Recorded on a Kennedy Space Center tour before the launch of the last Space Shuttle mission (Atlantis), watch tour attendees pick up NASA’s 2,200 degree thermal tiles — specially designed, coated LI-900 ceramic tiles made out of 99.9% pure silica glass fibres and 94% by volume of air. (Thanks, @Bilsko.) From wikipedia

White tiles (known as LRSI) are used mainly on the upper surface and have higher thermal reflectivity. These are therefore pointed towards the sun in order to minimize solar gain.

Black tiles (known as HRSI) are optimized for maximum emissivity, which means they lose heat faster than white tiles. This property is required in order to maximise heat rejection during re-entry.

Read more about how the space shuttle thermal protection systems work and watch Dr. Ainissa Ramirez demonstrate and explain more about the 27,000 ceramic tiles on the bottom of the space shuttle:

More Material Marvels and more Space Shuttle videos in the archives.