Return trip to Mars, please!
It’s a truly ambitious goal: The plan is to establish an oxygen production plant on Mars that will make it possible to send manned missions to the red planet.
In his well-researched, bestselling novel “The Martian”, Andy Weir describes why a manned mission to Mars will crucially depend on a reliable supply of oxygen. Following a dust storm, it becomes necessary to abort a Mars mission. Engineer and botanist Mark Watney is left stranded on Mars as a result of a tragic accident and tries to survive on the planet until the next mission arrives. The first thing Watney uses to survive is the “fuel generator” from the Mars Ascent Vehicle, or MAV. More properly a “propellant generator”, the system he describes collects and compresses carbon dioxide in order to convert it to oxygen, which was presumably used as a reaction gas to burn the fuel that lifted the rest of the crew safely to orbit.
Up to now, all of mankind’s trips to Mars have been one-way, and the only crewmembers have been robots. But while NASA may not be ready for the mission described in Weir’s novel, they are making a beginning with Moxie, a 1:100 scale prototype of the MAV propellant generator to be flown on the Mars 2020 mission.
A precursor to the nuclear reactor described in The Martian, Mars 2020’s radioisotope thermoelectric generator (RTG) supplies Moxie with the power to convert the carbon dioxide in the Martian atmosphere into oxygen. Sometime in the 2030s, NASA plans to establish a full-size oxygen plant on Mars, together with a power plant and an empty habitat, to generate oxygen and store it cryogenically in large tanks in preparation for arrival of a human crew.
In essence, Moxie uses the reverse of the principle behind the fuel cell. Conversion of the gas takes place in a stack of Solid Oxide Electrolysis Cells (SOEC). The US company Ceramatec has been awarded the contract for building the prototype SOEC stacks, and Plansee is supplying the interconnects for the stacks. If everything goes according to plan, Moxie will produce 20 grams of oxygen per hour
and spend at least 50 days working on Mars.