Posted on 06/11/2003 6:29:09 PM PDT by foreverfree
Next Shuttle Launches to Be Daylight-Only
By PAUL RECER, AP Science Writer
WASHINGTON - The space shuttle in the future will only be launched in daylight, under the scrutiny of powerful cameras, and astronauts may be trained for spacewalking inspections if engineers suspect the heat shield was damaged during the launch, NASA (news - web sites) administrator Sean O'Keefe said Wednesday.
Despite extensive analysis of the space shuttle program and hardware following the Columbia accident, there are "no show stoppers" that would keep the shuttle fleet grounded for safety reasons, O'Keefe told reporters. He expects the flights to resume in December or early next year.
No matter what the National Aeronautics and Space Administration does, he said space flight will continue to be "inherently very risky. We'll do as much to reduce it as humanly possible."
Tests by the Columbia Accident Investigation Board suggest that a barely visible crack in a wing heat shield could have brought down the space shuttle, O'Keefe said. If such a small crack could cause a catastrophe, he said, it would force NASA to adopt extreme inspection measures for the space shuttle.
A suspected prime cause of Columbia's loss is damage from a chunk of insulation foam that smashed into the left wing 81 seconds after the launch in January. The investigation board conducted tests in San Antonio last week that mimicked this collision. They found that when a 1.6 pound chunk of foam is hurled against heat shield panels at 523 mph, it can cause hairline cracks.
O'Keefe said the cracks created by the test are very difficult to see and this suggests that NASA will have to develop inspection techniques that are "extremely meticulous" and capable of detecting such problems.
"You've got to put your face two to three inches away to see the crack," O'Keefe said.
He said the agency is studying techniques that would allow astronauts in space to closely inspect the underside of the shuttle wing. This could include installing special foot and hand restraints on the outside of the shuttle to assist spacewalkers. Some sort of repair kit may be developed, he said.
When space shuttle flights resume, O'Keefe said launches will be limited to daylight hours so cameras can take high-resolution photos of the ascent to orbit. During Columbia's January launch, some cameras failed to capture clear views of the speeding craft. Although there were pictures of the foam insulation hitting the wing, the quality was too poor for engineers to immediately calculate the extent of the damage.
An analysis made during the flight concluded that any damage to the wing would not risk spacecraft safety. As a result, engineers did not formally request that spy satellites be used to take photographs of the potentially damaged wing or take any other actions that might have given Columbia a better chance of surviving re-entry.
O'Keefe declined to discuss whether such photos from spy satellites might have been able to detect the small crack in the wing.
"I'll let you draw your own conclusion," he said. The administrator announced earlier that future space shuttles would routinely be photographed in orbit by satellite equipment operated by another federal agency.
O'Keefe said all but one of the anticipated future shuttle flights will go to the international space station (news - web sites). The station would provide a refuge for the astronauts and a platform to closely inspect any suspected damage. The sole exception, he said, is a late 2004 flight planned to maintain the Hubble Space Telescope (news - web sites). Shuttles that fly to the Hubble cannot also fly to the space station on the same mission.
The board's heat shield tests showed that the foam impact was enough to slightly open seams between the heat shield panels and cause small cracks. The theory is that this may have been enough to allow superheated gas during re-entry to enter the hollow wing and melt it from within.
The board is expected to issue a final report next month.
O'Keefe said his agency will "comply fully without any equivocation" to the board's recommendations.
Columbia came apart over during its return to Earth on Feb. 1, killing the seven astronauts on board and scattering debris over parts of Texas and Louisiana. The three remaining space shuttles were grounded.
foreverfree
I guess that scratches any missions to the sun.
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