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12 Apr 2023

Neus Sabaté: "The challenge is to generate energy with material from Mars"

The researcher from the Institute of Microelectronics of Barcelona will test a Martian battery based on iron compounds and urine in Hypatia I, a mission of women scientists at the Mars Desert Research Station.

Equipo de Hypatia I


On Earth, she studies how to make sustainable batteries that harness energy from the environment, have minimal components and use abundant materials. But now she is going to Mars to test a battery based on iron compounds very common on the surface of the red planet and human urine. Neus Sabaté, CSIC researcher at the Institute of Microelectronics of Barcelona - National Microelectronics Center, has embarked on Hypatia I, a mission composed of female scientists from different disciplines and ages at the Mars Desert Research Station. This is an analogous facility built by The Mars Society in an environment very similar to the surface of Mars: the Utah desert, in the United States.

For fifteen days, from April 16 to 29, the Hypatia I crew members will carry out their research and outreach activities as if they were in a real human station on the red planet. Therefore, they will be fed mainly on dehydrated food, their drinking water will be rationed, their communications with Earth will be asynchronous and they will have to put on their spacesuits to go outside.

The aim of this adventure is not only to expand scientific knowledge in areas such as energy generation or food production on Mars. Hypatia I also aims to make women scientists visible and inspire vocations, especially among young women and girls.

Neus Sabaté en la presentación de Hypatia IHere on Earth, your research focuses on the development of sustainable batteries. Is the goal of your work on Hypatia I to do the same, but on Mars?

On Mars the question of sustainability will come later. The challenge now is to generate energy with material that is there. The missions before Perseverance, the fourth robot to walk on the surface of Mars, carried solar panels, which generate a certain amount of energy per square centimeter and depend on the availability of sunlight: they don't work at night. In addition, they can end up covered with dust when there are sandstorms, which are very common. Spirit and Opportunity spent ten years circling Mars, so solar panels work, but to provide power to a robot. If we are going to go there ourselves, we will have to generate much more energy to produce oxygen and not freeze to death, because there are extreme temperatures of -100ºC at night.

Does Perseverance also work with solar panels?

Yes, but not only. It has a nuclear thermoelectric generator with a plutonium core that generates heat when it decays. It weighs 50 kilograms and is a much more stationary power source. It is expected to provide power for at least 10 years. It also incorporates lithium batteries that are charged by this generator or by the solar cells and provide energy quickly so that the vehicle can move. In any case, everything we take to a first human exploration of Mars will have to be brought from Earth. That means a lot of weight and volume.  

So, the solution is to generate the energy on Mars?

Yes, I was inspired by the Nüwa project, in which Laia Ribas [another Hypatia crew member] participated and which consists of designing a Martian city for a million inhabitants. The original idea was that everything would run on solar panels, but that is not possible in the case of industry. Ovens and certain industrial processes require very high temperatures and therefore a lot of energy... I don't work with lithium batteries, but with unconventional batteries from paper or biological fluids. With this approach, I studied the chemical compounds detected by Spirit in 2003 and it turns out that Mars is full of materials, like Earth, but with the difference that there are many oxidized compounds and that there is no oxygen in the atmosphere of Mars. The planet is red because there is a lot of iron oxide, so I wondered if it was possible to make a battery using iron chemistry.

Is that what you want to test at Hypatia I?

Yes. On Earth, my research group generates batteries with materials present wherever we go. For example, Juan Pablo Esquivel had a project to generate batteries in Chiapas with coffee waste, which are products that are not used or are burned. Here we would do something similar: go to Mars and see if we can make a battery out of iron or ferric compounds found there. It is what is called zero kilometer manufacturing, although in this case the zero kilometer would be on Mars. If we could do that, we would only have to transport there a casing with electrodes and an empty casing to contain the iron compounds. Therefore, the weight would be very low. Since there is not much water on Mars, and what water there is will have to be recycled and used for living and watering, it occurred to me that the electrolyte, which has to be liquid, could be the urine of the crew members. It is a liquid that is already salty and works very well as an electrolyte. I know this from other research in the group and from my spin off [Fuelium]. I think making such a battery is an original idea that has not been published so far.

What exactly would you do at the Mars Desert Research Station?

The station environment was chosen because of its similarity to Mars: it's isolated, it looks like the images Perseverance sends us, and it's orange because there are iron compounds. In Utah there are stoneware and argillite, which have a small amount of iron, and purer rocks such as hematite, goethite and jarosite. In the lab I have analyzed these rocks and found that, in small amounts, they have compounds that can be exploited electroactively. On the mission I will have to leave the station to look for materials and rocks from the site and, once back, I will analyze their iron content. However, I'm going to get very small amounts of compounds that are not going to be refined, so I'm going to take iron compounds from here to make four batteries to power LEDs that will allow us to germinate soybean sprouts with ultraviolet light. Each day I will collect urine from the crew members, activate the batteries with it and check the power generation. I expect the batteries to run for about 16 hours a day to power the LEDs and at the end of the mission we will be able to eat some fresh bean sprouts, because the rest of our diet will consist of food reconstituted with water.

