CAPE CANAVERAL, Fla. -- NASA must come up with a way to inspect and repair a space shuttle's thermal protection system while in orbit before missions can resume, the Columbia Accident Investigation Board (CAIB) said Friday.
The announcement is the board's third finding and recommendation released to the space agency in anticipation of the final report coming out as soon as late July. It formally states what board members have been saying for several weeks and does not come as a surprise to NASA.
NASA flight controllers and engineers at the Johnson Space Center in Houston have been working on this very problem since very soon after the Feb. 1 tragedy.
A breach in the heat protection system of Columbia -- likely caused by an impact of external tank insulation foam during launch -- is what caused the loss of the vehicle and crew.
As a result, the ability to identify and repair problems with the heat protection tiles or reinforced carbon-carbon panels on the leading edge of the wings is absolutely necessary to improve safety, the board concluded.
Details of the procedures and materials to be used were not specified, but the CAIB made it clear that NASA should be ready with this capability, whether or not the mission is flying to the International Space Station.
Missions to the ISS offer a greater number of available options to pull this off, but the same capability must be in place for missions such as servicing the Hubble Space Telescope -- which doesn't circle the planet in the same orbit as the ISS.
Based in part on a previous recommendation from the CAIB, NASA has already adjusted its relationship with the National Imagery and Mapping Agency to improve its inspection options.
During Columbia's mission, NASA officials stopped an informal request for satellite imagery when it was decided that damage to the shuttle's tiles was not a flight safety risk and that such imagery wouldn't be helpful anyway.
The CAIB has taken strong exception to this mindset.
"During the STS-107 flight and investigation, the lack of repair capability was cited repeatedly, and may have been a factor in decisions made during the STS-107 mission, including the decision not to seek images which might have assisted in the assessment of damage resulting from the foam strike on ascent," the CAIB said in a statement.
NIMA will provide NASA with imagery of the shuttle in orbit from classified resources. The orbiter may be required to orient itself in certain directions during a mission so satellites can capture the best images.
Inspections might also be accomplished by spacewalking astronauts attached to jet backpacks or the end of the shuttle's robot arm, which may now have to fly on every mission, NASA spaceflight chief Bill Readdy said Wednesday at the Kennedy Space Center.
NASA also is exploring the possibility of using small robotic spacecraft equipped with cameras to fly around the shuttle and inspect its surface.
As for the repair kit itself, NASA officials say that advances in materials since the early days of the shuttle program nearly 30 years ago might make it possible to employ repairs on damaged heat tiles or composite panels.
Spacewalking procedures to apply a repair already are being discussed by NASA, with the idea that initially they'll figure out how to do it while docked at the ISS and later with the shuttle flying on its own.
"Changes in imaging and inspection capabilities, materials technology, and the access provided by the ISS have greatly improved the prospects for deploying this capability," the CAIB statement said.
Although not yet voiced as a formal recommendation, the CAIB repeated in its statement something that board chairman Harold Gehman said Tuesday, that NASA must take all practical steps to reduce the shedding of foam from the external tank while at the same time look for ways to make the thermal protection system tougher.
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