Catherine “Cady” Coleman is a chemist, former Air Force officer, flute player, scuba diver, and astronaut. And most recently: Hollywood adviser. In 2011, while serving 159 days aboard the International Space Station (ISS), Coleman spoke with actress Sandra Bullock, helping Bullock parse her role as a newbie astronaut destined for disaster in the dizzying new space thriller Gravity, opening tomorrow. The film sets Bullock’s character adrift in space after a catastrophic collision with space debris destroys her shuttle.
In a recent interview with ScienceInsider, Coleman said her days in space were, by design, never as eventful as in the movies. But for her, Gravity captures the essence of life 400 kilometers above Earth. The interview has been edited for clarity and length.
Q: What questions did Bullock ask you? What did she want to know?
C.C.: We talked about a lot of different things … how you moved and how you kept yourself in one place. We have handrails all over the station, like the monkey bars. You can be flying along, and then just hook your feet into one of these and stop. I came back with literally no calluses on my feet—they were like baby feet. Except on the tops of my feet, I had calluses from sliding under those bars. The other thing that we talked about was the emotional component of living someplace dangerous, and a place where you can be truly alone. How to live with that.
Q: How do you deal with those challenges?
C.C.: I have to compartmentalize a little bit, and put that sadness and grief I feel about not going on the zoo field trip with my first-grader in a special place, and not let it interfere with the important job that I’m doing. … That part of it is really challenging and hard, and this movie really brings that home to me. It was certainly a very emotional movie for me to watch.
Q: You’ve been on two shuttle missions and you’ve lived on board the ISS. How realistic is the movie?
C.C.: There’s a lot of things that [the film does] really, really, really nicely that make it almost an IMAX movie about being in space. I feel very lucky to have this job, but I don’t get to bring my friends and family with me. They have, to me, documented the look and the feel of living in low-Earth orbit, and that feeling of both isolation and the specialness of having a view that not many people get to have. At the same time, there are a lot of things [in the movie] that aren’t realistic. There are a lot of coincidences—each of them are perhaps possible—but it’s not probable that they would all happen on the same day, at the same time, or in the same order.
Q: I’m assuming there are a lot of safety protocols to prevent astronauts from hurtling off into space.
C.C.: It is physically possible, but we work really hard to make sure that doesn’t happen. We are tethered at all times during our space walks. We’re always connected by a retractable dog leash that can stretch out to be about 84 feet [25 meters] long. …Then we do an additional thing called a local tether, made of Kevlar, and it’s always hooked to you. As soon as you get somewhere [on a space walk] where you want to work, the first thing you do is reach out with your local tether and tether yourself.
We train for that really, really hard. In the [training] pool, if at any time I go to a work site and I’m not either holding on or using my local tether, the divers will actually drag me 4 feet [1.2 meters] off the [mockup] station so it’s really clear, to me and to everyone else, that I let go—it’s actually embarrassing! That’s how serious it is. Having said all that, there are some pretty violent things that happen in the movie and I don’t know if those tethers would hold.
Q: What happens if the tethers fail?
C.C.: We do have a jetpack, but it’s not the one you see in the movie, [which is] modeled after one that we used to use. … But it ended up being not very practical, partly because there was no tethering [with that pack]. … [Now we wear] a new one, we call it SAFER, and its function is different. It’s just a rescue pack. If for some reason both of your leashes fail, you’d probably find yourself spinning, and then you just push a button, and that jetpack has a gyroscope that will sense where it is and stop itself from spinning. Once you’re stable, you’ll use your hand controller to turn yourself around, see where the station is, and fly back.
Q: What about space debris?
C.C.: The reason NASA doesn’t make documentaries that keep people in their seats is because each of the risks in this movie is real, but we work really hard to mitigate those risks. There’s a team in Colorado that tracks every piece of orbital debris over half an inch. It was actually fascinating for me to come back to Houston after Hollywood and be right in the middle of the arrival of the newest supply ship to the space station. What’s the first thing we have to deal with? There’s a piece of space junk in the way between that new supply ship and the space station. It just proves the point that these things are real for us, but we actually know how to deal with them.
Q: So how big of an issue is space debris for NASA and the space station?
C.C.: Space debris is an issue that we track every minute of every day. We track the debris and we can see when it’s coming within about a week. And we can certainly move the station—if we have time and we have enough fuel. Sometimes things appear more quickly and we don’t have time. [Light debris] is harder to track than something very solid that’s going to have a very even and constant trajectory. In that case, if we can’t be certain if debris is going to hit or not, and it’s too late to move the space station in time, we will actually wake the crew up if necessary, and have them be in their supply ships with the hatch closed, ready to undock from the station.
Q: Is there anything you felt compelled to impart to make sure that Bullock understood a little bit of what it’s like to be up there?
C.C.: Something that’s really hard for me to communicate is the physical beauty, and just the bigness of the picture. Looking down at the Earth, it’s very difficult for me now to think of myself as a citizen of just one country. I can’t help but feel like an inhabitant of the Earth. The physical beauty of just looking down at our planet makes it clear to me that our planet is just one house in the neighborhood. Everyone on our planet is a space traveler.
Q: What was the most unexpected thing about life on the station?
C.C.: Living in space is not so much about floating as it is about flying. For us down here on Earth, even flying in an airplane is pretty neat—it just seems like something people aren’t supposed to do, we don’t have wings! But flying without an airplane? Giving yourself a push with your little finger and flying across the long, extended hallway of an enormous space station? I miss that magical feeling. It is like living the life of Peter Pan. You wake up every day and you’re still living it. What’s magic about that is if that’s happening, what are the as-yet undiscovered possibilities of what we as humans can do?