Space shuttle tile repair training. NASA astronaut training in the repair of the thermal tiles used on the US space shuttles. An injection tool is being used to apply the repair material (orange). The training is taking place in free-fall on a flight of a KC-135 aircraft. Thermal tiles are used on space shuttles to protect them from the heat of re-entry into Earth's atmosphere. Following the break-up of the shuttle Columbia during re-entry in February 2003, due to damage to its thermal tiles, the space shuttles are examined in orbit after each launch. Several in-flight repairs have taken place since the space shuttles resumed service. Photographed on 12 August 2003.