Space shuttle tires took a lot of pressure. From orbit to landing, the shuttle tires weathered temperature changes of up to 170 degrees Fahrenheit and a drop in altitude of over 200 miles in less than an hour. Altitude and temperature shifts bring changes in air pressure, which could have caused tires to leak or burst if they weren’t designed to meet the challenge.
Instead of using air, which is made up of 21% oxygen, space shuttle tires were filled with nitrogen. Unlike oxygen, nitrogen resists fire. And since its molecules are bigger than oxygen’s, nitrogen leaks out from tires more slowly, which is a big plus in the vacuum of space.
When visiting the Science Center, guests can touch the tires from Endeavour flight STS-134, which show the wear from landing on the runway.