The next class of astronauts will be selected from thousands of applicants. Some of them may walk on the moon or be the first to set foot on Mars. NASA’s astronaut selection manager Anne Roemer stands with the most recent class of astronaut candidates selected in 2017 from more than 18,000 applicants. The 2017 class graduated this year. NASA’s next space travellers are vying for the job—by the thousands. During a brief window in March, 12,040 hopefuls applied to be members of the space agency’s next class of astronauts. The first round of on-site interviews, originally scheduled for late September or early October, has been pushed back to next spring because of the pandemic, says Anne Roemer , NASA’s astronaut selection manager. “Now we just have more time to scrutinise the applications.” Even without a pandemic in play, choosing NASA’s professional space travellers is no simple process. Astronauts need to be disciplined yet flexible, adventurous yet safety-conscious, capable of leading and following. They must possess a certain je ne sais quoi —in other words, the “right stuff.” To find the optimal candidates, Roemer and a panel of current astronauts are scrutinising the thousands of applicants to identify a dozen or so with the right mix of characteristics and experiences to join what could be the most exclusive corps on Earth. One of the people they select could even be the first human to walk on Mars. Roemer spoke to National Geographic about how NASA chooses its astronauts, what she’s looking for in candidates, and what she thinks about being inside the current fleet of space capsules. The following interview has been edited for length and clarity. (Find out how the “right stuff” has changed since the early years of the space program .) How many people are you expecting to select for the next astronaut class? We always leave ourselves some wiggle room so we can keep track of attrition—who’s left the astronaut office, who’s retired, who’s told us they may not want to fly again, et cetera. I’d say we went in with a rough estimate of eight to 12, and the longer we push making a decision, that number may get closer to 12. What is the selection process like? We start by reviewing the written application materials, and that’s our first window into each applicant. Then we do some reference checks as we narrow down the number. Ultimately, we get to the point where we invite around 120 to the first round of interviews. We start doing some skills analysis and some basic medical testing, and then we end up inviting between 40 and 60 folks back for the second round of interviews. During the second round, they spend about a week with us. We do some team reaction exercises, individual performance exercises, and a bunch of things to assess whether they have the competencies that we’re looking for to be a good astronaut. The application criteria were different this time—what changed, and why? In the last selection cycle, we received over 18,000 applications. This year, we required a master’s degree. We had always stated that a master’s degree was preferred, but [this time] we were just more overt, because when we looked back at our last classes, we really hadn’t selected anyone with just a bachelor’s degree. What helps applicants stand out when you’re reviewing 12,000 applications? We tend to focus on operational experience in situations where they’re going to have to make real-time decisions in a relatively high-stress environment. Not everyone has operational experience in the course of their day job, but there are ways to get that. We see a lot of people who go to the Antarctic or do wilderness rescue. A lot of people choose to get their private pilot’s license. Teamwork and leadership experience throughout their resume is also important. And then I’ll tell you, honestly, sometimes when you’re reviewing that many resumes, it’s the unique things that grab your attention. We give applicants a section to tell us about their hobbies and interests, and we see people who have done all sorts of things, whether it’s running 25 marathons or completing 300 scuba dives. What are some of the more memorable hobbies that you’ve come across? We see a lot of people pursuing high-stakes athletic endeavours. Some of them have hobbies in the fine arts, as well as being obviously very scientific and in the STEM field. I’ve seen a little bit of everything. Probably one of my favorite resumes I read, though—before we put in any kind of screening measures—was a creative writing application. And they graduated from Hogwarts. And their first job was at SNASA, which was Secret NASA. What are some of the personality characteristics that you’re looking for? Interpersonal skills are key: teamwork, followership, leadership, communication skills. Not only in ideal situations, but how do you communicate with others under stress? We’re really, really looking for all of that. I think when you talk to other astronauts who have flown and who then sit on the board, they kind of sum that all up with the question: Would I want to fly with this person? When it comes to thinking about missions to the moon, and our goal to get to Mars, you’re talking about a really long-duration mission. So I think they’re evaluating, OK, could I be locked up in a tin can with this person and feel safe, like I’m in good hands, and really get along with this person and have a courteous relationship? What are some of the characteristics that help people to be better suited for long-duration missions? I think it’s probably a passion overall. You see a lot of people with extreme environment experience, and they work well on teams, but can also survive and perform as an individual, if needed. I think it’s a little bit of everything. There are times, like an emergency situation, where you may need to be the one in charge and the one issuing orders and commanding respect. There are other times when you might be following the orders that mission control sends up. It’s knowing how to modulate your skill set, and maybe even your personality, to be prepared for what’s needed at the time. Does the team that assembles mission crews let you know if there are any specific holes or gaps that they’re trying to fill when you’re picking the next class? Yes, to the extent possible. An example is pilots in particular. Even though we are not flying the shuttle, the astronauts still rely heavily on the T-38 jet as a training vehicle. So there is still a strong desire to have several pilot astronauts who can fly with other crew members. Are you ever looking for a particular type of scientific or engineering background? If we get back to planetary or surface missions, maybe. In the Apollo era, they knew they wanted to send a geologist in particular to the surface of the moon. So I think that’s always a possibility. With the increased variety of spacecraft that astronauts could fly, does that cause you to pick people differently than if everybody was flying on the same kind of vehicle? It really hasn’t. From a selection standpoint, it’s actually opened the window a little bit as far as the anthropometrics go. If we were continuing to fly only Soyuz [Russia’s space capsule], there are very strict height and weight limitations, like the length from the astronauts’ hipbone to their knee bone. If they’re too tall, they can accidentally push buttons that they shouldn’t push. So it’s really opened the door, having multiple vehicles again, from a height and size perspective. That’s not something I had even thought about. Yeah, the Soyuz is probably the most restrictive, right? I don’t know if you’ve seen the inside of that, but you couldn’t pay me a million dollars to get in that thing. Would you personally get in a SpaceX Dragon capsule, now that those are being flown with a crew on board? Compared to the Soyuz, that looks really spacious. I’m mildly claustrophobic, so I prefer to be on the ground and able to open the window and go outdoors whenever I choose. I’m happy on Earth. When you’re looking at the applicants now, are you thinking about them potentially being the first humans on Mars? Or are those folks already in the astronaut corps? Probably both. As we look at going back to the moon by 2024, that’s somebody who’s already here. I think we’re all hoping that someone from the last class, or this next class, could be the first person on Mars.