Aerospace Team Helps Develop "Black Box" for Space Debris

EL SEGUNDO, Calif. (7/3/02) -- What goes up must come down. When it comes to satellites and other objects launched into space, it's hard to think of them returning to Earth. Don't they just stay up there forever?

In fact, many spacecraft, or pieces of them, do return to Earth, "although we may not tend to think that they do," says Dr. Bill Ailor, director of The Aerospace Corporation's Center for Orbital and Reentry Debris Studies (CORDS), which is dedicated to researching, tracking, and analyzing spacecraft in orbit as well as the pieces that return to Earth once spacecraft have completed their lifecycles in space.

To get a better handle on just where this "space junk," as Ailor calls it, is going to land on Earth, CORDS is working with the Space and Missile Systems Center to develop a black box similar to the flight data recorders found on commercial aircraft.

A black box may one day give researchers clues about changes in material temperatures and loads on spacecraft as they reenter the Earth's atmosphere, and help determine the area or "footprint" of space debris when it lands on Earth.

Surviving pieces of varying sizes can be spread over hundreds of miles. Many factors, including atmospheric conditions and the aerodynamic characteristics of the object, influence the footprint's location.

"Data obtained using a black box could provide clues as to how changes in materials and construction might prevent large pieces of space debris from littering the planet," Ailor explains. Aluminum, for example, has a low melting temperature and is reduced to small droplets by the extremely high temperatures that result during reentry.