I remember a talk by a NASA guy that a first try would be to land some people with limited supplies on the Antarctic and let them live autonomously for a few years. He said before we go to Mars we need the ability to do this easily.
1. They have a small group of 50 people. Issues with crew psychology and relationships are mostly covered.
2. They live entirely indoors in small, manmade habitats. They're actually under the snow in much the same way that Martian hab units would be under regolith.
3. They are autonomous. It's completely up to them to survive the winter.
Yes, they're not doing the full biosphere thing - they're surviving on rations brought in by airplane, and breathing the outside air after just heating it - but that's pretty close.
I also think of people on strategic submarine ballistic missile nuclear boomers. They're shockingly big boats, but the crews are in a limited space with a limited air supply and no views of the outside for 70 days at a time. I would be unsurprised if the public information on their maximum deployment times for crews (said to rotate out every 10 weeks) has been exceeded, and I'm sure the navy has studies on it. Also living off rations, but similar.
It's probably more conceivable and informative to try to grow rations in a lab using the constraints that would be placed on martian astronauts than to convince a crew to do the Amundsen-Scott experience or SSBN experience, but with also growing your own food.
Though I imagine after 8 months of Antarctic winter, a salad would sound pretty good...
I understand that's what the estimates say, but how is that reasonable? The mars mission would include a biosphere of some kind, right?
Is the Biosphere 3 estimate far too high? Or is the Mars mission estimate far too low?
You want to send the best version possible to mars and not do your survival learning there. Some will of course be unavoidable but much can still be learned here on earth.
If the first one fails, how likely are we to continue doing it, considering the present challenges we face on Earth?
There's no earthly reason to make people live in the Atacama, but then again, there's no reason to send people to Mars, either.
Another "advantage" of interior Antarctica is that, in winter time, it is difficult-to-impossible to actually get in or out of it. The Amundsen-Scott research base is isolated for three months of the year, although two medevac flights have been done in winter.
https://www.theatlantic.com/health/archive/2015/02/how-to-su...
Well, since they mention that water as ice is actually abundant[1], it's probably good for testing out strategies for harvesting and purifying water effectively and reliably at the same time they are dealing with the other problems.
1: From the article: Water is a mix of hydrogen and oxygen and is abundant in the form of ice mixed into the top meter of the Martian regolith. Around the equator and up to 60° latitude it varies in concentration from 2-18% but further north and south it’s in even higher concentrations, reaching 100% at the north pole.
Of course since we are on earth either way a rescue plan is at most a few days away (generally hours but bad weather might stop your efforts for days).