This pressurized, skirt-like machine helps keep astronauts fit

Apr 29, 2017

Many engineers spend their entire careers focused on a single area of research — say, the design of airplane components. Then there's Christine Dailey: Put simply, she's not your average engineer. 

Dailey has explored everything from fluids to electronics and has built an exercise machine for astronauts. She has designed autonomous vehicles and much more (some of which she's not allowed to talk about), all while finishing her PhD at Embry-Riddle Aeronautical University and working as a mechanical engineer for the Naval Research Laboratory in Washington, DC.

But Dailey wasn’t always sure she wanted to be a mechanical engineer. In fact, her first idea was to become a sports journalist. However, she found it a little repetitive. “After about five or six years, one team wins, one team loses,” she says, laughing. So she made plans to go back to school. “I happened to be kind of good at math, so I fell into it.”

Then, she says, she “fell right into the robotics lab” on her tour of Embry-Riddle. For her master’s project, Dailey tackled the problem of exercising in space.

As she explains it, astronauts have to use an array of machines to counteract the negative effects of zero gravity. “We have orthostatic intolerance, for example, bone loss, muscle loss. And so exercising is proven to one, create plasma ... red blood cells live in plasma, and red blood cells help move oxygen through the body.”

What’s more, Earth’s gravity creates natural resistance on our bodies. “So you’re exercising without even knowing it,” she says. But in zero gravity, our bones don’t have much to support. “So they don't need to be strong.”

Currently, it takes three separate machines — and a lot of time — for astronauts to counter the effects of space on their bodies. “It's a treadmill, and then a bicycle-type thing, and then a resistance device they call RED,” she says. “And [astronauts] have to split up their time, about two and a half hours a day, working on these machines.”

Therein, Dailey saw a problem. “Well, that's not really ideal,” she says. “I'm sorry, if I'm an astronaut, I don't want to spend two and a half hours a day exercising. I want to go explore. I want to go float around and have fun.”

So she built an “elliptical-type” exercise machine, housed in a negative pressure chamber. She explains that the waist-down chamber — which looks a bit like an enclosed, space-age hoop skirt — mimics the effect of gravity on our blood and other fluids, pulling them down toward our feet.

“So you're pulling the fluid down, and you're exercising,” she says. “You get the resistance for your muscle, you get the pressure for your bones. It's wonderful.”

This article is based on an interview that aired on PRI's Science Friday, as part of a special live show on “Engineering the Future” at the Bob Carr Theater in Orlando, Florida.


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