Suggested Searches

A Year in Mars Dune Alpha

Season 6Episode 7Dec 19, 2023

To prepare for the day when humans travel to Mars, NASA is conducting a one-year experiment in a Mars simulation environment. So what’s it like to spend a year in CHAPEA, the Crew Health and Performance Exploration Analog? In this season finale episode, travel through the airlock with voice recordings made by the four-person crew, including what it feels like—and smells like—inside their realistic 3-D printed habitat and how virtual reality gives them the sensation of walking on the Red Planet. NASA's Curious Universe is an official NASA podcast. Discover more adventures with NASA astronauts, engineers, scientists, and other experts at

This image shows a navy blue circle with a logo in the center that reads “NASA’s Curious Universe” in white letters with stars in the upper left and bottom right. Surrounding the circle, there are panels of shades of alternative reds and blues with red icons floating. The icons include a plane, planet Saturn, an asteroid with smaller rocks surrounding, a satellite, a question mark, a telescope, molecules, and part of a visualization of a black hole.

Episode Description: 

To prepare for the day when humans travel to Mars, NASA is conducting a one-year experiment in a Mars simulation environment. So what’s it like to spend a year in CHAPEA, the Crew Health and Performance Exploration Analog? Travel through the airlock with voice recordings made by the four-person crew, including what it feels like—and smells like—inside their realistic 3-D printed habitat and how virtual reality gives them the sensation of walking on the Red Planet. NASA’s Curious Universe is an official NASA podcast. Discover more adventures with NASA astronauts, engineers, scientists, and other experts at


Anca Selariu: Hello earthlings. 

Nate Jones: Hello.  

Anca Selariu: It is September 18. This is Anca and Nate, and we are currently in the airlock. 

Nate Jones: There is air in the airlock right now, thankfully. 

Anca Selariu: (whispering) …This is what Mars airlock sounds like.  


[Sound of airlock room tone] 


HOST PADI BOYD: This is a message from Mars Dune Alpha.  


[Song: “Lockdown Anxiety” by Jez Hurst and Thom Powell] 


HOST PADI BOYD: Inside this habitat, four intrepid crew members are surviving in a foreign, isolated home. They work together. They eat together. And occasionally, when they need to suit up and leave the safety of their habitat, they go through the airlock.  


Ross Brockwell: This is where we put on our spacesuits, and it’s where we equalize pressure to either exit or re-enter the habitat. 


[Sound of latch closing] 


HOST PADI BOYD: If you’re thinking to yourself, “I thought there weren’t any humans on Mars,” yep, you’re right. But this mission will help us get there. It’s called CHAPEA: Crew Health and Performance Exploration Analog. Before NASA sends humans to Mars for real, we’re practicing here on Earth at a specially designed Mars habitat at NASA’s Johnson Space Center in Texas. The crew gave us an inside look. 


Nate Jones: We have a window that we use—air quotes around the word “window”—that it uses a TV with a video feed of the outside of our habitat. And we can see the Martian sunrise with it out the window. And then the sun basically goes over our head, and we eventually see the shadow of our habitat on the ground. And eventually, throughout night we see the stars. 


Anca Selariu: And it’s really pretty. 


Nate Jones: If I could sum up CHAPEA in just a couple of words, the words would be “almost Mars”. 


[Theme song: Curiosity by SYSTEM Sounds] 


HOST PADI BOYD: This is NASA’s Curious Universe. Our universe is a wild and wonderful place. I’m your host, Padi Boyd, and in this podcast, NASA is your tour guide. In this episode, we go inside CHAPEA. NASA scientists and researchers want to know, what happens when astronauts are cooped up for a year with the same three people and have to manage the stress of surviving in a Mars-like environment?  


CHAPEA will shed light on those questions, like a dress rehearsal for life on Mars. So what’s it like to live in Mars Dune Alpha for more than a year? We’ll find out through dispatches recorded by crew members during the mission. We’ll also learn what it sounds like and smells like inside their Mars habitat,   

hear how the crew uses virtual reality to make Mars spacewalks feel as lifelike as possible, and explore how the CHAPEA crew is paving the way for the first human mission to Mars. 


It’s been more than 50 years since humans last left footprints on the Moon.  NASA is getting ready to send astronauts back. Not only will the Artemis program put the first woman on the moon, it’s going to establish a long-term presence that we’ve never had before. And we’re not stopping there.  


