Astronauts on the first space shuttle flight since the Columbia tragedy will practice three methods for patching holes in orbit and have another two repair kits on hand in case their ship is actually damaged by launch debris this spring.
In announcing the decision Friday, NASA said some of the hole-plugging techniques would almost certainly be tested on the second post-Columbia mission as well, later in the year.
On Thursday, the seven astronauts who will take off aboard Discovery as early as mid-May said they still were waiting to hear which repair techniques they would fly. At the end of the day, shuttle managers decided to put all five options on board, but have the crew test only three.
Top NASA officials will make a final ruling on the matter next Friday.
None of the five options could repair a hole as big as the one that crippled Columbia’s left wing and led to the ship’s destruction over Texas on Feb. 1, 2003, and the deaths of seven astronauts. A chunk of insulating foam from the external fuel tank caused that crevice.
In fact, none of the repair options is certified or even close to being perfected, and analysis continues even now. That is why it’s taken so long for engineers to decide which techniques to test aboard Discovery.
Two of the repair kits will be demonstrated out in Discovery’s open cargo bay by a pair of spacewalkers, said NASA spokesman Kyle Herring. One is geared toward fixing dings and other minor damage in thermal tiles, by applying what is essentially thick paint. The other involves a small caulking gun for fixing cracks in wing panels.
Engineers believe cracks and dings would be the most likely type of damage that Discovery might encounter at liftoff, rather than the type of dinner plate-size hole that doomed Columbia.
Another wing-repair technique, for plugging larger gashes, will be demonstrated inside the crew cabin, Herring said.