MUNCHING TO MARS

Arc welding principles harnessed to fuel space craft

A ROCKET THAT FUELS ITSELF by eating space junk is being prepared for its first space mission. The Neumann Drive was developed by Australian-based start-up Neumann Space and feeds on a variety of metals to power itself over long distances.

The rocket has been identified for its potential to remove fragmented rocket parts, defunct spacecraft and other space junk adrift in space.

It is joining an Airbus mission to the International Space Station (ISS) in 2019 to test its real-world capabilities and collect data. The rocket will be tethered to the ISS for the year-long trial before a freeflight model is tested.

Neumann Space Founder and CTO Patrick Neumann says floating space junk was an increasingly serious issue that put many satellites and space missions at risk.

“The system is useful for different things: one option is a tugboat or two-truck device that can go around and focus on cleaning up junk, which means people who own defunct satellites have a lot less risk of hitting an active one. Another option is using the system’s short, sharp thrusts of power to keep stations and satellites doing their thing and staying in orbit.”

The drive works similar to an arc welder which creates thrust by eroding material at the tip of a metal cathode. Once its material gets evaporated and ionised, it is spat down range, causing a pulsating thrust and propelling the rocket forward, similar to the way a bullet leaves the barrel of a gun.

Researchers have found that magnesium is the optimal fuel source, but materials such as tungsten, chromium and carbon have been successfully trialled.

Neumann says his research group is still working on developing a way to capture and reprocess space debris into a usable resource for the rocket when it is tested in space.

“A lot of the metals we are using already have aerospace applications and many of the structural parts of the (space) junk are made out of those metals.”

According to the European Space Agency (ESA) there are about 18 000 large objects in orbit and more than 90 per cent is space junk caused by more than 250 spacecraft explosions. Millions of smaller bits of debris floating in space are too small for radars to track.

A collision with a piece of material only a few millimetres in size is enough to alter a satellite’s orbit and offset its orientation. This was evident when a small space article hit the solar panel on the Copernicus Sentinel-1a satellite late last year, which resulted in a small power reduction. According to the ESA, if the particle had been much bigger the repercussions would have been far more severe.

The Neumann Drive can produce thrust at more than 10 000 seconds for 1 pound of thrust when magnesium is used as fuel. This is significantly better than gridded iron thrusters, which max out at about 3 500 seconds.

Neumann says its efficiency record made it powerful enough to send a mission from earth’s lower orbit to the lower Mars orbit and back without needing to refuel. Placing metal fuel stops at various points in space could further increase the reach of the rocket, leading to deeper space exploration. – Source: The Lead