International Space Station

A key to a successful thermal protection system for the Space Shuttle depends on two things— light weight and the ability to withstand the high temperatures of reentry. Img. 2 A close-up of the underside of the orbiter. caption (Photo courtesy of NASA - www.nasaimages.org) When the space shuttle de-orbits and begins to return to Earth, it faces a serious problem due to frictional heating. Protecting the shuttle and the crew from such heat is very important. When the shuttle reenters Earth’s atmosphere at about 400,000 feet or about 122 km, it is traveling at about 25 times the speed of sound (Mach 25). It uses the friction of reentry to slow the shuttle down, but in doing so it pays a price in the form of frictional heating. Temperatures on the shuttle reach several thousand degrees. If the shuttle had a metal exterior like an airplane, it would be burn up due to the heat produced by the friction. The tiles on the shuttle provide a means for thermal protection.