14 DAY TRIAL // All NASA shuttles are protected upon atmospheric reentry by a ceramics-based heat shield, which is able to handle the thousands of degrees that heat up the spacecraft' underbellies. For all their resilience, these heat shields are extremely sensitive, and even minor impacts can cause very dangerous dents. After the 2003 Columbia accident, which saw the loss of the shuttle and the deaths of seven astronauts, the American space agency has set in place safeguards, to ensure that such an event never happens again.
The new safety protocols say that space shuttles need to be inspected for damage on two separate occasions – the first time the day after take-off, and the day before landing. The procedure is conducted via a sensor-laden pole, which is manipulated through the spacecraft's robotic arms, and passed under the wings and the nose. The images and readings that are captured are then sent to NASA, which has sufficient time to analyze them before giving the final verdict. All shuttles currently have an emergency heat-shield repair kit onboard for precisely this type of situation.
This protocol was also carried out for space shuttle Atlantis yesterday. The spacecraft took off on Monday from the Launch Pad 39A facility at the Kennedy Space Center (KSC), and is currently heading towards the International Space Station (ISS). It carries six astronauts and a large number of spare parts for the orbital outpost. Its crew conducted the first mandatory heat shield inspection on Tuesday. Though the procedure was scheduled to last for more than six hours, it was completed sooner, as astronauts moved ahead of schedule. The craft will meet up with the ISS today at 1:53 am EST (1653 GMT).
“If there's been any impacts, things that have come off the tank or some spare debris, or something has hit something, we can take a look at it with the sensor packages and try to determine if it's something that is kind of benign or something worth fixing with [a spacewalk]. And so we'll survey the port wing, the starboard wing and the nose cap and then make sure that everything is safe,” Atlantis mission specialist Leland Melvin said in a preflight interview, quoted by Space.
“It's been very refined, well-scripted, developed over numerous missions, a procedure that we go through now. It's a long day. It's a lot of intensive arm ops obviously but what we do is we rotate our crew members through to keep 'em fresh,” Charlie Hobaugh, the commander of the STS-129 flight to the ISS, added. The mission is scheduled to spend more than 11 days in space, and also to perform a number of three spacewalks during this time, which will see the materials in Atlantis' cargo bay being removed, and then placed in special storage compartments on the outer hull of the station.