(CNSNews.com) - A senior government official says NASA's data shows a "major systems failure," CBS News reported Saturday afternoon.
Videotape showed a large piece of something coming off the orbiter immediately prior to its mid-air breakup over Texas Saturday morning. NASA reportedly is focusing on the space shuttle Columbia's left wing as the possible source of the catastrophic failure.
NASA said there is no indication that the breakup was caused by anything or anyone on the ground.
However, press reports noted that during the launch of the space shuttle Columbia 16 days ago, a piece of insulation came loose and appeared to hit the left wing of the shuttle. It's not clear what the extent of the damage may have been, if there was any damage at all.
Temperature stress on the shuttle is highest during the re-entry period. It was on re-entry that Mission Control lost communications with Columbia.
Space shuttles are protected from the heat of re-entry by an intricate system of heat tiles, according to Robert G. Melton, a professor of aerospace engineering at Pennsylvania State University.
According to Melton's research, "shuttle orbiters use a system of 30,000 tiles made of a silica compound that does not ablate, but does rapidly radiate heat away from the orbiter. These tiles can be repaired in space."
Melton's research notes that the "major disadvantages are fragility," among the heat tiles, which are "easily damaged before launch and by orbital debris; lots of tile damage due to debris since anti-satellite tests in mid-80s.
Another shortcoming of the tiles, according to Melton's research, is their complexity and the fact that "many people (are) needed to manually attach tiles to orbiter in a tedious and time-consuming process, and to inspect them all before launch."
Melton's research indicates that during the re-entry period, maximum temperatures are recorded at an altitude of 40 miles with a speed of 15,000 miles per hour.
It is also during this time that communications are routinely disrupted because of ionization, which is caused by the high temperatures and "creates an impenetrable barrier to radio signals," according to Melton's research.
According to NASA, contact with Columbia was lost when the shuttle was flying at roughly 200,000 feet at a speed of more than 12,000 miles per hour.