How humans will live on the Moon

16^th Novem­ber 2022. The huge SLS launch­er lifts off from Launch Com­plex 39 at the Kennedy Space Cen­tre in Flori­da with the mis­sion to send the new Ori­on space­craft, devel­oped by the US Space Agency (hab­it­able mod­ule) and the Euro­pean Space Agency (ser­vice mod­ule), around the Moon.

This mis­sion, named Artemis I, was a great suc­cess but was only the first step in prepar­ing for the return of humans to the Moon in 2024 (a manned Ori­on fly­by this time) and 2025 (when a man and a woman should set foot on the Moon again).

But unlike the Apol­lo pro­gramme of the 1970s, this new manned return to the Moon is a long-term pro­gramme. Indeed, plans have already been made to place a lunar space sta­tion sim­i­lar to the Inter­na­tion­al Space Sta­tion into orbit (sev­er­al mod­ules have already been built) and to grad­u­al­ly set up a lunar base on the ground, which will ini­tial­ly be vis­it­ed by astro­nauts on an ad hoc basis, but whose ulti­mate objec­tive is to be per­ma­nent­ly inhabited.

To imple­ment this ambi­tious pro­gramme, it is nec­es­sary to adapt to the hos­tile envi­ron­ment of the Moon and to devel­op facil­i­ties capa­ble of main­tain­ing a hab­it­able zone in what is one of the most extreme envi­ron­ments that humans have ever known. Let’s talk today about the tech­no­log­i­cal and indus­tri­al chal­lenges that lie ahead on the Moon in the com­ing decades.

To main­tain a sta­ble and safe habi­tat, you have to start by analysing the envi­ron­ment in which you want to set­tle and know­ing the con­straints it will place on build­ings and peo­ple. As the Moon is small­er than the Earth, its mass is low­er. The Moon’s grav­i­ty is six times weak­er than Earth­’s: all the cal­cu­la­tions for archi­tec­ture, struc­tures and mate­r­i­al resis­tance must there­fore be reviewed in depth.

In addi­tion, the Moon has a very slow rota­tion. There, a day lasts about two Earth weeks, as does the night. And with­out an atmos­phere to homogenise the tem­per­a­tures between the light and dark sides, tem­per­a­tures vary from 120°C dur­ing the day to ‑250°C at night! Not to men­tion that on the Moon, mete­oroids arrive intact and at full speed to the ground. Final­ly, we must take into account the per­ma­nent irra­di­a­tion of the lunar sur­face by cos­mic rays, a stream of par­ti­cles whose exces­sive dose can cause burns, steril­i­ty or the appear­ance of cancers.

Sev­er­al options have been stud­ied to coun­ter­act these effects. One option is to use ancient lava tun­nels just below the Moon’s sur­face to build a pro­tect­ed envi­ron­ment, shield­ed from exter­nal con­di­tions (see illus­tra­tion below). How­ev­er, the Artemis pro­gramme is now plan­ning to set­tle near the lunar south pole, where there is cur­rent­ly no evi­dence of these vast under­ground tunnels.

The lunar base projects envis­age sur­face activ­i­ties, which there­fore need to take into account these par­tic­u­lar lunar con­di­tions. In 2016, the Euro­pean Space Agency pre­sent­ed its “Moon vil­lage” con­cept. The idea was to launch inflat­able mod­ules onto the sur­face, which robots would cov­er with a thick lay­er of con­crete devel­oped on site from lunar regolith.

Inflat­able struc­tures are not new to the space sec­tor. An inflat­able mod­ule called BEAM (Bigelow Expand­able Activ­i­ty Mod­ule) was even test­ed and installed on the Inter­na­tion­al Space Sta­tion in 2016. The French start-up Spar­tan Space is devel­op­ing an inflat­able and mobile habi­tat solu­tion that can be used as a tem­po­rary base camp dur­ing expe­di­tions far from the main base.

Europe’s lunar vil­lage also relies on the mas­sive use of 3D print­ing robots that can har­vest lunar regolith, mix it with var­i­ous glues and then spray the result­ing paste onto inflat­able mod­ules to build the pro­tec­tive lay­er that will keep astro­nauts safe.

Because the robot­ics indus­try will have a very impor­tant role to play on the Moon. In a place where even the small­est step is a dead­ly risk, it is like­ly that robots will be used for many sur­face activ­i­ties. But there are still many prob­lems to be solved before we can deploy flotil­las of agile and effi­cient lunar robots.

Between the elec­tro­sta­t­ic and high­ly abra­sive lunar dust that gets into all the gears and sticks to all the sur­faces, and the impos­si­bil­i­ty of using con­ven­tion­al lubri­cants that dry out or evap­o­rate in the vac­u­um of space, there is still a lot of progress to be made and inno­va­tions to be found.

The robot­ics indus­try will have a very impor­tant role to play on the Moon.

Anoth­er fun­da­men­tal point is the pow­er sup­ply. The advan­tage for the Artemis project is that the Sun is always present, low on the hori­zon, so that large quan­ti­ties of solar pan­els can be deployed on the exposed sides of craters. But as the base grows, it will cer­tain­ly need to be sup­ple­ment­ed by small, com­pact nuclear pow­er plants. In June 2022, NASA and the Depart­ment of Ener­gy (DoE) select­ed just three pro­pos­als for nuclear fis­sion pow­er sys­tems: the lat­ter could be ready to launch by the end of the decade for a demon­stra­tion on the Moon.

Min­ing, for exam­ple, which is one of the rea­sons for humans return­ing to the Moon. The main resource is water, of course, which is found in large quan­ti­ties in the form of ice at the bot­tom of craters in the lunar poles. This water will be used for food and local agri­cul­ture, as well as to make fuel (in the form of oxy­gen and liq­uid hydro­gen) for the rock­ets that will take off from the Moon.

But the lunar soil is poten­tial­ly rich in oth­er resources of imme­di­ate inter­est to the min­ing indus­try, such as oxy­gen and sil­i­con, which are present in large quan­ti­ties, but also var­i­ous met­als such as alu­mini­um and iron. In the longer term, the lunar min­ing indus­try could be inter­est­ed in Helium‑3, which is need­ed for future ther­monu­clear fusion reac­tor technologies.

If humans are to remain on our satel­lite for long peri­ods of time, oth­er tech­nolo­gies and indus­tries will have to be devel­oped to adapt to the lunar envi­ron­ment. Med­i­cine, agri­cul­ture, and biotech­nol­o­gy will be cru­cial for the future, but all this will come lat­er, once it has been proven that human pres­ence in this alien envi­ron­ment is real­ly possible.

Then per­haps one last indus­try will devel­op, a heavy­weight that accounts for near­ly 7% of the world’s GDP: tourism. Whether it is a fly­over, in orbit or on the ground, for a short or long peri­od, the Moon could become the unmiss­able des­ti­na­tion of the next century…