Plasma rockets in space

Claire Concannon meets GERALDINE, the Gigantic and Extremely Radical Atmosphere-Lacking Device for Interesting and Novel Experimentation. Plus, a team of scientists and engineers designing plasma rocket thrusters for space travel with super-conducting magnets.

GERALDINE loiters at one end of the giant lab space. Metal, shiny, round and very large, she's been purposely built to help scientists and engineers test plasma rocket thrusters in the vacuum environment of space.

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New frontiers

As senior scientist Dr Ben Mallett explains, GERALDINE's full name is the Gigantic and Extremely Radical Atmosphere-Lacking Device for Interesting and Novel Experimentation. And you can't really get more novel than the current project he is working on. It's the Paihau - Robinson Research Institute's first foray into space, and they are looking to test a brand-new superconducting magnet and flux pump design to see if it can make the plasma rockets more efficient.

Plasma rockets

Actually, the full and correct name is 'applied-field magneto plasma dynamic thrusters'. These kinds of rockets don't produce a huge amount of force - for some, the thrust they produce is equal to the weight of a piece of paper on your hand. However, they are extremely efficient. In the frictionless vacuum of space, over time, they can help spacecrafts build up great speeds and travel long distances.

Plasma is charged gas, and in these kinds of electric space thruster, electromagnets are used to direct the plasma so that it fires out the back and pushes the rocket forward. But the weight and power requirements of current magnets used in these thrusters is a barrier.

Enter Paihau - Robinson, known for their work with high-temperature superconducting magnets. Superconducting materials conduct electrical current with no resistance, so they can create very powerful electro-magnets when a current is passed through them. They do come with baggage though - a cryocooler to keep the magnet at -200oC and a flux pump to send current through the magnet to power it up. All of these parts need to be carefully designed and then tested.

But space is tricky....

There's a lot to think about when making equipment to be used in space. There's the shaking of everything as it gets launched through the atmosphere and then there's the lack of atmosphere once it's up there - the vacuum, the radiation, the different temperature effects - all have to be considered. …

Go to this episode on rnz.co.nz for more details