Satellites, space shuttles and the International Space Station (ISS) have potentially destructive neighbors to contend with while orbiting Earth.
According to NASA, more than 20,000 pieces of space debris orbiting Earth are larger than a softball. But 500,000 pieces are the size of a marble or larger. Further, millions of pieces are so small they can’t be tracked. Traveling at speeds up to 17,500 mph, the debris are a constant concern.
NASA and the U.S. Dept. of Defense are able to track debris 2 in in diameter in low Earth orbit.
“Even tiny paint flecks can damage a spacecraft when traveling at these velocities,” according toNASA. “In fact, a number of space shuttle windows have been replaced because of damage caused by material that was analyzed and shown to be paint flecks.”
Recent collisions include a defunct Russian satellite hitting and destroying an operating U.S. Iridium commercial satellite in 2009. NASA said the collision added more than 2,000 pieces of debris to orbiting space junk. In 2007, China used a missile to destroy an old weather satellite, which added more than 3,000 pieces of debris.
But researchers from Spain’s Univ. of La Rioja, using and algorithm based on biological evolution, have developed a new method of eliminating artificial satellites in highly elliptical orbits upon mission completion.
Published in Advances in Space Research, the study involved researchers simulating a satellite’s orbit over 100 years in a few seconds. The orbit propagator software aims to find ideal conditions and instances for a satellite to re-enter the Earth’s atmosphere for safe disintegration away from other satellites.
The researcher’s method was applied to the European Space Agency (ESA)’s INTEGRAL mission, which was launched in 2002. “The simulation results suggests designing maneuvers so the INTEGRAL satellite re-enters into the Earth’s atmosphere, and subsequently disintegrates, during the period of time from September 2028 to July 2029, in a controlled way and with a cost which is reduced by the amplification of natural gravitational effects,” rather than using extensive costly propellant, said co-author Roberto Armellin.
In January, the ESA announced the INTEGRAL adjusted orbit in order to perform a safe re-entry in February 2029. ESA’s recent guidelines dictate a retired satellite must be disposed of within 25 years if it crosses into protected orbit regions. Though INTEGRAL is exempt due to its launch date, the ESA is attempting proper disposal.
“It’s allowing us to maximize the precious scientific return from this satellite, while fully meeting end-of-life and debris mitigation guidelines,” said Erik Kuulkers, INTEGRAL’s project scientist.
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