NASA has identified two cracks in the space shuttle's external fuel tank that led to the delays in Discovery's launch earlier this month.
Discovery was scheduled to take off Nov. 5 on its final mission, to the International Space Station, a flight that was delayed until Nov. 30 following discovery of a fuel leak. Tuesday morning, technicians at the space agency identified two cracks on a section of the tank’s metal exterior during removal of the external fuel tank foam insulation.
An unidentified NASA technician snapped a few high-resolution photos of the crack -- and promptly posted them on his son's blog, Gizmodo reported Tuesday evening.
The space agency acknowledged the photos and the discovery of the crack Wednesday afternoon, explaining that the external tank's cracks were discovered during draining operations following the shuttle Discovery’s launch scrub on Nov. 5.
"These are photos apparently taken from presentations to shuttle program engineers on the status of the foam crack seen after the most recent launch scrub," Kyle Herring, space shuttle program public affairs officer, told FoxNews.com.
The space agency updated its website Wednesday afternoon with additional information and images.
"They were found on the stringer, which is the composite aluminum ring located on the top of the tank’s intertank area," NASA reported. "The cracks are approximately 9 inches long. Engineers are reviewing images of the cracks to determine the best possible repair method, which would be done at Launch Pad 39A."
Similar issues have affected launch attempts during two previous shuttle missions, both in 2009. In the past, crews have repaired cracks in the external tank by removing the cracked aluminum and replacing it with a "doubler" -- a twice-as-thick section -- before replacing the foam insulation. Exact schedules and repair options still are being evaluated, NASA said.
The hydrogen gas leak was detected at around 7:30 a.m. Nov. 5 in a location known as the Ground Umbilical Carrier Plate, which is an attachment point between the external tank and a 17-inch pipe that carries gaseous hydrogen safely away from the shuttle to the flare stack, where it is burned off.
Discovery will fly an 11-day supply mission to the International Space Station to deliver a humanoid robot helper for the station crew and a new storage room for the orbiting lab. The orbiter has already faced down a series of setbacks, including a pair of gas leaks, an electrical glitch and, most recently, uncooperative weather.
The STS-133 mission will be Discovery's grand finale in space before being retired along with the rest of NASA's shuttle fleet in 2011.
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