NASA announces Endeavour is good to go

William Atkins
Friday, 17 August 2007 19:18

Science - Space

NASA officials decided Thursday August 16, 2007, that the gouge on the underbelly of the space shuttle Endeavour would not be repaired and it is safe for commander Kelly to fly it home.

After several days of engineering analyses, the Mission Management Team at the Mission Control Center, Johnson Space Center, Houston, Texas, met for about five hours to make its final decision. Over thirty various NASA organizations took part in the decision.

In a nutshell, mission managers stated that all of the data indicated that the shuttle crew would not be in danger and that Endeavour would not suffer any serious structural problems if left as is during its extremely hot re-entry back into the Earth’s atmosphere next week. The decision was not unanimous, but was voted for by all organizations except for an engineering group at the Johnson Space Center.

Among the tests and modeling performed were computational fluid dynamics tests performed independently at the NASA Ames Research Center, Moffett Field, California, and the NASA Langley Research Center, Hampton, Virginia. In addition, a thermal analysis test was performed, along with two arc jet tests to show how the underbelly heats up during re-entry.

NASA estimates that the section of the Endeavour, which houses the gouge, reaches temperatures of 1,500 degrees Fahrenheit (815 degrees Celsius) during its descent into the atmosphere. Other TPS areas reach hotter temperatures, up to 3,000 degrees Fahrenheit (1,649 degrees Celsius).

Endeavour and its seven-member STS-118 crew are scheduled to return to the Earth on Wednesday, August 22 at about 12:52 pm EDT on the runway of the Kennedy Space Center, Florida.

The thermal shielding (part of the Thermal Protection System [TPS]) on the underside of Endeavour was hit by a piece of foam or ice debris, which broke off of the external tank, during liftoff of the shuttle. The small piece of debris left a 3.5 inch long, 2 inch wide, and 1.1 inch deep hole in the thermal tiles. The puncture also exposed about a 1 inch strip of the felt fabric that is laid beneath the tiles.

John Shannon, chairperson of the MMT, reported, "I am 100 percent comfortable that the work that has been done has accurately characterized it (the damage) and that we will have a very successful re-entry."