Space Junk: Japan Sends Electrodynamic Tether Into Orbit To Slow Down, Remove Space Debris

Scientists estimate that there may be over 100 million pieces of space debris— most of which are too small to be monitored — currently floating in orbit. This orbital junk can travel at speeds of up to 17,500 miles per hour — fast enough to cause serious damage to satellites and even the International Space Station (ISS).

“Debris hitting debris creates more debris, so you have this cascade effect and end up with so much space debris that it becomes a real danger to operational satellites and new launches,” Steve Gower, general manager of the Space Environment Research Centre in Canberra, Australia, told Bloomberg recently. “Every time we launch a satellite, we need to plan a path to avoid space junk.”

On Friday, in a step aimed at clearing up the clutter in Earth’s orbit, Japan launched a cargo ship carrying an electrodynamic tether made of aluminum and stainless steel. The cargo ship — named Kounotori, which means stork in Japanese — lifted off from the Tanegashima Space Center in southern Japan at 8:26 a.m. EST on Friday. It will dock with the Earth-facing side of the space station’s Harmony module, where it will spend more than five weeks.

The tether, which the Japan’s space agency made with the help of a fishnet company, would use the electricity generated by its motion through Earth’s magnetic field to slow the debris down and push it into a lower orbit, where it would then enter the atmosphere and burn up.

“The tether uses our fishnet plaiting technology, but it was really tough to intertwine the very thin materials,” Katsuya Suzuki, an engineer at the Japanese fishnet manufacturer Nitto Seimo — a 106-year-old company that developed the mesh material, told Agence France-Presse. “The length of the tether this time is 700 meter (2,300 feet), but eventually it’s going to need to be 5,000 to 10,000 meter-long to slow down the targeted space junk.”

The electrodynamic tether is not the only idea that Japan is mulling over to get rid of space debris. Last year, in a study published in the journal Acta Astronautica, researchers from Japan’s Riken research institute proposed a method that basically involves blasting an estimated 3,000 tons of debris through a fiber optic laser mounted on the ISS.