orbital cleanup

Satellites currently must dodge an ever-growing gauntlet of other satellites and clouds of space debris, and this year the Pentagon has quietly upgraded its surveillance accordingly. The U.S. military announced yesterday that it now tracks 800 maneuverable satellites, compared to less than 100 prior to a February collision between an active U.S. satellite and a retired Russian communications satellite.

Having scrubbed the notoriously squalid streets of Paris spotless, the French have set their sights on a bigger clean-up project: the expanding swarm of space debris circling the planet. French spaceflight engineer Brice Santerre of the European aerospace company EADS Astrium has constructed the Aerobraking Sail for bringing defunct satellites out of orbit.

When a satellite dies, the built-in braking system will deploy two inflatable booms, which release a pair of heat-resistant polymer “wings.” The wings increase the friction drag that slows the satellite’s orbit and allow gravity to tug it into the lower atmosphere, where it will burn up in 25 years instead of the typical 50 to 100, Santerre says.

Along with satellites and space stations, Earth is surrounded by tens of millions of pieces of floating space debris. Like any landfill, the trash is diverse, ranging from dead satellites to castaway rocket parts to flecks of paint. On average, over the past 40 years, one piece of space junk has fallen to Earth every day.