Moving Humanity Towards Life Away From Earth — What 'Away' Really Costs, and What It Gives

"Away" sounds simple.

In practice it is a trade. An honest trade deserves both columns.

What away costs

The body pays first.

On Mars you weigh about 38% of what you weigh on Earth.

Months of weightlessness change the body. Astronauts come home with changes to their eyes, among other effects that are still being studied.

NASA's Twins Study compared astronaut Scott Kelly, after nearly a year in orbit, with his identical twin on the ground. Most of the changes, including about 91% of the gene-expression changes, returned to baseline back on Earth.

A few did not: some gene expression, DNA damage, eye changes, and slower, less accurate performance on cognitive tests that lasted six months after landing (Garrett-Bakelman et al., Science, 2019).

Is 38% gravity enough to protect a body over a lifetime? It's one of the biggest open questions in the field.

We don't know yet.

Radiation is the second cost.

During Curiosity's cruise to Mars, its RAD instrument measured the radiation inside the spacecraft. Scaled to the shortest round trip possible with today's propulsion and similar shielding, the dose equivalent came to about 0.66 sievert (Zeitlin et al., Science, 2013).

That is roughly comparable to NASA's current career limit of 600 millisieverts. Even before any time on the surface. (The two numbers are calculated differently: the limit is an "effective dose," so the comparison is approximate.)

Living there means shielding. Regolith walls, buried habitats, careful scheduling.

Distance is the third cost, and the most human.

Messages take minutes each way, up to about 22 minutes at the worst point of a mission.

You cannot call your mother. You can write to her.

In Mars-500, a 520-day simulated mission with six male volunteers, the crew grew steadily more sedentary. The researchers flagged monotony and boredom as risks to plan for.

Individual problems with sleep or mood tended to appear early and persist. Friction ran mostly between the crew and mission control, not among crewmates (Basner et al., PNAS, 2013; Basner et al., PLOS ONE, 2014).

What away gives

A second home for everything we are. (Our argument, not a finding.) A civilization on one planet shares one fate. A civilization on two has a backup of its knowledge, its people and its future.

A forcing function for better tools.

Between 2021 and 2023, NASA's MOXIE experiment made oxygen from the Martian air 16 times. About 122 grams in all, roughly what a small dog breathes in 10 hours.

It was a small demonstration, and a real one. Supplying a settlement's air would take systems far larger.

Closing water loops. Growing food in sealed systems. These are hard problems.

Hope, not a promise: answers built for Mars could feed back into how we handle drought, energy and resilience on Earth.

A new kind of people.

Vision, not a forecast. If children are ever born on Mars, they would be the first humans whose home sky is not ours.

There are no human data at all on pregnancy or child development in 38% gravity. Whether it can be done safely is unknown. That question comes first.

If it can be answered, imagine 2120:

• a Martian culture with its own accent, holidays and local government
• habitats designed around mental health, with daylight-tuned lighting and real privacy
• crews chosen to work well together
• families on two worlds who keep in touch through long letters instead of live calls

That is a picture, not a plan with a date. We offer it so you can see what the trade is for.

The honest bottom line

Away costs bone, dose and distance.

It may give survival, invention and a new branch of the human story.

MarsFirst exists because we think the trade is worth making carefully, with the science in hand, before anyone packs a bag.

Why push toward the hardest questions at all? Start at the Galactic Center.

Mention of NASA, ESA or any agency does not imply endorsement.

Sources

1. Garrett-Bakelman F.E. et al., "The NASA Twins Study: A multidimensional analysis of a year-long human spaceflight," Science 364, 2019. doi:10.1126/science.aau8650
2. NASA, "NASA's Twins Study Results Published in Science Journal." https://www.nasa.gov/humans-in-space/nasas-twins-study-results-published-in-science-journal/
3. Zeitlin C. et al., "Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory," Science 340, 1080–1084, 2013. doi:10.1126/science.1235989
4. NASA-STD-3001 Vol. 1 Rev C, [V1 4030]: career effective dose limit of 600 mSv. https://www.nasa.gov/reference/4-0-human-performance/
5. NASA, "NASA's Oxygen-Generating Experiment MOXIE Completes Mars Mission" (Sep 6, 2023). https://www.nasa.gov/missions/mars-2020-perseverance/perseverance-rover/nasas-oxygen-generating-experiment-moxie-completes-mars-mission/
6. Basner M. et al., Mars-500 hypokinesis and sleep, PNAS 110(7), 2013. https://www.pnas.org/doi/10.1073/pnas.1212646110
7. Basner M. et al., Mars-500 psychological and behavioral changes, PLoS ONE 9(3): e93298, 2014. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0093298
8. NASA, "Mars Communications Disruption and Delay" (2023). https://www.nasa.gov/wp-content/uploads/2024/01/mars-communications-disruption-and-delay.pdf