Outer Space Changes You, Literally. Here's What It Does To The Human Body

Primary Topic

This episode delves into the profound effects of space on human biology, explored through scientific research and astronaut experiences.

Episode Summary

"Outer Space Changes You, Literally" is a captivating exploration of the human body's response to space environments, featuring insights from NASA astronauts and scientists. The episode discusses various physiological changes astronauts undergo in microgravity, including muscle atrophy, bone density loss, and fluid shifts that affect vision and cardiovascular health. It highlights studies conducted on the International Space Station (ISS), such as the twin study with Scott and Mark Kelly, which provides detailed observations on genetic alterations due to long-term space missions. The episode also touches on the psychological challenges of space travel, like isolation and the monotony of long missions.

Main Takeaways

  1. Microgravity causes significant physical changes, including muscle weakening and bone density loss.
  2. Fluid shifts in microgravity lead to 'moon face' and vision changes due to eye shape alterations.
  3. The closed environment of the ISS poses health risks, such as weakened immune responses and potential for virus reactivation.
  4. Psychological effects of long-duration space missions include isolation stress and sensory monotony.
  5. Advances in space health research are driven by extended ISS missions and studies involving a wider range of participants.

Episode Chapters

1. Introduction to Space Biology

Focuses on the fundamental changes to human physiology in space. Highlights astronaut Wendy Lawrence's experiences and initial recruitment into NASA.

  • Regina Barber: "When you get the call that you're going to space, it changes your life."
  • Emily Kwong: "NASA endeavors for longer missions to establish a presence on the moon, maybe put some boots on Mars."

2. The Science of Living in Space

Delves into scientific studies conducted on the ISS, particularly how astronauts' health is monitored and managed.

  • Kate Rubens: "We're studying everything from how cells grow and replicate in space to making drugs in microgravity."

3. The Impact of Microgravity on the Body

Explores specific physical changes caused by microgravity, including bone density reduction and fluid redistribution.

  • Regina Barber: "Under those conditions, muscles weaken in their weight-bearing bones."
  • Kate Rubens: "That's what it feels like in space."

4. Long-term Health Risks and Studies

Discusses long-term health risks like radiation exposure and psychological effects, supported by data from the twins study.

  • Regina Barber: "This study really pointed a compass arrow down all these research pathways."
  • Emily Kwong: "Radiation is a silent threat. The exposure to it is real bad."

5. Looking to the Future

Considers future challenges and advancements in space health research, with implications for extended missions to Mars.

  • Regina Barber: "Another all-civilian crew going up to space, the Polaris dawn mission."

Actionable Advice

  1. Exercise Regularly: Mimic astronauts who combat muscle and bone loss with rigorous daily exercise routines.
  2. Monitor Health Closely: Regular health screenings can catch issues early, akin to the medical monitoring in space.
  3. Adapt to Environments: Learn from astronauts' adaptability in closed environments to manage stress and maintain mental health.
  4. Embrace New Frontiers: Stay informed about advancements in space research to understand its impact on health.
  5. Support STEM Education: Encourage involvement in science and technology to participate in future space explorations.

About This Episode

Lower gravity. Higher radiation. No ER access. These are just a few of the challenges that humans face in outer space. Emily and Regina talk to a NASA astronaut (and astronaut scientist) about the impact of spaceflight on the human body. Plus, we learn about telomeres (hint: They change in space)!

People

Kate Rubens, Wendy Lawrence, Scott Kelly, Mark Kelly

Companies

NASA

Books

None

Guest Name(s):

None

Content Warnings:

None

Transcript

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Regina Barber
You're listening to shortwave from NPR.

Emily Kwong
Hey, short waivers. This is your captain speaking.

Regina Barber
Regina Barber and first officer Emily Kwongenhe. More than halfway through the space camp series. Can you believe that, Gina?

Emily Kwong
I can't, actually. But we've gone past Pluto. We've gone through birthing stars, contemplated the three body problem and the mysteries of dark matter and dark energy.

Regina Barber
It's been cool.

Emily Kwong
And today, Em, we're going to turn the focus inward to the existence of our species in space.

Regina Barber
That's right. Today we're talking about humans living in space. Cause let me tell you, when you get the call that you're going to space, it changes your life. After years of flying Navy helicopters, Lieutenant Commander Wendy Lawrence was teaching physics at the US Naval Academy when the phone rang.

Wendy Lawrence
I'm sitting in my office. The phone rings. I answer it. You know Lieutenant Commander Wendy Lawrence. May I help you, sir? Ma'am? Hi, Wendy. How you doing? This is Don Putty calling from the Johnson Space center immediately. I know. Ooh. This is the good phone call.

Emily Kwong
With this call, Wendy became the first active duty female naval officer selected for NASA's astronaut program, which meant Wendy couldn't tell anyone for 24 hours.

Wendy Lawrence
They told me I had to keep it a secret. It was my first official responsibility as a new astronaut candidate, and I'm not gonna screw up.

Regina Barber
Wendy did not screw it up. All told, she has gone to space on four separate missions.

Wendy Lawrence
I've flown the station arm.

I've overseen transfer operations between spacecrafts. So every mission is fun because you typically do something different.

Emily Kwong
But as NASA endeavors for longer missions to establish a presence on the moon, maybe put some boots on Mars, they've begun to study the most fragile and variable system of all the human body.

Regina Barber
And sitting pretty 250 miles above the Earth is the International Space Station, which has proven to be the perfect laboratory to analyze the hazards of spaceflight and test out possible solutions.