Grace Douglas: You know, we’ve worked so hard in the space program to get to the moon, to try and go back to the moon. And we’ve been working really hard to try and make that path achievable to then go on to Mars. 


HOST PADI BOYD: Like any NASA mission, CHAPEA involves a big team working together. Besides the crew members in the Mars habitat, there are engineers who designed the Mars environment, including red dirt for spacewalks; experts in behavioral health who helped pick the crew; and a mission control team acting as their lifeline. And one scientist outside the habitat who oversees it all.  


Grace Douglas: I’m Dr. Grace Douglas. I’m the principal investigator for the Crew Health and Performance Exploration Analog or CHAPEA. 


[Song: “Into the Void” by Gage Boozan] 


HOST PADI BOYD: Grace is based at NASA’s Johnson Space Center in Texas. CHAPEA builds on decades of research into human spaceflight, and it follows NASA’s long-term plan to go back to the Moon and beyond.  


Grace Douglas: It was a very wide effort to make sure that we were getting all of the expert perspectives for what we believe a Mars mission will look like to make it as realistic as possible. 


HOST PADI BOYD: At NASA, we don’t do anything until we practice, practice, and practice some more. That goes for living on Mars, too. The CHAPEA mission started in June 2023, and it runs until the summer of 2024. 


Just like on Mars, the four CHAPEA crew members can’t leave their habitat, except for short excursions outside in a spacesuit. And like astronauts on the International Space Station, the crew has limited food and water, limited time, and a task list to accomplish each day, like conducting science experiments or maintaining equipment. Also, it’s not easy to communicate with Earth. If there’s an emergency, the crew can’t pick up the phone and call mission control. 


Grace Douglas: When we close the door in that habitat, they are in there for the year. we also can simulate the time delay. We’re expecting a lengthy time delay, with all communications for a Mars mission. So instead of voice communications, everything is written or sent by video. And there’s limits on how much data can be sent. 


HOST PADI BOYD: All of those factors add stress—the kind of stress that a real Mars crew will also feel. One of the things the investigators are measuring is how that stress impacts the crew’s health and performance. Of course, there are some things about the Martian environment you can’t simulate in Texas.  


Mars has about a third of the gravity of Earth. A person who weighs 150 pounds here would only weigh about 56 pounds on Mars. You also can’t really fake the Martian atmosphere, which has almost no oxygen. If you stepped outside without a spacesuit, you’d be toast. Even the surface of Mars is different. It’s covered in a rocky, dusty layer called regolith.    


Grace Douglas: Things like the regolith, they don’t have to be 100 percent simulated to get that data. Things like the spacesuit don’t need to be 100 percent. We need to get the load on the crew, the kind of experience that that crew would feel and have to work within in order to do their activities. So we are able to do that fairly well with these simulations. 


HOST PADI BOYD: Throughout the experiment, Grace’s team is measuring health and performance data. That includes collecting blood samples, as well as measuring cognitive performance. Going to Mars involves a balance between the resources you have and the risks you’re willing to take. All of that data will help NASA make the best decisions to keep the crew healthy and for mission success.  


[Song: “Exoplanet” by Jeff Penny] 


HOST PADI BOYD: With the experiment set up, Grace needed a crew: four capable people willing to leave their jobs and families here on Earth for a leap into the unknown. NASA opened up the program to the public, and more than 4,000 people applied. So Grace’s team had to choose the best of the best.  


Grace Douglas: We have a similar process to what astronauts would have to go through for a selection for a mission like this because it is expected to have a lot of the similar attributes and stresses that astronauts would experience and challenges that they would experience. 


HOST PADI BOYD: We met the crew three months into their time in the Mars simulation. Since there’s no live communication, they recorded voice memos about their experience. Just like astronauts, the CHAPEA crew had to fit certain physical criteria. They also have backgrounds in science or engineering. And they signed up to leave behind Earth and everything on it—including their friends and families—for more than a year. All four of them were intrigued by this new challenge.  


Anca Selariu: I was browsing NASA’s webpage. And that’s how I came across the announcement.  


HOST PADI BOYD: This is Anca Selariu.  


Anca Selariu: And why I wanted to be a part of it? Because it’s—going to Mars is a natural next step for humanity. It’s just requirement for human evolution in my opinion, and I’ve always wanted to somehow participate. 


[Song: “Robot Reborn” by Danny Cullen, Nick Herbertson, and Tord Jungsten] 


HOST PADI BOYD: Anca is a microbiologist in the U.S. Navy. In CHAPEA, she’s the science officer: the person in charge of research that happens inside the habitat. 


Anca Selariu: My job is to do an analysis of geology samples that we collect from the Mars surface; also perform some biology experiments trying to grow crops.  


Nate Jones: Yeah, I also came across it online, a write-up on the web for it. And then I think the big thing kind of propelling me would be kind of just a sense of adventure and, you know, just getting to contribute to that next step to Mars. 


HOST PADI BOYD: That’s Nate Jones. His background is emergency medicine, so he’s CHAPEA’s medical officer.  


Nate Jones: It’s my job to ensure that biological information can be collected and that the specimens are all ready to go. It’s my job to send them off to NASA for analysis after they’ve been collected. If a medical emergency were to occur to a crew member, I would provide immediate medical assistance. 


HOST PADI BOYD: Up next is Ross Brockwell. On Earth, he’s an engineer who works in city planning.  


Ross Brockwell: I’m the flight engineer for CHAPEA mission one. I’m responsible for many of the habitat systems, so making sure that they’re operating properly and maintenance activities and schedules are kept. 


HOST PADI BOYD: And last, but definitely not least, is Kelly Haston. She’s a stem cell biologist, and she’s the commander for CHAPEA.  


Kelly Haston: A lot of people ask, “what does the commander do?” and to be honest it’s not the most glamorous job. So every single crew member takes part in all of our activities, so we all do similar things most of the time. 


[Song: “Results Take Time” by Paul Richard O’Brien] 


HOST PADI BOYD: Life in CHAPEA revolves around the habitat, aka “Mars Dune Alpha”. The whole thing is 1,700 square feet or about the size of a medium one-story house. Each crew member has their own small bedroom, plus there’s a communal area and a few specialized work spaces. NASA experts think that in the future, we might be able to 3D print buildings from the Martian soil. So the walls and ceiling of Mars Dune Alpha are all 3D printed out of a red, concrete-like material. 


Kelly Haston: People often ask what it smells like. It doesn’t actually have a lot of smell. And one of the reasons is that most of the items that we brought in or that were supplied to us as, you know, things that we’ll use during the mission, are made to not have a scent.  


HOST PADI BOYD: It turns out that strong scents can be harmful to some of the machines that make space travel possible, like water reclamation systems.  


Kelly Haston: In our normal life we’re used to our laundry detergent having a scent and maybe wearing perfumes or having, you know, hand creams that smell very strongly. And in this case, we actually have very little of those things. So the number one thing we probably smell is food and only when we’re eating. I do have a bar of soap that I keep that does have a particular smell that I like, though, and sometimes that’s a way to sort of, like, feel comforted.  


[Sound of 3D printer whirring] 


HOST PADI BOYD: All over the habitat, the crew hears a steady stream of machine noises. Like this sound of a 3D printer in action, which they can use to make parts for their equipment. 


[Humming sound of instruments charging] 


HOST PADI BOYD: In the workspace, there’s also a bank of instruments and machines charging. It takes a lot of noisy machinery to keep the habitat running. 


Anca Selariu: You hear a constant hum. I like to imagine it as the engine of Mars. You know, the heart of Mars. 


Nate Jones: I think there’s just a whole lot of white noise. It’s actually—we kind of I think tuned it out by now in general. But I do remember when I first came into the habitat, just how noisy it was. Air through vents, fans, the computer, the PCs running their fans, and all those sorts of things are quite a bit of white noise. 


Kelly Haston: This is Kelly. We are in the exercise bay of Dune Alpha, and this is the sounds of a crew member doing a workout on the rowing machine. 


[Sound of rowing machine] 


HOST PADI BOYD: In microgravity, astronauts lose muscle mass and bone density without regular exercise. It’s crucial to give the crew a way to stay in shape, so one of the specialized rooms in the habitat is a small exercise area. There’s also a medical bay, which looks more or less like an exam room at the doctor’s office. Each day starts in the common area. That’s when the crew goes over their assignments.  


Kelly Haston: We do get up each day around the same time, around 6 a.m. We start our day. We congregate in the kitchen, have a meal, but then each day can be really diversely different. 


HOST PADI BOYD: Inside the habitat, the crew is growing a few crops so that they can have fresh food, so some days include gardening. On other days, they conduct geological experiments on the simulated Martian surface. But the crew’s favorite days are when they get to leave the habitat.  


