Space Debris Streaking Toward Space Station

NASA officials are closely tracking space debris from a 3-year-old European rocket that is expected to come within two miles of the International Space Station Sept. 4. If the 204-square-foot chunk from an Ariane 5 rocket body comes any closer to the ISS, NASA may be forced to maneuver the space station out of the way to avoid a collision.

If the ISS is forced to fire its thrusters to avoid the space flotsam, the maneuver would take place after a scheduled Sept. 3 spacewalk. NASA officials stressed the ISS and the space shuttle Discovery, which is currently docked at the space station, are in no immediate danger.

Since the Russians successfully launched Sputnik 1 in 1957, more than 4,600 space missions have been conducted worldwide, leaving behind not only a legacy of space exploration but also a swirling mass of debris: defunct spacecraft, derelict launch vehicle orbital stages, intentional refuse, and the debris of more than 200 satellite explosions and collisions.

The most recent space collision, a February smashup of an Iridium communications satellite and an inactive Russian satellite, added another nearly 900 pieces of debris and has raised questions about the safety of future space travel. Last year, NASA twice maneuvered robotic spacecraft to avoid collisions and, more recently, the ISS had to change orbits to avoid being smacked by 10-year-old debris from a Chinese satellite launch.

"The space environment is not safe-it might be fairly characterized as an environment in which everything is trying to kill you and your spacecraft," Dr. Scott Pace, director of the Space Policy Institute at George Washington University, told the House Subcommittee on Space and Aeronautics in April.

The Air Force told the lawmakers it is currently tracking 19,000 objects in space: 1,300 active payloads and 7,500 pieces of space junk. Lt. General Larry James, commander of the Joint Functional Component Command for Space, estimated that the number of active satellites will grow to 1,500 within the next 10 years and the overall number of tracked objects could grow to 100,000 with the use of better space sensors in the U.S. Space Surveillance Network.

"However, there will still be potentially lethal objects in space too small to be tracked by the Space Surveillance Network," he said.