Apr 16 2015

Mission to Mars

Mars is an interesting place. The more we study the surface of the planet with our various robot labs, the more interesting it becomes. This is one of the reasons that it is very enticing to send people to Mars, but there is debate about the feasibility of any mission to Mars over the next few decades.

Life on Mars

Recently the Curiosity rover found evidence that suggests there might be briny liquid water just under the surface of Mars. When the temperature and humidity are just right, salts in the Martian soil could absorb moisture from the air creating a subsurface briny liquid water. This water would then evaporate again when temperatures rise during the day, creating a water cycle.

This would be a harsh environment for life, perhaps not compatible with life as we know it, but extremophiles have surprised us before. It is perhaps more likely that deeper down in the Martian dirt there is more permanent liquid water and more protection from cosmic rays, meaning that life could endure in slightly less extreme conditions.

There are also geological features that suggest recent flowing something, perhaps water bubbling up temporarily from below the ground, and flowing briefly before it evaporates in the thin Martian atmosphere.

The possibility of finding life on Mars is one of the most exciting scientific questions of our time. Even evidence of past life would be amazing. Our best chance of finding this evidence might be through more and more sophisticated rovers. Having actual scientists on Mars, however, wouldn’t hurt.

Mars OneĀ 

A private group (Mars One) has received some attention recently by announcing its plans to send permanent settlers to Mars by the 2020s. We recently interviewed Chris Patil, one of the final 100 contestants for the Mars One missions, on the SGU. He was enthusiastic but realistic. The topic also came up recently at NECSS. Bill Nye, CEO of the Planetary Society and an exuberant proponent of space exploration and popularizer of science, was highly skeptical of the Mars One approach.

Mars One intends to raise 4 billion dollars, and claims that we have the current technology to send people to Mars and establish a permanent settlement. We don’t have the actual applications necessary – we will have to create the combinations of current technology that will be necessary.

Nye feels that there is no way to pull off this mission with 4 billion dollars. The challenges are just too great. Let me review some of them:

The trip to Mars will be long, at least several months, during which time the crew will have to survive in a cramped capsule. The capsule will have to be shielded from cosmic rays. The crew will need enough space to exercise, and to store sufficient food and water. Unlike the ISS, there will be no resupply missions.

Once they get to Mars they will have to land. As Nye pointed out – the atmosphere is too thin to be of any help, but too thick to ignore. We have landed equipment on Mars, but not people. There is more gravity than the moon, and the wispy atmosphere can still kick up killer dust storms. It is not thick enough for parachutes to be sufficient, however. We will need to develop a landing system optimized for Mars. This does not seem like a deal-killer, but is just one more challenge.

Once on Mars they will find a distinct lack of oxygen, water, and protein. There is also a lack of a magnetic field, which means there is an excess of cosmic rays. What this means is that any colony on Mars, in order to be self-sustaining, will need the ability to extract oxygen and water from the environment, and to grow sufficient food. They will need a habitat that will protect them from the cosmic rays. To make all this work they will also need a reliable source of energy.

While all of this is not impossible, it will take a substantial infrastructure. This gives us a bit of a chicken and egg problem. Do we build some or all of the infrastructure with robots then send people, or do we send people to build the infrastructure? Likely there will be some combination – it would be nice to have at least lots of supplies, a source of energy, and some prefab components waiting for the first Martian settlers.

Patil made the point that it will always be easier to go to Mars (or do anything huge) in the future, but at some point we just have to bite the bullet.

Nye and others feel that other Mars missions would be a better idea. First lets just get people into Mars orbit. From there they could control rovers in real time, do a few weeks or even months of science, then return home. We could also land people on Mars for a brief stay, and then return them home. While doing these temporary missions we will be developing the technology and experience that will enable a future permanent settlement on Mars.

There are also those who argue that sending people to Mars at all is a waste of resources. For the same money we could send many robotic missions. It’s dangerous and expensive to send people to space. Robots don’t need things like food or air, and they can tolerate the radiation.

Conclusion

I tend to agree mostly with Bill Nye. I do think it is worthwhile to send people into space, and to eventually colonize the Moon, Mars, and elsewhere in the solar system.

But we need to recognize that colonizing any place off the Earth is really difficult, and will take tremendous resources. I don’t think we need to wait until robots have built a luxury infrastructure for humans to stroll into, but neither should our first human mission to Mars have the goal of a permanent settlement. Let’s slowly build our infrastructure, for Earth orbit, the Earth-Moon system, and eventually Mars and elsewhere. The effort should be international, will collaboration between private and public institutions.

Ultimately I think that Mars One is a useful idea. At the very least it is an interesting thought experiment, and could increase enthusiasm for space exploration and science in general. As currently planned, however, it will also almost certainly fail. Its timeline is way too optimistic, the task is harder than imagined, and the project will need far greater resources than planned. Mars One may evolve into a project that can succeed, but not as currently conceived.

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