ESA accelerates towards a new space thruster

December 13, 2005
Helicon reactor in operation. Credits: LPTP, Ecole Polytechnique

ESA has confirmed the principle of a new space thruster that may ultimately give much more thrust than today's electric propulsion techniques. The concept is an ingenious one, inspired by the northern and southern aurorae, the glows in the sky that signal increased solar activity.

"Essentially the concept exploits a natural phenomenon we see taking place in space," says Dr Roger Walker of ESA's Advanced Concepts Team. "When the solar wind, a 'plasma' of electrified gas released by the Sun, hits the magnetic field of the Earth, it creates a boundary consisting of two plasma layers. Each layer has differing electrical properties and this can accelerate some particles of the solar wind across the boundary, causing them to collide with the Earth's atmosphere and create the aurora." In essence, a plasma double layer is the electrostatic equivalent of a waterfall. Just as water molecules pick up energy as they fall between the two different heights, so electrically charged particles pick up energy as they travel through the layers of different electrical properties.

Researchers Christine Charles and Rod Boswell at the Australian National University in Canberra, first created plasma double layers in their laboratory in 2003 and realised their accelerating properties could enable new spacecraft thrusters. This led the group to develop a prototype called the Helicon Double Layer Thruster.

The new ESA study, performed as part of ESA's Ariadna academic research programme in association with Ecole Polytechnique, Paris, confirms the Australian findings by showing that under carefully controlled conditions, the double layer could be formed and remains stable, allowing the constant acceleration of charged particles in a beam. The study also confirmed that stable double layers could be created with different propellant gas mixtures.

"The collaboration has been absolutely excellent," says Dr Pascal Chabert, of Laboratoire de Physique et Technologie des Plasmas, Ecole Polytechnique. "It has been a real kick-off for me and has given me lots of new ideas for plasma propulsion concepts to investigate with the Advanced Concepts Team. The new direction for our laboratory had led to a patent on a promising new electric propulsion device called an Electronegative Plasma Thruster."

To create the double layer, Chabert and colleagues created a hollow tube around which was wound a radio antenna. Argon gas was continuously pumped into the tube and the antenna transmitted helicoidal radio waves of 13 megahertz. This ionised the argon creating a plasma. A diverging magnetic field at the end of the tube then forced the plasma leaving the pipe to expand. This allowed two different plasmas to be formed, upstream within the tube and downstream, and so the double layer was created at their boundary. This accelerated further argon plasma from the tube into a supersonic beam, creating thrust.

Calculations suggest that a helicon double layer thruster would take up a little more space than the main electric thruster on ESA's SMART-1 mission, yet it could potentially deliver many times more thrust at higher powers of up to 100 kW whilst giving a similar fuel efficiency.

In the next steps, ESA will now construct a detailed computer simulation of the plasma in and around the thruster and use the laboratory results to verify its accuracy, so that the in-space performance can be fully assessed and larger high power experimental thrusters can be investigated in the future.

Source: ESA

Explore further: Solar cells get boost with integration of water-splitting catalyst onto semiconductor

Related Stories

New antireflective coating reduces stray light and reflections

October 4, 2016

Transparent plastic optical lenses can be manufactured cheaply and in any shape. However, a downside is that they reflect light just as much as glass does. At the K trade fair in Düsseldorf, Fraunhofer researchers are exhibiting ...

Plasma thruster tested for Mars mission

January 3, 2006

Technology invented by ANU physicists could see expeditions to Mars become a reality, with the European Space Agency (ESA) announcing it will begin full-scale trials next year.

Plasma etching pushes the limits of a shrinking world

November 10, 2011

Plasma etching (using an ionized gas to carve tiny components on silicon wafers) has long enabled the perpetuation of Moore's Law -- the observation that the number of transistors that can be squeezed into an integrated circuit ...

Recommended for you

New aspect of atom mimicry for nanotechnology applications

December 2, 2016

In nanotechnology control is key. Control over the arrangements and distances between nanoparticles can allow tailored interaction strengths so that properties can be harnessed in devices such as plasmonic sensors. Now researchers ...

Evaluation of scientific rigor in animal research

December 2, 2016

The "reproducibility crisis" in biomedical research has led to questions about the scientific rigor in animal research, and thus the ethical justification of animal experiments. In research publishing in the Open Access journals ...

Swiss firm acquires Mars One private project

December 2, 2016

A British-Dutch project aiming to send an unmanned mission to Mars by 2018 announced Friday that the shareholders of a Swiss financial services company have agreed a takeover bid.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.