Astronauts Complete Shuttle Heat Shield Inspection Test

The seven-astronaut crew aboard the space shuttle Endeavor performed today the final heat-shield verification using the standard NASA sensor-laden inspection pole before Friday's attempt to land at the Kennedy Space Center, in Cape Canaveral, Florida. The stakes are very high, so the crew took their time wielding the observation instrument under the belly and wings of the spacecraft, looking for any damage, no matter how small, that might have come to the heat shield. The construct is designed to sustain the fiery temperatures of atmospheric reentry, but can only do so if it is intact, Space reports.

Having undocked from the International Space Station (ISS) yesterday, the craft is currently on its way home, circling the Earth until the right landing window opens up. The late inspection has become a standard part of shuttle flight since the 2003 space shuttle Columbia accident, which was lost with its entire crew due to damage the heat shield had sustained during its flight in low-Earth orbit. Micrometeorites and other types of space junk, such as debris from satellites already in orbit, can cut through the shuttle like knife through butter, as they travel at speeds of thousands of kilometers per hour.

The check-up is also currently performed immediately after the shuttles reach their orbit, so as to ensure that no damage was caused to the shield during take-off. Endeavor went through this assessment on July 15th, after it finally launched from the KSC. “We do pretty much the exact same thing on this day to make sure that we haven't had any damage while we're on orbit from micrometeorites,” Mark Polansky, who is the commander of Endeavor for the STS-127 assembly mission, explained in a NASA interview.

“We have not tracked anything unusual that has happened during the joint mission so we expect to see a clean vehicle when we inspect it,” Endeavor Flight Mission Operations Representative Annette Hasbrook said late on Tuesday, during a press briefing. If all goes according to plan, and the weather maintains clear, the shuttle will land safely on a KSC strip at around 10:47 am EDT (1447 GMT) on Friday.

Meanwhile, back on the ISS, Commander Gennedy Padalka had to take manual control of the incoming Progress 34 unmanned resupply spacecraft, whose automated control systems failed. The capsule was in the end docked on the Zvezda module at 7:12 am EDT (1112 GMT) Wednesday morning. It carries science gear, food, water, spare parts, oxygen and fuel supplies for the station, and it is part of the regular ISS resupply program in which all nations that built the $100-billion station participate.