Meteors burn up when they hit the Earth's atmosphere. Why doesn't the space shuttle?

Meteors burning up as they enter earths atmosphere.
The force of air surrounding the meteor as it enters the earth's atmosphere causes it to burn up. Adastra / Getty Images

­When a small ­meteor enters the Earth's atmosphere, it goes from traveling through a vacuum to traveling through air. Traveling through a vacuum is effortless -- it takes no energy. Traveling through air is another story.

A meteor moving through the vacuum of space typically travels at speeds reaching tens of thousands of miles per hour. When the meteor hits the atmosphere, the air in front of it compresses incredibly quickly. When a gas is compressed, its temperature rises. This causes the meteor to heat up so much that it glows. The air burns the meteor until there is nothing left. Re-entry temperatures can reach as high as 3,000 degrees F (1,650 degrees C)!


Obviously, it would not be good for a spacecraft to burn up when it re-enters the atmosphere! Two technologies are used to allow spacecraft to re-enter:

  • Ablative technology
  • Insulating tile technology

In ablative technology, the surface of the heat shield melts and vaporizes, and in the process, it carries away heat. This is the technology that protected the Apollo spacecraft.

The space shuttles are protected by special silica tiles. Silica (SiO2) is an incredible insulator. It is possible to hold a space shuttle tile by the edge and then heat up the center of the tile with a blow torch. The tile insulates so well that no heat makes it out to the edges. This page discusses the tiles:

Aerobraking tiles are produced from amorphous silica fibers which are pressed and sintered, with the resulting tile having as much as 93% porosity (i.e., very lightweight) and low thermal expansion, low thermal conductivity (e.g., the well known pictures of someone holding a Space Shuttle tile by the corners when the center is red hot), and good thermal shock properties. This process can be readily performed in space when we can produce silica of the required purity.

These tiles keep the heat of re-entry from ever reaching the body of the shuttle.


Frequently Asked Questions

How do spacecraft manage the intense heat generated during reentry without burning up?
Spacecraft manage the intense heat generated during reentry through the use of specialized heat shield technologies. Ablative technology allows the heat shield's surface to melt and vaporize, carrying away heat in the process. Another method involves insulating tiles made from silica, which are incredibly effective at insulating against the heat, ensuring it does not reach the spacecraft's body.
What are the key differences between the heat experienced by meteors and spacecraft during atmospheric entry?
The key differences lie in speed and protective measures. Meteors enter Earth's atmosphere at very high speeds without any protective technology, causing rapid compression and heating of air in front of them, which burns them up. Spacecraft, however, are equipped with heat shields that absorb, reflect or dissipate the heat generated during reentry, preventing them from burning up.