Photo: Nasa-JPL-Caltach

Oxygen and chemicals for the first refuelling station on Mars

Tuesday 08 Nov 16


Christopher R. Graves
Associate Professor
DTU Energy
+4546 77 58 70
When astronauts first set foot on Mars in the 2030s, a ‘petrol station’ will be ready for them, with oxygen and fuel for the trip home. DTU researcher Chris Graves is one of the people tasked with making this possible.

The human race wants to travel farther into the universe, and the first step is likely to be a manned mission to Mars. However, the journey itself and the stay on the planet are sure to be tough on the international astronauts. They will have to battle freezing temperatures, sandstorms and a shortage of water—and of course, they will also need oxygen to breathe. Chris Graves, Senior Research Scientist at DTU Energy, is working with a research group at NASA to ensure that the astronauts have the capacity to produce oxygen on location, as well as sufficient rocket fuel to return home.

Oxygen is in extremely short supply on Mars, where the atmosphere comprises 96 per cent CO2, and it would be close to impossible to carry sufficient oxygen to allow the astronauts both to survive on the planet and then return to Earth. So they will have to generate their own oxygen on site, which they can do using a tried and tested technology: electrolysis.

“Here on Earth, oxygen is a byproduct when we use electrolysis to convert surplus current from wind turbines into synthesis gases for use in the chemical industry, or to make fuels. On Mars, however, oxygen will be the most important product, and the team will also need chemicals to make rocket fuel,” explains Chris Graves.

DTU Energy has been researching electrochemical electrolysis cells since the late 1980s, and is now one of the leading research institutes in the field. This is one of the reasons why NASA has called on DTU researcher Chris Graves for assistance. Another reason is that Chris Graves is an American.

Photo: JPL
The colour wonderland of Mawrth Vallis. Photo:JPL.

Danish assistance for NASA
“I already know many of the researchers involved in the various Mars projects under NASA and we have worked well together on other projects. It was really exciting when I was invited to join the project as an external partner back in 2013,” he says.

Together with the Danish professor Morten Bo Madsen from the University of Copenhagen, Chris is a member of the research group responsible for NASA’s Mars Oxygen ISRU Experiment (MOXIE).

"On Mars, oxygen will be the most important product, and the team will also need chemicals to make rocket fuel."
Chris Graves, Senior Research Scientist, DTU Energy

The group is tasked with taking existing electrolysis technology and adapting it for use in conditions on Mars —a difficult assignment that is further complicated by factors such as the low level of gravity, freezing temperatures and dust- and sandstorms on the Red Planet.

“It will be a compact machine with a host of functions. My part of the project involves converting carbon dioxide into oxygen, in the same way as you can see in the film The Martian, where an astronaut is stranded on Mars and has to find ways to make oxygen,” says Chris Graves.

Researchers in Denmark and the United States are working had to minimize the technologies for the first version of MOXIE, which must not weigh more than 12 kg or measure more than 23.9 x 23.9 x 30.9 cm. They get together regularly through weekly online meetings and at annual conferences, the next of which will be held in November at the premises of Ceramatec in Utah, USA.

The objective is to create a MOXIE unit that will be sent to Mars on NASA’s Mars 2020 Rover mission, so that it can be tested in authentic Mars conditions—freezing temperatures, dust and thin atmosphere.

“The first version only has to produce 22 grams of oxygen per hour, where we will be measuring the purity of the CO and O2 in the end product before releasing them into Mars’ atmosphere again,” explains Chris Graves.

Photo: NASA-JPL-Caltech
The moons of Mars. Photo: NASA/JPL-Caltech.

The first refuelling station on Mars
The team plans to use experience from the Mars 2020 Rover mission to build a model 200 times larger, which the timetable requires to be shipped to Mars approx. 18 months before the first astronauts set off for the Red Planet at some point in the 2030s.

This full-scale model is to land on the planet and spend months working to build up stocks of oxygen and carbon monoxide in preparation for the arrival of the astronauts, who will then be able to fill up with oxygen and rocket fuel on Mars before heading back to Earth again.

The MOXIE project is being run by the Massachusetts Institute of Technology (MIT), while the Caltech Jet Propulsion Lab and other companies in the area are taking care of the design and assembly of the unit itself.