π Space
Conquering Mars: realistic venture or a fantasy?

“It’s as much about going to Mars as it is about coming back!”

Sophy Caulier, Independant journalist
On September 8th, 2021 |
4 mins reading time
“It’s as much about going to Mars as it is about coming back!”
Gerald Sanders
Gerald Sanders
In-situ resource utilisation (ISRU) system capability manager at NASA
Key takeaways
  • It takes three days to get to or from the Moon and the journey to Mars takes between six and eight months.
  • For long-duration space exploration missions, astronauts will have to find or produce enough resources to sustain themselves.
  • The In Situ Resource Utilisation (ISRU) programme is developing techniques to locate, extract, process and exploit local resources.
  • Today, developments are focusing on methane or hydrogen fuel production.
  • There are four main challenges: knowing what resources are available; how to exploit them; controlling the environment; and ensuring reliability of the project.

To reach the Moon, then Mars and stay there for long peri­ods of time, astro­nauts will need to either take resources with them or have them trans­port­ed to them from Earth or lunar orbit. Nev­er­the­less, how­ev­er, they will still need to be able to process resources found on the ground to meet their needs. How will these resources be extract­ed and processed? In Situ Resource Util­i­sa­tion (ISRU) pro­grammes are designed to find ways to best answer the question.

Why will we need to exploit resources in space, and how can it be done?

Ger­ald Sanders. For long-dura­tion space explo­ration mis­sions to the Moon or Mars, astro­nauts will need to find or pro­duce the resources they need to breathe, shel­ter, or feed them­selves, trav­el and con­duct their mis­sions. As such, being able to use ‘local’ resources such as water, car­bon or oxy­gen dur­ing these mis­sions will reduce the mass to be launched from Earth – a fac­tor that has a direct impact on the cost of mis­sions. For every kilo­gram that lands on Mars, between 7.5 and 11 kilo­grams will have to be launched into Earth orbit. And to reach Mars, mil­lions of tonnes of pro­pel­lants, i.e. rock­et fuel, will be need­ed, equiv­a­lent to the pay­load of sev­er­al super-launch­ers. More­over, fuel will also have to be pro­duced on site if the astro­nauts are going to have a good chance of return­ing to Earth. It’s not just about going to Mars, it’s also about com­ing back.

The aim of the In-Situ Resource Util­i­sa­tion (ISRU) pro­gramme at NASA is to devel­op tech­niques for locat­ing, extract­ing, pro­cess­ing and exploit­ing local resources, ores and chem­i­cal com­po­nents required for explo­ration mis­sions. In con­crete terms, we will need to have means of loco­mo­tion, extrac­tion infra­struc­tures, ener­gy pro­duc­tion, pro­cess­ing and stor­age of prod­ucts, man­u­fac­ture of machines and tools, com­mu­ni­ca­tion, main­te­nance, etc., just as we do on Earth but in extreme con­di­tions of tem­per­a­ture, dust, and absence of atmos­phere. That being said, the ques­tion of pro­duc­ing in space is not a new idea. I read a tech­ni­cal arti­cle on how to pro­duce oxy­gen from lunar soil, which was writ­ten by an engi­neer in 1961, i.e. before man had even been to the Moon!

What resources could poten­tial­ly be used?

First­ly, nat­ur­al resources: water, oxy­gen, hydro­gen, nitro­gen, sil­i­con, car­bon or rocks, par­tic­u­lar­ly regolith on the Moon or Mars. All these resources will be used for life sup­port of astro­nauts, for the pro­duc­tion of fuels, pho­to­volta­ic cells or con­struc­tion mate­ri­als, among oth­ers. At present, devel­op­ments are focused on the pro­duc­tion of oxy­gen and fuel, par­tic­u­lar­ly methane or hydro­gen. But resources also include all the waste that has to be destroyed or trans­formed, and spare parts. You have to be able to repair a sys­tem with­out wait­ing for the next deliv­ery to bring back the miss­ing part. The prob­lems to be solved are very dif­fer­ent depend­ing on whether the mis­sion takes place on the Moon or on Mars. It takes three days to get to or from the Moon, where­as the trip to Mars takes between six and eight months, and the opti­mal launch win­dow from Earth, only occurs every 26 months – when the two plan­ets are closest.

What are the main challenges?

There are four. The first is to under­stand what resources are avail­able local­ly and to know them well. Thanks to the mis­sions that have been car­ried out so far, we already have a good knowl­edge base of the resources on the Moon, and we are col­lect­ing ever more infor­ma­tion about those on Mars. Then, there is the chal­lenge of exploit­ing these resources. We have known how to mine on Earth for cen­turies, but what equip­ment will enable us to mine on Mars and process the ores? How will we pow­er them? How will they be main­tained? These are all ques­tions that we need to answer now.

This brings us to the third chal­lenge, that of the envi­ron­ment. There is a lot of radi­a­tion on Mars and less grav­i­ty, so we have to rethink how to do things. We are study­ing in the Arc­tic, in the desert or at the bot­tom of the ocean to find rel­a­tive­ly sim­i­lar con­di­tions, but they are still very dif­fer­ent from what we will find on Mars. The fourth chal­lenge is reli­a­bil­i­ty, which must be total for manned space flight. When they come back to Earth, astro­nauts must be sure that they have the right fuel, that they land in the right place etc. In short, we must define the best strat­e­gy. On top of that, there is a fifth chal­lenge, which is more polit­i­cal than tech­ni­cal: def­i­n­i­tion of a space treaty and adher­ence to it by all the stake­hold­ers involved.

Will tech­no­log­i­cal progress enable us to meet these challenges?

We are build­ing on the tech­nolo­gies we know on Earth, and we are try­ing to turn the char­ac­ter­is­tics of the space envi­ron­ment to our advan­tage. For exam­ple, we could exploit the vac­u­um on the Moon to con­duct exper­i­ments that are dif­fi­cult to do on Earth. We are not look­ing for per­fec­tion, but for effi­cien­cy and a good return on invest­ment. We are also look­ing for lessons that can be used on Earth. How to pro­duce fuel, elim­i­nate main­te­nance or design lighter equip­ment could help reduce our car­bon footprint.

Why not just send robots, as this would reduce the need for water and oxy­gen? Our approach is not humans ver­sus robots, but both togeth­er. While robots are extreme­ly use­ful, there are things humans can do and under­stand that robots can­not.  The first SpaceX tourist flight to the Moon will car­ry a Japan­ese col­lec­tor and eight mem­bers of the pub­lic, includ­ing artists, who will report on their expe­ri­ence. I’ve talked to astro­nauts and geol­o­gists from the Apol­lo mis­sions. They have an imme­di­ate under­stand­ing of the geol­o­gy of what they see, they under­stand instant­ly what has hap­pened, they know where to take sam­ples. Where­as a robot needs a long learn­ing curve to under­stand. Not to men­tion the laten­cy of com­mu­ni­ca­tions between Earth and Mars, which makes remote con­trol difficult.