The European Space Agency is working on a project to settle people on the Moon and on Mars by 2032. To protect the settlers from harmful cosmic radiation ESA is developing a magnetic shielding building upon tokamak divertor physics.

Fusion spin offs help Star Trek “plasma shields” become a reality

Dr Ruth Bamford*

The pursuit of fusion will provide society with more than just an endless supply of eco-friendly energy for the generations to come. The technical know-how needed to achieve magnetically confined fusion may be the only way that future astronauts will be able to survive in the harsh environment in space.

Following NASA’s lead, the European Space Agency (ESA) has set an objective with its AURORA programme, to put people on the Moon and then onto Mars by 2032. This will take astronauts beyond near Earth orbit for the first time since the Apollo programme. It is well known that Space Weather, in the form of energetic particles from solar storms, regularly causes problems with satellites and communications around the Earth. Many of these storms would be fatal to humans in space craft. Heavy shielded compartments are impractical on long duration space flights and for those living on Moon and Mars bases, since the ‘drip-drip’ of cosmic radiation has been determined to be just as damaging to the health of the astronauts as large solar storms.

The writers of Star Trek correctly realised that any spacecraft containing humans would need protection from the hazardous effects of cosmic radiation. However the concept of a ‘deflector shield’ to protect the space craft is not just science fiction. The Earth would not be habitable if it were not for the magnetic field that creates a plasma barrier at the magnetopause. The supersonic plasma from the Sun hits the Earth’s magnetic field, creating a plasma transport barrier. The majority of the hazardous solar energetic particles are deflected around the Earth’s magnetosphere, skipping off towards interplanetary space behind the Earth.

A laboratory experiment is being built jointly between the Space Science Department at the Rutherford Appleton Laboratory and University of York in the UK to test the viability of creating a mini-magnetosphere around a “space craft” to expel the hazardous “solar wind” plasma and cosmic radiation, creating a plasma barrier or plasma shield. The experiment will build upon equipment originally intended to study tokamak divertor physics.

The concept has much in common with magnetically confined fusion. In fusion the aim is to hold a plasma away from a vacuum vessel wall that is essentially at room temperature. In essence the magnetic fields hold a plasma in, conversely the mini-magnetosphere uses a plasma transport barrier the other way around to keep the solar wind plasma out, away from the humans in a space craft.

Thus the UK team hopes to make use of the huge database of knowledge on plasma confinement and control to aid the next “small step for man” onto other worlds, illustrating that the pursuit of fusion will be paying dividends to society even before the first reactor is built.

*Dr Ruth Bamford works at the Space Plasmas Group, Space Science & Technology Dept, Rutherford Appleton Laboratory (RAL), Chilton, Didcot, U.K. She did her PhD at Culham and then worked as a post-doc research assistant on Reverse Field Pinch HBTX, COMPASS, START and JET. Her colleague, Professor Robert Bingham, is a plasma physics theoretician who also worked on magnetic confinement fusion at JET. Other members of the “Star Trek” research group are Tom Todd, Chief Engineer at JET and now working part time on a consultancy contract for RAL, Dr. Kieran Gibson, a PhD from JET and Professor Howard Wilson, a former UKAEA scientist who is now building up the plasma physics group at York University. Inquiries: