Why NASA wants human guinea pigs to test out Martian living

Recently, NASA invited the public for a chance to go to Mars. Or, as close as you can get to Mars on Earth.

The space agency is seeking volunteers to test out living in the 1,700-square-foot habitat known as Mars Dune Alpha. They are trying to determine — as realistically as possible — how living on Mars would affect humans.

There are already four volunteer crew members living in that habitat, who entered in June 2023 and will emerge in July of this year.

To talk about what it might be like for humans to make it to the real Mars, and stick it out, behavioral ecologist Kelly Weinersmith joined All Things Considered host Scott Detrow.

Weinersmith is the co-author of A City On Mars: Can We Settle Space, Should We Settle Space, And Have We Really Thought This Through? alongside her husband, Zach Weinersmith.

This interview has been lightly edited for length and clarity

Interview Highlights

Scott Detrow: How hard would it be to survive on Mars? And what are some of the big examples that you came up with of just how challenging this would actually be?

Kelly Weinersmith: It would be pretty hard. Mars might look sort of Earth-like from the photos, but it's got some really unique challenges, like its atmosphere is only 1% of the atmosphere that we have here on Earth.

So you can't go outside without a spacesuit. There'll be no enjoying the feel of the breeze on your skin. You're going to need to suit up. And that also means that if your habitat ever depressurizes and you don't fix it fast enough, you would probably not make it through that experience.

We also don't really understand how Mars impacts the human body. We've had humans orbiting Earth since the 1970s, we have had over 600 astronauts go to space, but the space stations are orbiting under the protection of Earth's magnetosphere.

So they don't get exposed to the radiation that space has to offer, which differs from what we have here on Earth. So we actually don't know, for example, how much cancer risk would be increased in a place like Mars, which doesn't have a strong magnetosphere like we have on Earth and doesn't have a thick atmosphere to protect you.

That sand on the surface of Mars, it's actually called regolith. It's sharp and jagged and sort of laden with endocrine-disrupting hormones, which will mess up your blood pressure and your heart rates. So you're going to want to make sure that you don't grow your plants directly in that or let that get into your habitat.

And it's probably going to be cramped. Right now, it costs something like $300 to send just an apple to the International Space Station. It's going to cost way more to send it to Mars. And so you're going to have a pretty small habitat when you're initially starting out on Mars. So it's going to be cramped, and you better like the people you're stuck in there with.

Detrow: Why do you think they're such a draw then? This is a scientific goal not just at NASA, but at big, private companies like SpaceX, and more beyond that. It really seems like something embedded in our culture — this desire to get to the next big thing.

I feel like there are a lot of people out there, including the people who have volunteered to be locked in a room at the Johnson Space Center for a year, who have dreamed about maybe going to Mars one day. Why do you think that is

Weinersmith: I'm a sci-fi geek. I totally get it. The idea of waking up on the surface of Mars and seeing a Martian sunrise sounds absolutely epic. But there are people who have other specific reasons for going, and it sort of depends on the community that you're talking to.

The rotating space station community, which these days is led by Jeff Bezos, who has a rocket company called Blue Origin — they argue that living in these rotating space stations is going to save the Earth because you can move people off-planet to these rotating space stations. That's going to reduce the pressure on the planet Earth.

A lot of the Mars folks are excited about a chance to sort of start new governments and new ways of life, and a lot of them argue that Earth has become bureaucratic and wimpy and by going to Mars, we'd be able to start over again and sort of fix all the mistakes that we've made here on Earth.

And that community tends to be led by Elon Musk, who owns SpaceX. And Musk is also particularly excited about having a backup for humanity. So the idea that if humans are multiplanetary, if something happens to the humans on Earth, there'll be a backup so humans can continue on even if something happens to Earth. So there's a lot of different reasons for wanting to go to space, a lot of different camps, but for me, I think it's mostly awesome.

Detrow: So do you think there's value in these continued studies that NASA is doing? Do you think there's more information to gather about what this is like? Or like you said, is the track record pretty clear, and we know what the challenges would be?

Weinersmith: You know, so I love NASA, and I love their exploration missions. And I never want to really be on the record saying that I am not pro something NASA's doing, but here I go. To me, the value of these analogs can be measured in what you change about your mission plan when the analog is done.

If at the very end they said, 'OK, we know that humans can't survive isolated and confined environments for nine months because they end up hating each other, so we're not going to go.'

That would be a concrete thing. That's not going to happen here. And as far as I can tell, there's no specific piece of information they're going to get at the end of this one year or at the end of the three one-year stints, that's going to specifically change something about a plan for going to Mars.

We've had astronauts in space for more than 50 years. Surely, we can extract the data from what we know about what astronauts eat on the International Space Station. And this just seems like an incredibly expensive way to sort of validate that. And also, it's not even running for the full two years that you would need for a mission to Mars — because of orbital mechanics, it takes about six months to get there. You usually stay for about a year, [or that's what is suggested in] most of the proposals - and then a six-month trip back.

For two years, you're not even getting all the psychology information you'd need about how hard it is to live with four people for the whole length of time you'd need to be out there. So as far as I can tell, I'm not seeing the piece of information that's going to change our plans for going to Mars. Maybe I've missed it.

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