Issue link: https://tmcpulse.uberflip.com/i/1138339
14 t m c » p u l s e | j u ly 2 0 1 9 He said, 'I have a kid who says he wants to be an astronaut. What should he do?' I was told to figure out the biggest issue NASA has to solve about life in space and become an expert in it. That's exactly what I did. What I found is that bone loss was huge. We lose 1 percent of our bone per month in space. It continues at the same rate, and at some point, we'll reach the fracture threshold—where if you step out onto a planet, and you have less bone, you'll fracture. NASA asked me to lead what's called the countermeasure effort. It was part of the medical system being developed as we were thinking about spending longer and longer periods in space. In space, your heart shrinks in size. We lose one-fifth our blood volume. We can't fight illnesses like we do on Earth. And we know genetic abnormalities occur from being exposed to zero gravity and probably radiation. The list goes on. That whole thing is called space adapta- tion syndrome. Q | Is that still the biggest challenge in getting to Mars? A | It is. Right now, it takes about a year to get to Mars, maybe three months on the surface, and maybe a year and a half to get back. There are some technologies that can get us there faster, but it's a long trip. If you don't exercise or have some way to stress the bone, you're going to end up landing with weaker bones and nobody really knows what would happen there. The other big thing with that sort of trip is radiation exposure. Any time during a trip there can be a solar flare, and if there is, then there would be a lot of issues with the crew— possibly even death from the solar flares if we aren't shielded. Q | I read that you didn't make the cut the first time you applied to be an astronaut. What was it like getting that rejection, after you devoted your entire life to becoming an astronaut? A | I was working at NASA's Ames Research Center in California at the time. I didn't make the cut, but they offered me a job at Johnson Space Center in the bone lab. They saw something in me, and that was their way of keeping me hooked. C M Y CM MY CY CMY K Houston TMC Pulse_ad_6_2019.pdf 1 6/20/19 11:17 AM But it was a double-edged sword. I could come to JSC, and if I did really well they'd hire me [as an astronaut]. But if I didn't do well … you're under the microscope. I have to say I worked hard during that period to make a name for myself. In the next astronaut class, I was the first person interviewed and the first person called and hired. Q | You went to space in 1993 and 1995, for a total of 18 days. Almost 25 years later, how often do you think about those 18 days? A | Every day. That's in part because when people find out I'm an astronaut, everybody wants to know about it. Our communications group put together what they call a post-flight video. We would play it before going onstage at speaking engagements. They'd open with us walking to the launch pad. When I saw it, it was almost like I didn't believe it was me walking to the launch pad. The experience is overwhelming; your mind cannot take it all in when you're in the moment. Q | Would you want to go back to space? A | Yes. It would be fun. I would enjoy it. If we were to go to the moon and NASA said, Spotlight