In mid-2012, the Mars One program was announced, aiming to build the first human settlement on the surface of Mars. Following a series of precursor missions to develop and deploy key technologies, the first crewed mission would depart Earth in 2024, sending four people on a one-way journey to the surface of Mars.
A first simulation of the baseline Mars One habitat indicated that with no ISRU-derived resources, the first crew fatality would occur approximately 68 days into the mission. This would be a result of suffocation from too low an oxygen partial pressure within the environment, as depicted in Figure 8.
At the same time, the habitat would be put into a state of high fire risk due to the oxygen molar fraction exceeding the 30% safety threshold, as indicated in Figure 9.
Further investigation revealed that this non-intuitive result is primarily caused by the plants producing excessive oxygen, increasing oxygen partial pressure to outside their partial pressure control box, and causing the pressure control assemblies to vent air. Because the PCAs are not able to selectively vent a gas species, the oxygen molar fraction remains the same after venting, while the total atmospheric pressure reduces. Nitrogen is then selectively introduced into the environment to bring down the oxygen molar fraction. Over many cycles of air venting and nitrogen being introduced for oxygen molar fraction control, the nitrogen tank empties on day 66 of the mission (see Figure 10).
An independent assessment of the technical feasibility of the Mars One mission plan (PDF)
IAC-14-A5.2.7
An independent assessment of the technical feasibility of
the Mars One mission plan
Sydney Do
Koki Ho, Samuel Schreiner, Andrew Owens, Olivier de Weck
MIT
http://web.mit.edu/sydneydo/Public/Mars%20One%20Feasibility%20Analysis%20IAC14.pdf
MIT students predict Mars One colonists will suffocate in 68 days
by Ryan Whitwam
GEEKNEWSLETTER
http://www.geek.com/science/mit-students-predict-mars-one-colonists-will-suffocate-in-68-days-1606559/
No one ever said going to Mars on a shoestring budget was likely to be completely safe, but a new analysis of the plans set forth by Mars One makes the prospect of this televised mission seem much more bleak. A group of engineering grad students from MIT have put together a 35-page analysis of Mars One’s plans and found it would take about 68 days on the Red Planet for the first fatalities. That’s not super-encouraging.
Mars One plans to send a communication station, rover, and habitat modules to Mars ahead of the human adventurers, with the understanding they will spend the remainder of their lives on the planet. People will be transported every two years in groups of four until there’s a thriving colony on the Red Planet. Mars One plans to have the colonists grow their own food and use the oxygen produced to maintain a breathable atmosphere. However, this is the most significant issue the MIT students identified.
The Mars One plan calls for the habitats to be within the same space as the crops are grown. This saves weight on the trip and simplifies the design of the habitats. At about 68 days, the first wheat crop will reach maturity and the level of oxygen will spike. To avoid a huge fire hazard, the oxygen will need to be vented, but there is not yet a reliable way to preferentially vent oxygen without also venting the nitrogen used to maintain pressure. Thus, the colony will run out of nitrogen almost immediately. The end result, says the paper, is suffocation due to low air pressure. Well, that or the habitat explodes and the survivors suffocate outside. On a less fatal note, the students also point out the humidity inside the habitat would likely hover around 100% as the crops reach maturity.
Mars One
As a fix, the paper suggests building a separate structure for growing food and siphoning off only the oxygen needed for breathable air for the habitats. This would be an expensive change, though. It may actually be cheaper to ship food to Mars on a regular basis–that’s about 15 deliveries for each four person crew at a cost of $4.5 billion. Considering the entire budget for the Mars One mission is $6 billion, that’s probably not happening.
The CEO of Mars One has responded to the paper, claiming that it will be possible to develop the necessary venting technology using medical oxygen concentrators by the time the manned mission launches in 2022. He also says the payloads will not be as heavy as estimated in the paper. He refused to offer any specifics, though.
人は火星で68日間の命、米研究
by Fabienne Faur
AFP
http://www.afpbb.com/articles/-/3028927
火星への移住を計画している人に「待った」がかかるような研究報告書がこのたび発表された──米マサチューセッツ工科大学（Massachusetts Institute of Technology、MIT）の研究者らが発表した報告書によると、現状では火星への移住後68日以内に「移住者らの死」が始まる可能性があるという。
報告書で研究者らは、火星のコロニーでは開始から約2か月後に酸素レベルに問題が発生するとしており、永住のためには新たな技術が必要と指摘している。
今回の研究では、2024年からの開始が予定されている、火星への移住計画を進める非営利企業「マーズ・ワン（Mars One）」のデータが用いられた。
最初の移住計画に参加するメンバー24人は、応募者20万人から選抜した約1000人の候補者のなかから選ばれる。
しかし、火星の諸条件と人類の技術では、少なくとも現時点での火星移住は難しいかもしれない。
移住に必要となる酸素、食糧、技術について解析した35ページの報告書には、「開始から68日あたりで最初のグループから死者が出るだろう」と記されている。
コストの面では交換部品輸送が大きな課題となり、移住計画では少なくとも450億ドル（約4兆8000億円）の費用が必要となると推定されている。
マーズ・ワンの共同創設者で最高経営責任者、バス・ランスドルプ（Bas Lansdorp）氏も、この輸送をめぐる問題を認めている。しかし、今回の研究では不完全なデータが使用されており、「火星に行く技術がまだ準備できていないというのには同意できない」とAFPの取材に語った。
同プロジェクトには多くの人が懐疑的な声を上げているが、1999年にノーベル物理学賞を受賞したオランダのヘーラルト・トホーフト（Gerard ‘t Hooft）氏は支持を表明している。