Space Cleanup Project: Testing the Novel Plasma Brake Concept

Thursday - October 5 2023, 04:27 UTC - 1 year ago

ESTCube-2, a tiny satellite built by Estonian students, will be launched later this week to test the ‘plasma brake’ concept, a novel technology that could help clean up the space junk orbiting our planet. The project is both a technological and educational experiment, as it was designed and built by 600 students. The satellite will deploy a 50-meter-long wire made of four aluminum strands, each as thin as a human hair, to interact with the charged particles in space. The wire is designed to be resilient against micrometeorites and other hazards.

A tiny satellite made by Estonian students will soon be launched into space with a big mission: to test a novel technology that could help clean up the space junk orbiting our planet.

The satellite, called ESTCube-2, is the size of a shoebox and weighs only 4 kg. It will hitch a ride on Europe’s Vega VV23 rocket, scheduled to lift off later this week from Europe’s Spaceport in French Guiana.

The main goal of ESTCube-2 is to demonstrate the ‘plasma brake’ concept, a type of electric sail (E-sail) that uses a long, thin wire to interact with the charged particles in space. The plasma brake was invented by Pekka Janhunen of the Finnish Meteorological Institute (FMI), who envisioned it as a way to explore the Solar System without fuel. By deploying a wire that is positively charged by a solar panel, a spacecraft could harness the force of the solar wind, a stream of protons and electrons that flows from the Sun.

However, near Earth, where the planet’s magnetic field blocks the solar wind, the plasma brake can do the opposite: it can slow down a satellite by repelling the plasma in the ionosphere, an electrically active layer of the atmosphere. This would cause the satellite to lose altitude and eventually burn in the atmosphere, avoiding becoming space debris.

Space debris is a growing problem that threatens the safety and sustainability of space activities. There are millions of pieces of human-made objects orbiting Earth, ranging from defunct satellites and rocket stages to nuts and bolts. These objects can collide with each other or with active satellites, creating more debris and potentially damaging or destroying valuable infrastructure.

As per the ESA's press release, the plasma brake could offer a cheap and straightforward solution to deorbit satellites at the end of their lives, reducing the risk of space collisions and clutter. It could also remove existing debris by attaching it to them with a robotic arm or a harpoon.

ESTCube-2 will test this idea by deploying a 50-meter-long wire made of four aluminum strands, each as thin as a human hair. A 3-watt solar panel will charge the wire, creating a 100-volt potential difference with the surrounding plasma. The satellite will measure the force and the current generated by the wire and its effect on the orbit. The wire is designed to be resilient against micrometeorites and other hazards that could snap it. It has a net-like structure with two parallel and two zigzagging wires that are bonded together.

"The plasma brake is an exquisite and simple technology, but it has never been tested in orbit before,” said Pekka Janhunen. “We are very excited to see how it works and what we can learn from it.” .

ESTCube-2 is not only a technological experiment but also an educational one. It was built by more than 600 students from different levels of study, mainly from the University of Tartu and its Tartu Observatory. The project was led by the student organization Tudengisatelliit.

The satellite also carries other payloads, such as micro cameras to monitor Estonian vegetation and compare it with data from ESA’s Copernicus Senti/Altimeter missions.