“Mars is the new American frontier”

Where can we real­is­ti­cal­ly envis­age going for space explo­ration missions?

Fran­cis Rocard. If we con­sid­er manned or resource exploita­tion mis­sions, pos­si­ble des­ti­na­tions are the Moon, Venus, Mars or aster­oids. Today, explo­ration projects are main­ly con­cerned with Mars. Let me explain. With the Apol­lo mis­sions, the Amer­i­cans went to the Moon. Kennedy won the gam­ble he had tak­en to get there before the end of the decade and ahead of the Rus­sians. At the time, it was imag­ined that there would be a new El dora­do in space after tele­coms with micro­grav­i­ty to pro­duce mate­ri­als or med­i­cines, and that all this would attract pri­vate invest­ment. Fifty years lat­er, it must be said that that part was a mis­ap­pre­hen­sion. In the end, there was no pri­vate invest­ment as had been expect­ed, and space explo­ration was ulti­mate­ly fund­ed by pub­lic resources alone. Fol­low­ing that, the Unit­ed States focused on low Earth orbit and built the Inter­na­tion­al Space Sta­tion (ISS). But it is now becom­ing frag­ile as it requires a lot of main­te­nance and is expect­ed to be shut down by 2028–2030. To main­tain its lead­er­ship in space, the US needs to move on. So, the next step will almost cer­tain­ly be Mars!

Why Mars?

It’s not for sci­en­tif­ic rea­sons or to find traces of life because that is already under­way with the Per­se­ver­ance rover and the sam­ples it will bring back to Earth in sev­er­al years for analy­sis. More­over, when Kennedy launched the project to go to the Moon, the ques­tion of a sci­en­tif­ic return was not even on the cards! Nor was it to exploit resources. After all, there is no finan­cial return to be expect­ed from those activ­i­ties. The only inter­est­ing resources on Mars are those that will be used for the mis­sion. When asked by jour­nal­ists why he want­ed to climb Ever­est, the moun­taineer George Mal­lo­ry replied: “because it’s there”. The same is true of Mars. After the Moon and low Earth orbit, it is the most inspir­ing goal. More­over, there is a real con­sen­sus between the White House, Con­gress and NASA on this com­mon goal of pur­su­ing human space­flight and main­tain­ing the Amer­i­can lead in this field. In 2010, Pres­i­dent Barack Oba­ma can­celled the Con­stel­la­tion pro­gramme, which aimed to send astro­nauts to the Moon on long-dura­tion mis­sions. How­ev­er, he did not can­cel the long-term vision of send­ing astro­nauts to Mars. It is said that a leader does not com­pare him­self to oth­ers, that he must take risks and move for­ward and that is what the US is doing. Mars is the new Amer­i­can frontier!

The project is far too heavy and too expen­sive to do every­thing in par­al­lel as was done for the Moon, where all the dif­fer­ent com­po­nents were car­ried out at once.

How will we get to Mars?

In sev­er­al stages. The project is far too heavy and too expen­sive to do every­thing in par­al­lel as was done for the Moon, where all the dif­fer­ent com­po­nents were car­ried out at once: the launch­er, the lunar mod­ule, the Apol­lo cap­sule, the rover, etc. This mod­el is absolute­ly impos­si­ble for Mars. To do that, you would need to mul­ti­ply NASA’s annu­al bud­get – cur­rent­ly ~$22 bil­lion – by at least 4 times, not count­ing the bud­gets of the Depart­ment of Defense and oth­er agen­cies involved. So, it will have to do be done sequen­tial­ly. This plan makes it pos­si­ble to extend the dura­tion, to spread out expen­di­ture over time and to devel­op the tech­nolo­gies, tools and vehi­cles which, when put togeth­er, will make it pos­si­ble to reach Mars – a par­tic­u­lar­ly com­plex des­ti­na­tion, to say the least.

Strate­gic and geo­graph­i­cal stages have been defined to move from low orbit to the sur­face of Mars. The choice was made to start from lunar orbit (around the moon) where the Lunar Orbital Plat­form Gate­way (LOP‑G), a space sta­tion, a sort of small ISS, will be built. The Pow­er Propul­sion Ele­ment (PPE), a type of space-tug, will trans­fer the habi­ta­tion mod­ules from Earth orbit to the Moon’s orbit where they will be assem­bled. This tug pre­fig­ures the one that will be used to trans­port the mod­ules to Mars lat­er on.

The main inno­va­tion in this scheme is the auton­o­my required for this sta­tion, which will have to be main­tained at 380,000 km from Earth. The LOP‑G will make it pos­si­ble to see how to sat­is­fy resource require­ments, in par­tic­u­lar water that will need to be extract­ed from the cold craters of the South Pole, and to study the pos­si­bil­i­ty of man­u­fac­tur­ing pro­pel­lants. There are many prob­lems to be solved for the pro­duc­tion of oxy­gen or hydro­gen, espe­cial­ly for liq­uid hydro­gen, which would have to be stored in large tanks to be able to refu­el when necessary.

The LOP‑G will be like a fill­ing sta­tion where you come to fill up with water or fuel before going to Mars. Sim­i­lar­ly, to find out if it is pos­si­ble to pro­duce methane, we need to go to the cold craters on the Moon to see if there is any car­bon, quan­ti­fy it, find out what tech­nolo­gies are avail­able and under what con­di­tions it can be extract­ed, because in these craters the tem­per­a­ture drops to ‑200°C! The Mox­ie demon­stra­tor on board the Per­se­ver­ance rover has suc­ceed­ed in pro­duc­ing a few grams of oxy­gen from the CO₂ in the Mar­t­ian atmos­phere, but to go to Mars, live there and return, tonnes of oxy­gen and methane will have to be produced.

So, the Moon is the prepa­ra­tion and rehearsal site for Mars?

This stage of the LOP‑G will allow us to car­ry out ‘Proof of Con­cepts’, with­out which we will nev­er know if it is pos­si­ble to go to Mars. That being said, it must only be a step in the process. We must avoid get­ting stuck on the Moon. We will have set up bases and send astro­nauts, but the risk is that the lunar phase will last longer than expect­ed, espe­cial­ly as the Chi­nese will also be there and the Amer­i­cans will want to occu­py the ground. Expect­ed to last about ten years, this phase could last up to two or even three decades. But while it lasts, it will con­sume a big chunk of NASA’s bud­get, bear­ing in mind that each SLS launch costs about $1 bil­lion. The ques­tion is, when will the switch to Mars take place?