“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?