[Song: “Horizon” by Paul Richard O’Brien] 


Normally they wear Earth street clothes, but when it’s time to leave the habitat they don a spacesuit and head out through the airlock. These spacewalks are called EVAs, or extravehicular activity. Here’s Kelly again.  


Kelly Haston: We are in a sort of simulated spacesuit-type outfit, so you really get that sense of being out in the Martian environment and experiencing the sort of physical load of moving around in a heavy spacesuit with gloves on.  


HOST PADI BOYD: Just outside the habitat, the crew has an area called the sandbox. It’s a domed room that mimics the surface of Mars, right down to the red dirt and walls with pictures of red hills that fade off into the horizon. The sandbox gives the crew a chance to walk around in their spacesuits and complete missions, like maintaining equipment or studying the Mars surface. Anca says some EVAs are even more immersive, with virtual reality goggles that put you inside the Martian landscape.  


Anca Selariu: I love going on the on the EVAs because they really feel for me like I am walking on the surface of Mars. It feels it feels kind of slightly difficult because we have a simulated spacesuit. 


Kelly Haston: So we’re on the treadmill, and then we have VR goggles on. And that enables us to actually have the physical feeling of activity, as well as seeing Mars at the same time. The Martian landscape in VR is just really, really nice. It’s beautiful. And oftentimes, I will look out as I’m walking and really appreciate the vistas of the different mountains we’re looking at or different landscapes, and it’s really cool to be there. 


HOST PADI BOYD: Until humans make it to the real Mars, this is about as close as anybody will get to walking on the Red Planet.  


Nate Jones: I would say Mars is very sandy. Sand everywhere, dust everywhere. I will say that the EVA days are long days. They’re hard days. We get worn out.  


Kelly Haston: It’s really amazing how fun it is out there, how hot and sweaty you get.   


Nate Jones: Usually we come in and our EVA flight suits are soaked in sweat and to the point where—you know, this kind of a gross picture, but afterwards, like a day later, you can come and see these black flight suits and they are just caked in white salt from sweat.  


Anca Selariu: Humans certainly contain a lot of salt, don’t they? 


Nate Jones: So we have to take steps to mitigate that.  


HOST PADI BOYD: In all, the crew normally works five and half days a week—similar to astronauts on the International Space Station. So what does the crew do with the rest of the time? Well, even on simulated Mars, you need to unwind after a long day.  


Kelly Haston: We do get downtime. We have a few board games in here, and we also watch a little bit of TV together. So we were able to bring in a certain amount of data, and we all collaborated to bring in different shows and movies. So we pick a show and we watch it together. So it’s kind of interesting to both work and play with the same three people for a full year. And we also get some alone time where you can spend time by yourself. I’m a big reader, so I read a lot, and I also like to do crafts. So I’m doing some knitting. I’m learning to crochet. Several of us have musical instruments and spend some time playing those in our downtime. 


[Song: “Wavelength” by Adam Salkeld] 


HOST PADI BOYD: The CHAPEA crew members ended up here because they’re overachievers. They knew what they were signing up for: a year of isolation; a year away from their friends and families; a year with no sunlight, trees, or fresh air. But even if you volunteer for that, it’s still difficult to actually do it. Here’s Anca and Ross. 


Anca Selariu: I really miss driving. I miss seeing trees. I miss seeing green. I miss the colors, the seasons. I miss everything about Earth. 


Ross Brockwell: So once CHAPEA ends, what Earth activity am I most looking forward to? Well I’m definitely looking forward to jump in the ocean and lying out in the sunlight. I’m really looking forward to enjoying nature in general—everything our home planet provides us. 


HOST PADI BOYD: Also, the crew can’t talk to their families in real time. They send emails back and forth, and sometimes they can include attachments, like video or audio messages.  


Kelly Haston: I think you realize how much you rely on people without even realizing it. I didn’t think it was easy for to be away from my family, but you think you’re going to manage it but it is actually really, really hard. 


Anca Selariu (to Nate Jones): If you were to send an audio postcard to a family member right now, Nate, what would you tell them? 


Nate Jones: Just that we’re having a great time and I hope that they’re doing well and enjoying their time on earth. How about you, Anca?  


Anca Selariu: I would say thank you for everyone who is helping me with my life outside, and thank you everyone who’s sending me articles on the latest physics discoveries and other news of Earth. It’s really meaningful for us to have that communication, and it makes us feel like we still belong to people’s lives. So thank you. 


