Mars colonization faces several severe obstacles: atmospheric pressure far below the Armstrong limit (610 pascals average versus the 6,250 pascals humans require without pressure suits), an atmosphere of 95% carbon dioxide, surface radiation 2.5 times higher than at the International Space Station, toxic perchlorate-laden soil, and temperatures that average between 186 and 268 Kelvin. Global dust storms can cover the entire planet for weeks, cutting power and communications.
How long does it take to travel to Mars?
A Hohmann transfer orbit from Earth to Mars takes approximately nine months. Modified trajectories can cut that to four to seven months at higher fuel cost. Advanced propulsion concepts such as nuclear rockets could reduce the journey to about two weeks, and a Variable Specific Impulse Magnetoplasma Rocket could potentially achieve a trip of around forty days.
How much radiation would Mars colonists face?
The Mars Radiation Environment Experiment on the Mars Odyssey spacecraft measured radiation levels in Martian orbit at 2.5 times those at the International Space Station. The average daily dose was about 220 microgray, equivalent to roughly 0.08 gray per year. A three-year exposure at those levels would exceed NASA's current safety limits, and a round-trip mission could raise a male astronaut's cancer mortality risk by between 1% and 19%.
What is the minimum number of people needed for a Mars colony?
Jean-Marc Salotti used mathematical modeling to conclude that the minimum viable Mars colony requires 110 people. Other studies focused on genetic sustainability have suggested ranges from 198 to as high as 10,000. More recent research incorporates institutional needs, such as having enough colonists to assemble a twelve-person jury where no juror knows the defendant personally.
Who are the main advocates for colonizing Mars?
SpaceX, founded by Elon Musk, has declared Mars colonization its long-term goal and uses the term "Occupy Mars" to describe its ambitions. Robert Zubrin, author of The Case for Mars (1996), has advocated for Mars colonization for decades through the Mars Society. Buzz Aldrin presented a formal colonization plan to NASA in August 2015, calling for astronauts on ten-year tours of duty to establish a colony before 2040.
Is the colonization of Mars legal under international law?
The 1967 United Nations Outer Space Treaty states that no country may claim sovereignty over space or its celestial bodies, and many of its articles directly conflict with the legal concept of colonization. The term "colonization" is largely avoided by public space agencies for this reason, with "settlement" preferred instead. How the treaty applies to private companies rather than nation-states remains an unresolved question.