From a space station hundreds of kilometres above the Earth's surface, there is—as DTU Professor and space instrument and technology expert John Leif Jørgensen points out—a long way to the workshop if you suddenly need a spare part that you do not have in stock. A metal 3D printer could prove to be the solution to precisely that challenge.
That is exactly why the people on the Huginn mission, headed by Danish astronaut Andreas Mogensen, will be testing a brand-new printer on the ISS. The printer has been developed for this purpose by European aircraft manufacturer Airbus for the European Space Agency, ESA. "Such a printer can produce exactly the bits you need up there," says John Leif Jørgensen.
The printer is equipped with a nozzle that spouts a stainless-steel wire. A laser beam melts the wire while the printer moves, creating the selected pattern and building the object for which the printer has been set.
"Technically it's just a small welding wire that you melt into place with a laser beam. But it will make it possible to produce complicated objects far away from a conventional production hall," says the professor.
The visit to ISS will give Airbus important insight into what changes may be needed to make the printer ready to manufacture spare parts in space on a larger scale.
Knowledge about differences provides important insight
As part of the project, the astronauts will print copies of a carefully designed 5-cm tall structure. Researchers at DTU have produce similar models on Earth. When the Huginn crew returns, the researchers will make accurate measurements of the two printed models to determine what differences there might exist between them.
"Everything made on Earth, is affected by gravity. This means that physical effects may differ along and across the gravity. One such effect is that objects are often heated and cooled differently when processed creating internal tension, which in turn may cause materials to warp. The absence of gravity on ISS will minimize such built-in tensions in the printed figures," John Leif Jørgensen explains.
