Breathe on Mars is one of the biggest challenges to human survival on the red planet. But a plasma technology, which allows turning carbon dioxide into oxygen, may be a solution.
When we speak of states of matter, we all remember solid, liquid, and gaseous states. But they are not the only ones: there is also Bose-Einstein condensate and plasma. The latter is found, for example, in the Sun. And now a team of researchers in Portugal says that it’s also the answer to one of the greatest challenges to human survival on Mars. It seems that breathing on the red planet may be more than a dream through the transformation of carbon dioxide into oxygen, thanks to a plasmas technology.
In addition to the icy climate (on average minus 60 degrees Celsius), Mars’ atmosphere is composed of 96 percent carbon dioxide and a pressure about 150 times lower than on Earth, posing a serious challenge to the exploration and installation of space bases on the planet. But these atmospheric conditions are, on the other hand, excellent for the creation of oxygen from the decomposition of carbon dioxide (CO2), made with the use of low-temperature plasmas – says in a scientific article published in the Plasmas Sources Science and Technology journal. “Plasmas are good for almost everything that goes through our heads”, explains Vasco Guerra, from the Higher Institute of Plasmas and Nuclear Fusion (IPFN) at Higher Technical Institute (IST) in Lisbon. The researcher is the lead author of the article and is leading research on this method of oxygen production, which promises to simplify the logistics of a Martian solo mission.
And what exactly is a plasma? “We usually define a plasma as an ionized gas, in fact it’s something more than that”, explains Vasco Guerra. “In a ‘low-temperature plasma’ only a small fraction of the molecules are ionized (might be only one in a thousand, or one in a million, or even less), where electrons have a lot of energy (which allows very reactive species to be created and, for example, to dissociate molecules), but the gas temperature remains relatively low, whereby the gas heating losses are limited.” Depending on the conditions of laboratory-created plasma, a relatively low temperature means that the gas is typically between 30 and 1500 degrees Celsius: “As opposed to a ‘hot plasma’, where all atoms and molecules are ionized, as in the case of the Sun, where temperatures are much higher [in millions of degrees].”
The team – which includes not only the IPFN but also the University of Porto and the Plasma Physics Laboratory (LPP) in Paris – believes that plasma can separate carbon dioxide from oxygen more efficiently in Mars than on Earth. “It’s the plasma electrons that will induce the separation of oxygen from carbon dioxide”, says Vasco Guerra. Because they are very energetic, when they collide with a molecule of carbon dioxide, the electrons transfer a part of their energy to that molecule, that can break it or make it vibrate, the first step of a mechanism that also leads to the separation of this molecule.
And why is effectiveness may be greater on Mars? First, because the lower atmospheric pressure of the planet would allow creating plasmas without the vacuum pumps (to lower the pressure) nor the compressors (to increase the pressure) needed on Earth. Then, because the temperature is ideal for the plasma to more easily break one of the chemical bonds that keep carbon and oxygen tightly attached while preventing carbon dioxide from re-forming.
Human missions, but not only
The proposed method may, on one hand, provide oxygen for breathing and, on the other hand, allow the production of fuels to return to Earth since carbon dioxide and oxygen can be used to make blends for the propulsion of space vehicles. “It would minimize the risks for the crew and the mission, as well as reduce logistics, allowing for increased spacecraft shield and self-sufficiency. In addition, it would also reduce costs by requiring fewer launch vehicles to complete the mission”, says on the scientific paper, which states that “Mars is the next step in the journey to the Universe.” And he points out, as examples of that will, the European Space Agency (ESA), and NASA’s Red Dragon program in partnership with SpaceX, the company of Elon Musk, the billionaire who already has said he wants to colonize Mars with one million people in less than 100 years.
In March 2016, for the first part of ExoMars, the Trace Gas Orbiter probe and the Schiaparelli landing module was launched, but the latter eventually crashed into Martian soil, considered a cemetery of space devices. Before this end, the company Airbus Defense and Space began to build the rover for the second part of the program. And last year, the then President of the United States, Barack Obama, said he wanted to send humans to Mars by 2030 and make them return to Earth safely. In April of this year, Donald Trump, the current US President, confessed that he would like to see Americans on Mars from three to seven years from now. And earlier this month, he instructed NASA to take astronauts to the moon to look at Mars. Vice President Mike Pence had already spoken about the change of plans. “NASA astronauts will return to the Moon – not only to leave footprints and flags but to build the bases we need to send Americans to Mars and beyond”, he told the National Space Council, which was resurrected with a ceremony at the Smithsonian National Air and Space Museum (Virginia).
Going back to plasma technology, it may be the key to getting back to see astronauts on television on another solo beyond the lunar, even just inside a small space base on Mars. “We started thinking about it almost like kids pretending to be astronauts with the same enthusiasm”, tells Vasco Guerra. And adds that the project started by using plasma to decompose carbon dioxide on Earth into applications related to other challenges such as climate change and the growing production of renewable energy. “But as we continued to think about it [creating oxygen on Mars], we began to realize that maybe it was a good idea.”
The PREMiERE project – which intends to use carbon dioxide on Earth as a raw material to make fuel – has led to an interplanetary project. The inspiration came, Vasco Guerra confesses, during a lecture, at the IST, of Dava Newman, then deputy administrator of NASA, about future missions to Mars. “During the lecture, I realized that it might be possible to adapt the knowledge acquired in the PREMiERE project in some way.”
The IPFN team, together with other researchers from IST and the University of Porto, is now developing what Vasco Guerra explains to be the theory, models and simulation of the entire process. And the University of Paris has been doing CO2 decomposition experiments, as well as the Technological University of Eindhoven (The Netherlands), which is also collaborating on the research. They do not know when it will be a reality. But, by then, one might start thinking of putting on Mars solar panels, generators, chambers where the plasmas will be created and the material to collect the oxygen that will be produced.