issued its report on the accident. The board report confirmed the immediate cause of the accident as a breach in the leading edge of the left wing, caused by insulating foam shed during launch. The report also delved deeply into the underlying organizational and cultural issues that led to the accident. The report was highly critical of NASA's decision-making and risk-assessment processes, to the point of concluding that whoever was in the key decision-making positions, the systems and roles were arranged so that safety compromise could be expected. This included the position of Shuttle Program Manager, a role in which one individual was responsible for achieving safety, timely launches and acceptable costs, each a goal conflicting with the others. It found that NASA had institutionally accepted unacceptable deviations from design criteria as normal when they happened on several flights and did not lead to fatal consequences. One of those was the conflict between a design specification saying that the heat shielding system did not need to withstand impact damage and the common occurrence of impact damage to it during flight. It made recommendations for significant changes in processes and culture
In late July 2003, an Associated Press poll revealed that Americans' support for the space program remained strong, despite the tragedy. Two-thirds believed the space shuttle should continue to fly and nearly three-quarters said that the space program was a good investment. On the question of sending humans to Mars, 49 percent thought it was a good idea, while 42 percent opposed it. Support slipped for sending civilians like teachers into space with 56 percent supporting the idea and 38 percent opposed.
On August 6, 2003 NASA announced [1] that seven asteroids discovered in July 2001 at the Mount Palomar observatory were named in honor of the seven astronauts: 51823 Rickhusband, 51824 Mikeanderson, 51825 Davidbrown, 51826 Kalpanachawla, 51827 Laurelclark, 51828 Ilanramon, 51829 Williemccool.
See also: List of space disasters
Timeline
Effect on US space program
Investigation
The Columbia Accident Investigation Board
Shuttle Crew of Flight STS-107
On March 26 the United States House of Representatives' Science Committee approved funds for the construction of a memorial at Arlington National Cemetery for the STS-107 crew. A similar memorial was built at the cemetery for the last crew of Space Shuttle Challenger.External Links