Will the devices you're thinking about be enough to provide all the energy we'll need to get to the red planet and live there?

They are designed for when we are on Mars. I imagine that at the beginning we will need shovelfuls of materials to be able to extract purer iron compounds to run the batteries. It will be a bit like when in the Wild West the early explorers would get cold at night and grab branches from the trees and build a fire. Anyway, this question I will be able to answer at the end of the mission, when we see what quantities of iron can be collected in the environment. One of our objectives is precisely to know how much energy we could generate with the materials present and how many casings and assembly materials we would have to carry to make that possible.

Are you going to find the same materials on the surface of the Utah desert as on the surface of Mars?

Yes, in the end the universe is made of the same basic components, the same metals, compounds... What varies on Mars are the relative amounts of these materials. Although much remains to be known, the rovers that have explored the surface have confirmed the presence of magnesium and iron, and also that Mars receives quite a few meteorites that have pure iron. The materials look similar; what scientists are now trying to understand is why in the absence of oxygen there is so much oxidation. It seems that chlorates and hyperchlorates also affect and that at some point Mars had water and a breathable atmosphere.

Are you going to develop any outreach activities within the project?

We are going to spread the word about the daily life on a Martian station: the distribution of tasks, the hierarchy, not being able to eat anything fresh, having to go outside in a space suit... It will be very positive for the collective imagination to see women dressed as astronauts and carrying out such high-tech tasks, reminiscent of a space mission.

Why a mission composed only of women?

It is important to generate references. We want young people and girls to have references close to them. They can say "if this lady who was born in Tarragona is doing a super cool mission dressed as an astronaut, why can't I do it too?" Of course you can: you can too... I like this project because when I approach young people and girls I tell them: "if you like space, you don't have to be astronauts; space exploration requires biologists, engineers, mathematicians, physicists and also psychologists and philosophers".

How did you decide to embark on the project?

I'm a very curious person, I like to stick my nose where it doesn't belong, so I found the mission irresistible. We were given 48 hours to decide and it took me less than 24 hours to say yes.

In the simulation, in addition to researching your field, you're going to test how a human team functions under conditions with many constraints. Is it similar to other fieldwork you've done previously?

I've never done field work like this before, so it's a bit of an adventure. It's going to be a challenge to live with people I don't know and to accept that, although I'm used to leading my research and being a group leader, here I'm a bit of the last monkey. I'm one of the crew's engineers and I'm going to be in charge of logistics, managing the water, making sure all the electronics on the base are working properly and doing repairs. It's going to be a humbling job to serve the crew, but I'm really looking forward to a change of role, environment, equipment and different conditions. I'll let you know how it goes when I get back. Maybe it's not so funny.

There is a song by Nacho Vegas called 'No me voy a Marte' (I'm not going to Mars) that talks about the fact that the solution to the ecological and climatic crisis that we have caused on our planet cannot be to escape to another one. Traveling to Mars is undoubtedly a fascinating challenge, but will it be sustainable for our planet and Mars itself?

I don't know what sustainable means in this context. As a scientist, I see traveling to Mars as a scientific and technological challenge. A few years ago when the LHC was inaugurated, people said, "this has been worth many millions, is it worth it?" Of course it's worth it because it's nice that mankind spends millions, not on weapons, but on discovering fundamental particles. This is something similar. There will be agencies that will have military or exploitation interests in the neighboring planet, but on a scientific and technological level traveling and surviving there has an undeniable attraction because it is very easy to orient world research towards a challenge like this. It is a challenge that unites us as a planet. In addition, it will allow us to develop technologies that will later be applicable on Earth. Technologies for living with little water and no oxygen could be good for our future here as well. For example, solar panels were originally developed to power satellites, gadgets that flew around, and it didn't occur to anyone at the time that they could become a source of renewable energy on Earth.

What about the ethical aspect of colonizing another planet?

Yes, you have to consider what happens if we as humans go to another planet that is not ours and how we should approach it. Earlier I was talking about the colonizers of America. We already know that they were not respectful of the original life on the continent. Maybe we should learn. For the moment, it seems that if Martians exist they will be microscopic and in bacterial format, so the debate on how to approach the planet is open. The song by Nacho Vegas is good because it invites us to start up the whole field of philosophy of science and humanity.

Images by Mercè Fernández and Pau Fabregat

Interview by Eduardo Actis and Irene Lapuerta (CSIC Cultura Científica)