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…