Wes Cox is well on his way to realising his childhood dream of working at NASA.

Cox, a PhD candidate at the Australian National University, is conducting research on a plasma propulsion device that could provide the technological push for long-distance manned space missions, perhaps even to Mars.

The device, the helicon double layer thruster (HDLT), was invented by Christine Charles, of the Space Plasma, Power & Propulsion Group at ANU's Research School of Physical Sciences and Engineering.

It accelerates plasma - a gas of ionised, or charged, particles - across a potential difference, providing thrust. The plasma is created by heating the gas with radiowaves.

"While a chemical thruster generates strong thrust, it only sustains it for seconds or minutes," Cox says. "The HDLT potentially provides a much weaker thrust but can sustain it for months or years."

"Over the lifetime of a long mission, this constant small thrust allows the craft to reach greater speeds than chemical rockets, which provide an initial immense speed but have to cruise for the remainder of the mission."

"And since it's potentially more efficient than a chemical rocket, the HDLT can provide thrust at a higher efficiency and consume less fuel - a critical factor in space missions."

Cox is investigating the effect of magnetic fields on the thruster. "I use a variety of probes to study the behaviour of the plasma under various conditions in the hope of optimising it for space flight one day."

Cox, who grew up near Bathurst in rural NSW, did his BSc (Honours) at ANU. He was originally attracted to the university by its strength in astrophysics, but later wanted to switch to applied science.

He divides his time between programming, data analysis and lab work - between "nuts and bolts and thinking about the big picture".

And the future? "I'd like to go to NASA. It would be pretty sweet. It's a childhood dream."