nce upon a time I lived on Mars. Or the closest thing to it. At the time I was a science journalist and not necessarily an obvious choice for the mission. And yet I found myself on it. This was 2012 and Kim Binsted, professor of information and computer sciences at the University of Hawaii, along with Jean Hunter, professor of biological and environmental engineering at Cornell, had put out a call for “almost” astronauts to participate in a four-month “Mars” mission. Binsted and Hunter wanted a crew who could technically qualify for space flight, according to Nasa, in terms of education and experience. They were also looking for astronaut-like personalities who, according to Binsted, feature “thick skin, a long fuse and an optimistic outlook”. Nearly 700 people applied worldwide. Somehow they chose me and so, between April and August 2013, I lived with five other not-really-astronauts in isolation, all of us making various Martian concessions, like mostly bathing with wet wipes, forgoing real-time social media and zero access to fresh fruits or vegetables. We lived inside a large, white geodesic dome off an access road at 8,000ft on the Hawaiian volcano of Mauna Loa. The scene was very red, very rocky. Very Mars. There was limited electricity and water. We could only leave the dome wearing bulky, cumbersome, space suit-like outerwear. While we had an emergency mobile phone, our sole regular contact with Earth was through email. And since Mars is extremely far away, our email transmissions were delayed by 20 minutes each way to mimic the actual communication lag to be experienced by Martian explorers. It wasn’t your typical Hawaiian vacation. All for science, though. Binsted and Hunter’s main research question regarding food was this: might it make sense to allow astronauts to cook their own meals once they’ve landed on Mars? Data has shown that astronauts on six-month missions on the International Space Station eat less over time and lose weight, making them more prone to illness and injury. Binsted and Hunter wanted to measure the importance of cooking, and meals in isolation more generally – how food affects a crew’s physical, mental and social health. On Earth it might be obvious that food is more than just sustenance for a body, that it plays a psychological, social and cultural role, and that it nourishes the spirit and our relationships with others. But to ask complex questions about the role of food on a Mars mission and base a brand-new Mars analogue around these questions? It’s pretty radical, actually. And so, for this food study, we ate a combination of pre-prepared meals, as well as meals we cooked in our small yet well-equipped Martian kitchen. We logged the changes in our appetites and weights and took tests to measure our ability to breathe through our noses and to identify odours, all of which relate to hunger and food satisfaction. There were nearly a dozen other experiments, too – trying out antimicrobial socks, tests of mental acuity, behavioural surveys, the list goes on. We lived and breathed survey questions for four months. Four months of isolation. Four months of the same people, same seats at the table, same clothes, same smells, same routines, same view outside the one-and-only window looking out on to the same rocks. No sunshine on our skin, no fresh air in our lungs. I don’t want to overstate the difficulty – we were never in any mortal danger. But there were some aspects of the experience that I did find trying. I missed face-to-face conversations with my wife. I longed for a change of scene and better indoor lighting. A swim in the ocean or a pool. A walk in the woods. We were warned about the effects of isolation in small and large ways. The small ways: brief mentions during our pre-mission conference calls about tensions that arise between crew members and their friends, family and mission support back home. The large ways: the multiple hours-long discussions to discover what our breaking points would be. Would we abandon the mission if we got a sudden job offer? If someone back home got sick? If someone died? If we got sick? How sick? Mentally? Physically? If we lost faith in our crewmates or the project entirely? And how did we plan to manage the well- documented challenges of isolation? These challenges included, but were not limited to, something scientists have called “third-quarter” syndrome, in which the itch to be anywhere but inside the dome with your five best friends flares hot when the end is in sight but not quite within reach. Diaries from Arctic and Antarctic expeditions suggest that it’s a special time, three-quarters into your mission. You’ve become used to your routines and found a rhythm, but the hard reality of being cut off from others, the demands of your duties and the quirks of your crewmates have started to wear on you. Here, I was guilty, somewhat predictably. As a writer, I tend to notice the little things. Minor, finely detailed irritants snuck up on me and then kept flicking the back of my head. The number of times in a row I replaced toilet paper in the first-floor bathroom. The cadence of a crewmate’s hard-soled sandals galloping down the stairs, remarkably consistent and always so loud. I also wondered why one of my crewmates kept swinging her crossed leg under the table at every meal so as to ever-so-gently tap me in the shin with her fuzzy slipper, seeming to reach across an incredible distance to make such slight contact, even after I’d tucked my legs well under my chair. But what I really wondered was, why I couldn’t ask her to stop? Does all this make me sound a little unstable myself? Unsuited to living in an isolated environment with other people? Maybe. But I know I wasn’t