Mars One

There's a battle of the brains under way online about just how long the first human colonists to set up a new home on Mars will last on the Red Planet. A group of MIT students have challenged the viability of Mars One, a Dutch nonprofit's plan to set up a permanent colony on Mars with hearty volunteer astronauts who get a one-way ticket to both the fourth planet from the sun and history.

While those who sign up and are selected for Mars One's mission fully understand they'll be living out the rest of their days on Mars, presumably they'll be hoping that those days will number into the thousands. However, the MIT students' analysis (PDF) by Sydney Do, Koki Ho, Samuel Schreiner, Andrew Owens and Olivier de Weck estimates that the first fatality on Mars will come at around day 68 of the mission.

"This would be a result of suffocation from too low an oxygen partial pressure within the environment," the paper reads. Titled "An Independent Assessment of the Technical Feasibility of the Mars One Mission Plan," it was presented at the 65th International Astronautical Congress in Toronto earlier this month.

The problem, according to the study, is basically that growing a bunch of crops inside the same structure as living quarters -- as the mission design calls for -- will raise the oxygen in the air to an unsafe level, requiring that extra O2 to be vented outside. However, the MIT students claim that since technology is not available that could exclusively vent oxygen while holding on to the needed levels of nitrogen to ensure enough air pressure for the crew to actually breathe, things start to get really uncomfortable after the imported nitrogen tanks run out on day 66.

Actually, things would already be uncomfortable before lack of oxygen becomes an issue, thanks to the fact that living in a greenhouse would raise humidity levels in the structure to 100 percent, according to the paper.

The MIT paper uses different models for some aspects of the mission than what Mars One actually plans to do, as Mars One doesn't provide many specifics about the technologies it hopes to use. For example, the area for crop growth is four times larger than what is included in the actual mission plan. They rationalize this change by making the case that because "the crop selection will significantly influence the well-being of the crew for the entirety of their lives after reaching Mars, we opt for crop variety over minimizing growth area."

Mars One CEO Bas Landorp responded to the student paper here, saying "There are many problems between today and landing humans on Mars, but oxygen removal is certainly not one of them."

Landorp explains that the technology used in oxygen concentrators commonly found in hospitals and elsewhere can remove oxygen from the atmosphere via a process called "pressure swing adsorption." He says Mars One plans to leave oxygen levels in the habitat at 20 percent, which is comparable to levels seen at high altitude in places like Quito, Ecuador, on Earth.

The MIT paper is also critical of other aspects of the mission, claiming that the number of launches required to get everything staged and set up for the colonists is overly optimistic.

The students say that they based their conclusions on the best available information and will update their findings when more information becomes available. We'll see if that happens now that the existence of oxygen concentrators is apparently on the table. I'm sure the potential future crew members would appreciate an update just as much as the rest of us.

Update as of 8:15 a.m. October 11, 2014: The MIT students have since responded to me via e-mail, and via astatement and aReddit "Ask Me Anything" seeking to clarify that they are aware of the existence of pressure swing adsorption, but note that "no oxygen removal technology has been developed for spaceflight. While oxygen removal devices are regularly used on Earth, the process of developing something that you can purchase off-the-shelf into something that you would operate reliably in an extraterrestrial environment is quite involved. We're not suggesting that this is not possible. Instead, in the paper, we mention that this contradicts the claim (by Mars One) that no new technology developments are required, since space-rating a technology is in and of itself a development effort."

Lead author Sydney Do pointed out that the paper did consider an "idealized oxygen removal system" but their analyses ultimately found that carrying all food from Earth rather than growing it was always cheaper than scenarios that rely on growing food.

Do also tells me that he thinks the most important (and little reported) result of their study was "the fact that the Mars One mission will get more expensive over time (refer to Fig 24 of the paper). This is because every time a crew is launched to Mars: the life support equipment to sustain the crew needs to be launched, plus the spare parts to maintain this equipment, plus the spare parts for all of the equipment that was already placed on the Martian surface on previous missions." The paper recommends on site manufacturing of spare parts as a possible less expensive solution.