HOST PADI BOYD: It will be a few more months until the crew returns to Earth in July 2024. After that, their portion of the experiment is done. But CHAPEA is just beginning. This mission is CHAPEA One. Grace, the lead scientist, is already planning to run the mission again.  


Grace Douglas: We really need to repeat it with different crews, with different individuals and understand statistically what was an anomaly versus what’s an outcome that we can expect to see over and over again.  


HOST PADI BOYD: In the next few years, a new crew will repeat the mission as CHAPEA Two and then again with CHAPEA Three. So the researchers don’t want to give away too many details about the experiment. Over time the science team will publish research papers with findings about crew health and performance throughout the year. Grace says that rigorous data is what it takes to build the path to Mars. 


Grace Douglas: It’s all steps to getting them there. So our crews that are part of this now, our team members that are supporting the mission—we’re all part of it. 


[Song: “Between Surprise and Fear” by Alan Myson] 


Anca Selariu: When I imagine the day that the first human will leave a footprint on Mars, I see an entire world stopping and watching. I see the world of humans being infused with hope.  


HOST PADI BOYD: When the first humans do walk on Mars, their names will join Neil Armstrong, Sally Ride, and other pioneers who pushed humanity further. The CHAPEA crew knows they won’t get the same recognition, but they’re building the foundation for the first human mission to Mars, whether those future astronauts know it or not. 


Ross Brockwell: I guess it would be pretty cool if that first crew was aware of us and they were appreciative of the efforts we put into this study. 


Kelly Haston: And I actually kind of hope that if we do our job well here, they won’t think about us at all. You know, science is an iterative process. You iterate on things. You make small discoveries that build and build. You know, some people are lucky and have really big, you know, discoveries, but oftentimes it’s little tiny pieces. And I think that this study is an example of that.  


Anca Selariu: The first Mars crew doesn’t have to remember the names of the CHAPEA crew. But I know this: they will definitely be representing our spirit, the same spirit that the first humans that saw a body of water and carved a boat, a rudimentary boat out of a log. Every day I’m amazed and grateful to be here. I’m amazed that I can actually contribute to the same exploration that we have been carrying on for all these decades and centuries and millennia since we’ve appeared on the planet. 


HOST PADI BOYD: This decade NASA astronauts following in the same spirit of exploration will leave the first footprints on the Moon in more than 50 years. The Artemis program will open a new chapter of human exploration with consistent access to the Moon. And after that, we’ll look even further. 


HOST PADI BOYD: Who will eventually take the first steps on Mars? We don’t know. As Artemis brings humans back to the Moon, that Mars astronaut may be dreaming about their own place in the stars. The CHAPEA crew is taking one small step so that whenever the time comes, humans can make our next giant leap.  


[Theme song: Curiosity by SYSTEM Sounds] 


This is NASA’s Curious Universe. This episode was written and produced by Jacob Pinter. Our executive producer is Katie Konans. The Curious Universe team includes Christian Elliott, Maddie Olson, and Micheala Sosby. 

Our theme song was composed by Matt Russo and Andrew Santaguida of SYSTEM Sounds. Krystofer Kim is our show artist. Special thanks to Anna Schneider, Greg Wiseman, and the CHAPEA team. 

If you want to know even more about CHAPEA, we’ve got you covered with another NASA podcast. Check out Houston We Have a Podcast. Every month, hear a new audio update from the CHAPEA crew. And follow Houston We Have a Podcast for in-depth coverage of NASA’s human spaceflight program.  

Thank you for tuning in to the sixth season of NASA’s Curious Universe. We’ve enjoyed taking you along with us as we’ve explored our wild and wonderful universe, from dark matter and dark energy to the hum of the Sun and so much more. We’re taking a break, but we’ll be back soon with more adventures. 

Until then, you can continue exploring with NASA by visiting And find even more NASA podcasts in your favorite podcast app or at 

If you like NASA’s Curious Universe, please let us know by leaving us a review and sharing this episode with a friend. And remember, you can follow NASA’s Curious Universe in your favorite podcast app to get a notification each time we post a new episode.  


Nate Jones: Yeah, NASA was kind enough to provide us with quite a few pictures of nature. And it was it was a great thought, though I am wondering why they chose to put the picture of the one alligator in my room. Not sure if they’re trying to tell me something with that or not.