Japan launched a new spacecraft to the International Space Station (ISS) on Friday, December 9, which aside from delivering vital cargo will be testing out a revolutionary method to remove space debris from orbit.
The unmanned spacecraft is called Kounotori 6, the sixth H-II Transfer Vehicle (HTV) launched by the Japanese Space Agency (JAXA). It’s due to arrive at the ISS this Wednesday, where it will remain docked for about five weeks.
On board the spacecraft are a number of supplies, including water, spare parts, and new experiment hardware. The launch was all the more welcome as the last unmanned cargo launch to the ISS, Russia’s Progress spacecraft, failed on December 1, although the crew was not in danger of running out of supplies.
What’s most interesting about this JAXA mission, though, is what will be happening after it completes its cargo mission. After Kounotori undocks, it will be performing an experiment in Earth orbit to practice removing space debris.
The spacecraft is going to unfurl a tether measuring about 700 meters (2,300 feet) long, called the Kounotori Integrated Tether Experiment (KITE). This is an electromagnetic tether (EDT), and at the end is a mass weighing 20 kilograms (44 pounds). A current will run through the tether, and a combination of Earth’s magnetic field and electric current is expected to keep it taut.
The tether is designed to produce atmospheric drag, creating a noticeable pull on the spacecraft. The idea is that this technology could be used on space debris in the future to drag it out of orbit.
It’s estimated that there are millions of pieces of paint fleck-sized debris in orbit, tens of thousands of pieces of space debris larger than a tennis ball, and thousands weighing more than 100 kilograms (220 pounds). We can’t do much about the smaller debris at the moment, but for the bigger pieces ideas like this could be used to help remove them from orbit.
JAXA is planning to run the experiment for about a week, after which Kounotori will be de-orbited and burn up in Earth’s atmosphere.