Engineers unveil new plasma beam tech to clean up space debris

28 Sep 2018

Image: Leo_B/Shutterstock

A team of Japanese and Australian researchers is attempting to clean up the Earth’s orbit of space debris using new plasma beam technology.

One of the greatest challenges to humankind becoming a true spacefaring species is not just the technical challenges of rocketry, but our inability to clean up after ourselves.

For more than 60 years now, humans have launched satellites and spacecraft into orbit and to the moon. Over time, though, these have either been retired or lost to accidents, resulting in our orbit being filled with space debris. Current estimates suggest that there could be as many as 166m objects ranging in size from 1mm to 1cm, each of which could be a lethal bullet for any spacecraft in Earth’s orbit.

Now, in an effort to help clean up some of this mess, a team of researchers from Tohoku University in Japan and the Australian National University has proposed new technology using plasma beams.

Diagram of how the plasma beam technology works.

Schematic of a magnetic nozzle helicon plasma thruster) having two open source exits and photographs of the three operation modes in the laboratory test. Image: Kazunori Takahashi

‘This discovery is considerably different to existing solutions’

While different methods have been suggested, this latest research is based on the ion beam shepherd method that uses a plasma beam ejected from a satellite to force an object into Earth’s atmosphere, where it will burn up.

However, the downside of this technology is that the plasma beam also accelerates the satellite in the opposite direction, making it difficult to stay close to the debris. Attempts to remedy this include adding two propulsion systems on the satellite to maintain its position, but at the cost of its size and weight.

“If the debris removal can be performed by a single high-power propulsion system, it will be of significant use for future space activity,” said associate professor Kazunori Takahashi, who led the research.

To achieve this, the Japanese and Australian research team demonstrated a helicon plasma thruster. The bi-directional ejection of plasma plumes from the single plasma thruster was precisely controlled with a magnetic field and gas injection, all while maintaining zero net force to the thruster and satellite.

“The helicon plasma thruster is an electrodeless system, which allows it to undertake long operations performed at a high-power level,” said Takahashi. “This discovery is considerably different to existing solutions and will make a substantial contribution to future sustainable human activity in space.”

Colm Gorey was a senior journalist with Silicon Republic