alone. One crew member complained of another’s frequent throat clearing. Another suspected that his position on the chore chart was unfair because it gave him too many back-to-back heavy tasks. Then, when he traded with one of us and found himself in an even worse chore lineup than before, he became more frustrated. Our crew got along reasonably well – I’d say functionally most of the time and even jovially harmoniously on occasion – but some personalities did clash. There were a couple of yelling bouts and some isolation-within-isolation events –that is, going to a room and staying there for a longer than culturally accepted period of time. We’d developed our own culture for what was socially expected, but for some of the crew whose personalities weren’t well suited to the agreed-upon social interactions, this proved to be a strain. Most of us are still on good terms, though a couple of us don’t speak to others. One of us moved to New Zealand about a year after and hasn’t been in much contact since. Yet while we were together, our mission depended on our faith in and understanding of one another, our conversational shorthands, knowing when we were serious and when we were joking, and the subtext and motivations behind it all. How unsettled I felt in the first few days back, answering interview questions from news media and from people in general. It might sound strange, but I wondered who I could trust. I had spent more than four months building a particular and insular kind of camaraderie with my crewmates. But how to be with other people? Outside that dome, suddenly I wasn’t so sure. We have all known discomfort, dislocation, sadness, loneliness, or the frustration of feeling isolated in some way or another. Here on Earth, there are many isolations, some torturous and immoral, some useful, some natural, some finite, others indefinite. And, of course, the one that impacted our world for most of 2020 and beyond – the pandemic – cloistering us in fear, shrinking our geographies for the sake of stemming the spread. More than ever we know isolation can be life-altering in all its forms. I didn’t know it at the time but, over the years, I have come to realise this: Mars changed me. The science of that mission spilled over and mixed with the personal experience of the project. The quotidian survey questions such as, how hungry are you? How full? Who did you interact with the most today? The least? What was the best thing about your day? What was the worst? Somehow began to feel like larger inquiries relevant not just to an astronaut on a space mission, but to me, personally, or to anyone. Issues like communal versus individual food stores, whom you trust, how to behave when privacy is at a premium and when resources are scarce. These are exactly the issues that are relevant to larger communities, to nations and the entire world. Somehow the research questions on an imagined Mars mission have sprawled beyond their intended bounds. I could see how they were about everything and all of us. In the days and weeks after our return, my crew and I ate fresh fruits and vegetables that crunched in our mouths, we swam in the ocean, and we debriefed with Binsted, sharing some of our more personal and poignant observations during the mission, all in service, we believed, of a better imagined future trip to Mars. Those early days back home are something of a blur, though I do recall the intensity of certain sensations. Loud noises easily startled me. It took days for me not to notice even the slightest breeze on my skin. For a long time too, I struggled to find the best way to convey my experience. I avoided the immediate media flurry, the phone and television interviews. I simply couldn’t find the soundbites. I had come into the experiment as a journalist and as a kind of citizen-scientist. Most news reporting aims for a kind of objectivity and to tell a story with authority. But to me, the story of my Mars felt shifty, my telling of it variable. I didn’t feel comfortable saying I knew what any of it really meant. And it wasn’t just about what happened on the mission or inside the dome. It’s reverberated out, touching everything in my life. The HI-SEAS mission did indeed change what I think about space exploration. But it also helped me to pay more attention, generally. I’m talking about my relationships here, to people and to my home planet that, I must admit, I never saw with as much clarity as I did in those first few weeks immediately after the mission ended. In the years since, I’ve become a stranger in many ways to the person who first entered that Mars dome on Mauna Loa. I write less journalism, more essays and poetry – more interested, I suppose, in the subjective and associative, in mystery and in looking at a thing from the side rather than straight on. I’ve changed jobs, gone back to school and moved across the country. I’ve made and lost friends. My oldest brother has died. My long relationship with my wife has ended, and I am, for the first time in 14 years, living on my own, thinking a lot about the meaning of home, the meaning of exploration and isolation, of collaboration and partnership, of the various ways stories are told, and of beginnings and ends. When an astronaut comes back, Earth isn’t where it was. The whole system has shifted from underneath and all around, which is of course just the imperceptible hurtling of our local galactic arm. “There is no there there,” as Gertrude Stein said of Oakland, which as an adult she found unrecognisable from the city of her childhood. It’s like anything, though. You leave and come back, and home isn’t what it was. But sometimes leaving is the only way to know it was ever home in the first place.