spacetoday.net: Astronauts test tile repair techniques on EVA

Posted: Fri, Mar 21, 2008, 9:47 AM ET (1347 GMT)
STS-123: EVA #4 (NASA)

Two astronauts successfully tested tools that could be used to repair damage to the shuttle's thermal protection system during a six-and-a-half-hour spacewalk Thursday night. Robert Behnken and Michael Foreman spent six hours and 24 minutes outside the shuttle and ISS, much of that time spent on testing a tile repair technique that uses a gooey material called STA-54, which can be squirted out of a gun to fill in damaged portions of tiles on the orbiter. The application tests went well, although engineers will have to wait until after the shuttle returns to Earth to determine the overall effectiveness of the repair technique. The spacewalking astronauts also replaced a faulty circuit breaker on the station's exterior, but were unable to rewire an electrical connector that feeds power to two of the station's gyros because the connector was stuck in place. The EVA was the fourth of the STS-123 mission, with one more EVA scheduled for Saturday night.