Two astronauts are stranded in space. This one is jealous.

Most people are now probably familiar with the story: Two American astronauts were sent to space on an eight-day test mission on a new Boeing spacecraft in June. Now, nearly three months later, NASA announced that they’ll bring the astronauts back on a SpaceX Dragon capsule — which will not arrive until February 2025 for the return flight.

Barry “Butch” Wilmore and Sunita “Suni” Williams, both veteran Navy pilots, rode in the Boeing Starliner capsule’s first crewed flight to the International Space Station on June 5. But problems with helium leaks and thruster failures were subsequently discovered and have kept the astronauts in space conducting tests to determine whether the Starliner could bring them safely back to Earth.

NASA now says that it would be safer for the pair to hitch a ride back to Earth next February with SpaceX’s Crew Dragon, a blow to Starliner maker Boeing, which NASA had tapped a decade ago along with SpaceX to provide reliable transportation to and from the space station.

While the astronauts’ plight has elicited feelings of sympathy and pity, chemist and retired NASA astronaut Cady Coleman admits to feeling something different: jealousy.

Coleman, author of Sharing Space: An Astronaut’s Guide to Mission, Wonder, and Making Change, flew twice on the Space Shuttle and spent nearly six months on the International Space Station. She told Today, Explained host Sean Rameswaram that this is what astronauts dream of: more time in space. Their conversation below has been edited for length and clarity.

—Avishay Artsy, senior producer, Today, Explained

What’s space like, Cady?

I always have to take a breath and think how to say this, but it is like being transported to a different world. And I know I’m definitely still in this one same universe — look down, see Earth — but you really are at the edge, so to speak. And I felt really privileged to be one of the people who is the furthest away, meaning they’re basically the closest to everything else we haven’t seen.

And one of the things you saw when you were in space most pertinent to our conversation today was the International Space Station.

I did, and I lived up there for almost six months. I really loved it up there. But that first sight, I mean, I was so used to doing spacewalking practice in our giant swimming pool where it’s like 40 feet deep, the size of a football field. And then you arrive at this pristine city in space. It was like being in Wonderland. Suni had two missions to the space station already, this is her third. And Butch had one shuttle and then one station, and now he’s up there. So they knew what they were coming to.

It’s a magical place. And I think what’s really meaningful is knowing that everything that you do up there matters. It gets us one step closer to going back to the moon and going to Mars. And I don’t just say that like it’s a trendy thing to say, because I just think it’s true.

Do you know these two astronauts, Butch Wilmore and Suni Williams?

I do. We all know each other. It’s like one big family. I arrived in 1992, Suni and Butch just a little bit later than that. I’m a little closer to Suni than I am to Butch, just because we have a little more in common. But I’ve done a lot of training with Butch in the T-38 airplanes that we fly to learn things. He and Suni are both test pilots, and I am from the Air Force, but a chemist from the Air Force. So I had a lot to learn from each of them in terms of aviation. And Suni just has this really great attitude. Whether it’s organizing a neighborhood event or something in the astronaut office or being in this kind of situation, Suni has this very levelheaded but joyful way of living that is inspirational to me as a friend.

And so when you heard that they weren’t going to come back as early as hoped, what went through your head first?

Certainly some jealousy …

I would imagine many of us are. And at the same time, it’s certainly their time to fly again. They’ve been very patient. So it’s not like, “Oh, this could be mine.” It’s more just a little bit wistful because I really loved working up there and I think it’s a great opportunity. But I also love watching folks that I know are just really invested and wonderful working up there.

I tell people this is NASA at its very best. It is taking the time to collect test data just like they should, even though the media keeps emphasizing that the two people are stranded, when this is just the way learning more about space and your capabilities works.

You have mentioned that there’s a lot to do up there, whereas I imagine most people think they’re probably just losing their minds. What are they doing up there?

There’s a whole list of experiments and maintenance that has to be done. When we go up to space, we take away a huge variable, which is that we are basically weightless, not perfectly, but as close as you need to get to learn a lot. You get to measure things that are hard to measure on the earth. And we learn about things like combustion and about groundwater and erosion. We learn how plants grow, don’t grow. If we’re going to grow corn on Mars, we probably don’t need corn stalks because they’re not going to have to hold themselves up very much. So it’s all these different ways of thinking scientifically. It’s another laboratory. It’s almost like a brand-new microscope, a different way to look at things.

What do Butch and Suni need to do while they’re up there to make sure being in a near-zero gravity situation doesn’t take a toll on their bodies?

Exercise is the biggest answer that we’ve seen. I mean, without exercise, without some kind of countermeasure, astronauts were losing about a percent and a half of their bone mass every month.

What a woman who’s 70 years old and has osteoporosis loses in a year, I would lose in a month if I did nothing. It’s a big deal. We looked at different drugs and different kinds of exercise and exercise machines. They spend about two hours a day exercising. And about half of that is aerobic on a treadmill or a bike, keeping their hearts in shape. And about half of that is lifting weights. And we’re finding that people are coming back with most of their bone mass.

How does an astronaut on the ISS find time to, I don’t know, say, duet with Ian Anderson from Jethro Tull?

Well, in my case, I think most of the creative things that I did up there were probably done during time I was supposed to be sleeping.

We are a small part of a really big place, and we belong up there. And the feeling I had when I came home was just that I knew I’d go to space. I didn’t understand that once I got there, I’d actually feel just as close to Earth. And so it turns out that home is bigger than we thought.