This month, NASA revealed new details of the plan to send humans to Mars by 2030. It's an elaborate and expensive mission, involving a giant deep-space rocket, and roping an asteroid into the moon's orbit to use as a stepping stone to Mars.
But there are still some serious questions about a manned expedition to Mars. Namely, is it safe? That's where astronauts Scott and Mark Kelly come in. The Kelly brothers are identical twins, and the only siblings ever to both fly in space.
Starting next March, Scott Kelly will spend a year at the International Space Station. While he's up there, he will be a part of some novel scientific experiments comparing his health to his brother's down on Earth.
The idea is to learn about the effects of long-term space travel on the human body, which will influence how NASA proceeds with the Mars mission and other space travel initiatives.
The twins are ideal candidates for studying how these extended trips can affect genetics.
"It was kind of ironic or interesting — maybe serendipitous — that after this flight I will have flown about 540 days compared to [Mark's] 54, so an order of magnitude more," Scott tells NPR's Eric Westervelt.
It's known that being in space can affect bone and muscle mass, and the exposure to radiation can increase the risk of cancer. The astronauts hope this experiment will also shed light on how space travel affects the immune system. In one test, NASA says, both brothers will be given a flu vaccine to see how their systems react.
While there are a number of possible health issues associated with being in space, Scott will also be exercising a lot while he's up there (and that might encourage Mark, who is now retired, to run an extra mile or two in the meantime).
The details of the experiments haven't been finalized yet, but they will likely include drawing blood, ultrasounds, CT scans and urine samples.
"The kids usually get a little laugh out of Dad's pee being in the refrigerator," Mark says.
After 15 years of being a NASA astronaut, he says, "I've had a lot of science done on me already, so I kind of know what I'm getting myself into."
ERIC WESTERVELT, HOST:
If you're just joining us, this is ALL THINGS CONSIDERED from NPR West. I'm Eric Westervelt.
SCOTT KELLY: I listened to that in space when I was exercising, ALL THINGS CONSIDERED.
WESTERVELT: You did?
WESTERVELT: That's Astronaut Scott Kelly.
KELLY: Yeah, when I was doing the resistive, like the weight lifting, it was good, you know, to listen to NPR. Although I don't listen to NPR on Earth much just because I don't know what channel it's on.
WESTERVELT: Wait. Well, let me get that straight. You could find us at the International Space Station but you can't find us on terra firma. OK.
KELLY: Yeah, it's easy to find in space because they send it up to you directly so...
WESTERVELT: That's bizarre.
Beginning next March, Scott will be at the International Space Station for an entire year. While he's up there, he'll be part of some novel experiments with his brother Mark. Mark's also an astronaut and also Scott's identical twin. Scott Kelly and Mark Kelly, welcome to the program. Thanks for coming in.
SCOTT AND MARK KELLY: Oh, it's great to be here. Thank you.
WESTERVELT: It's tough on the radio. Listeners can't really see you but you guys are identical twins. What do you look like? Tell us. Mark, you go first.
MARK KELLY: What do we look like? Well, I look like him and he looks like me. You know, two regular guys from New Jersey.
KELLY: ...that are about 50 years old.
WESTERVELT: Middle-aged guys?
KELLY: Well, you know, you could characterize it as that but, you know, 50's the new 30, right? That's what people tell me.
WESTERVELT: Where did this idea come from to test whether identical siblings remain the same if one's in space and the other's on the ground?
KELLY: When I was assigned to this flight, we were getting ready to announce it at a press conference. And I was given a briefing from the science people on the type of science we would be doing and looking at on this one-year flight. And I asked them if someone was to ask the question about doing some kind of comparative studies between my brother and I, considering that, I mean, it was kind of ironic or interesting, maybe serendipitous that after this flight I will have flown about 540 days compared to his 54, so an order of magnitude more. And they came to the conclusion that there was merit in this in doing this type of investigation that is mostly based on our genetics and the affect on our genetics from long-duration space flight.
WESTERVELT: Mark, you'll be on the ground. You've arguably got the easier part of this. What will your day-to-day life be like in terms of these experiments while Scott's in space? Will you have to do daily, weekly monitoring and tests?
KELLY: Well, that we don't know yet. You know, I did ask NASA to try to, you know, pull some of these studies together, right? So if you need - you know, if they need to draw blood for one study, let's do that on the same day for the others. You know, the same thing with stuff like urine samples and ultrasounds and maybe a CT scan.
As a NASA astronaut over, you know, a 15-year period, had a lot of science done on me already. So I kind of know what I'm getting myself into. Something might include doing a 24-hour urine sample, Which means you're carrying a bucket around with you essentially.
WESTERVELT: That'll be interesting at barbecues.
KELLY: Yeah, yeah, it is. It's interesting at barbecues. The kids usually get, you know, a little laugh out of, you know, dad's pee being in the refrigerator.
KELLY: So there are things like that, but I don't have a schedule yet.
WESTERVELT: Researchers, as I understand it, already know a little bit that the human immune system changes a lot in space. I mean, which of you do you think will be healthier at the end of the year? Scott?
KELLY: Good question. You know, there's a lot of impacts and effects on the human body due to long-duration space flight. You lose bone and muscle mass...
KELLY: Yeah, his bones are going to turn to dust in a year.
KELLY: And you get radiation that could, you know, increase your risk of fatal cancer over your lifetime. As far as overall health, you exercise a lot, so that's a plus. But, you know, there's also those unknowns about your immune system. So it's - you know, that's what we're hoping to learn.
WESTERVELT: And are you guys going to be competitive about this at all, like Mark, maybe you'll exercise more and avoid a few cheeseburgers just to try to beat Scott?
KELLY: Well, yeah, maybe. You never know. I mean, you know. Yeah, I'll be working out twice a day I think, or two hours a day, six days a week. So maybe it'll motivate me a little bit.
WESTERVELT: Scott Kelly and Mark Kelly are both astronauts. They're also identical twins. The brothers Kelly, thanks very much.
KELLY: Oh, you're welcome.
KELLY: Yeah, thank you, my pleasure.
(SOUNDBITE OF MUSIC)
WESTERVELT: Coming up, long lost recordings from 1969 finally see the light of day. Legendary record producer Lou Adler once scoured the Baptist churches in South Central L.A. to find the soul of Bob Dylan.
LOU ADLER: I would go to church not to pray but to listen to the music.
(SOUNDBITE OF MUSIC)
WESTERVELT: The story behind Dylan's Gospel in the next part of ALL THINGS CONSIDERED from NPR News. Transcript provided by NPR, Copyright NPR.