Kate Rubens
The majority of what we do is scientific investigations on board the space station. So we're studying everything from how do cells grow and replicate in space to making drugs with specific crystal forms in microgravity that are actually being used back on Earth for cancer patients.

Regina Barber
This is microbiologist Kate Rubens, who was hired from an infectious disease lab at MIT to become a NASA astronaut. She has spent 300 days across two missions aboard the space station doing experiments related to human health and viral disease. In many ways, her hire represents a generation of astronaut scientists building out our toolkit for space medicine.

Emily Kwong
Today on the show how our quest to live in space is opening up new doors for science. It's awe inspiring and filled with calculated risks. We talk about some of the challenges to human spaceflight and what that means for a mission to Mars. I'm Regina Barbour.

Regina Barber
And I'm Emily Kwong.

Emily Kwong
And you're listening to Space Camp, the spectacular summertime space science series from Shorewave at NPR.

Regina Barber
That was so impressive.

Emily Kwong
Thank you.

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Emily Kwong
Been looking into how spaceflight affects the human body, and when I think about this topic, I think about poop.

Regina Barber
Geno.

Wendy Lawrence
Really?

Emily Kwong
Yes. And how astronauts have to poop in microgravity in one of those two toilets aboard the ISS or in a diaper.

Wendy Lawrence
If they go on a spacewalk onboard the spacecraft. It really is all about creating suction. And generally the toilets work pretty well. And if they don't, that's really not a good day for you in space.

Emily Kwong
I so love Wendy. I love Wendy almost as much as I love talking about poop.

Regina Barber
It's one of your top passions.

Unidentified Speaker
It's true.

Emily Kwong
It is. It is. But okay, back to more serious science. When I think of humans in space. Actually, I also think about this, like, twin study.

Regina Barber
When you told me about this research, I thought it must have to do with twin galaxies or moons. But no, it's actually twin astronauts, Mark and Scott. Mark and Scott Kelly. They were the twins at the center of a year long study of astronauts. Here's them talking in a PBS documentary.

Scott Kelly
While twins are born with the same genetic material, it changes over time, and maybe it changes more rapidly in space than on Earth.

NASA is doing kind of a comparative study between my brother Mark and I, since we're identical twins.

Regina Barber
This is from a documentary about the twins. Both Mark and Scott had been to space before, but in 2015, Scott went to the International Space Station for 340 days while Mark stayed on Earth. And because of this study, we know in greater detail what happens to astronauts on long missions.

Emily Kwong
And what are some of those things?

Regina Barber
It is a long list. A lot of it has to do with the first main hazard to astronauts, which is microgravity. Under those conditions, muscles weaken in their weight bearing bones. Astronauts lose 1% of bone density a month, which they counter as best as they can with exercise. Scott also got that puffy moon face from fluids filling his upper body and head. Astronaut Kate Rubens remembers the stuffy noses, the colds.

Kate Rubens
If you want to feel this at home, you can go lay down on your bed or your couch and hang your head off the end of the bed and kind of feel all that blood rush to your brain.

Emily Kwong
Done it.

Kate Rubens
That's what it feels like in space.

Regina Barber
Except in space, Gina. It stays that way for months. This long term shift in fluids, it led to Scott's eyes changing shape, which affected his vision. His heart got rounder, too, as his blood vessels swelled and his carotid arteries started to thicken. A 2019 paper found that some astronauts on the space station experienced stagnant or reversed blood flow in their jugular vein, some of which led to clotting.

Emily Kwong
Wow. And these clots are not good, not in space and not on earth.

Regina Barber
And that's why the twins study is so valuable. I'm glad you told me about it because it really pointed a compass arrow down all of these research pathways, like one arrow screaming, look at the heart in space. So, years later, Kate, our astronaut, took part in the cardinal heart study. She helped engineer cardiovascular tissue on the space station and determine how that tissue was impacted by microgravity.

Emily Kwong
Wow. Okay, so microgravity is one hazard to spaceflight. What's another?

Regina Barber
Simply being aboard the International Space Station, which is considered a hostile, closed environment. And that is a problem the longer you're up there, because we now know space travel weakens the immune system. So Kate told me that historically it's happened that a small number of astronauts have developed these painful blisters aboard the space station. And NASA later learned it was symptomatic of shingles, a reactivation of a previously had chickenpox virus.

Kate Rubens
So things like shingles have come back for healthy adults on space station, you know, herpes virus. So we definitely don't want a crew on the way to Mars to have an issue with endogenous viruses.

Emily Kwong
So what's an endogenous virus?

Regina Barber
It's basically a sequence from a virus that hangs out in your cells in stealth mode, can reactivate. That's why paying attention to immune system responses on the space station is so important.

Astronauts are also always on the lookout for microbes. And historically, if there were some weird growths on the wall or in their water, astronauts had to go through this really complicated, months long process to figure out what it was.

Kate Rubens
We would take a little swab sample, we would streak it on a plate. We had to physically send it back to Earth. It would land in Kazakhstan. We would send some NASA people over on an airplane to get this plate and to fly it back to the lab at Johnson Space center in Houston, Texas. And then they could start their microbiology.

Regina Barber
But because of kates work, she was the first person to sequence DNA in space. Astronauts can now identify what something is in less than a day and track on these microbial communities of concern. It's just one example of how NASA is trying to give astronauts biomedical tools, which will be really important for deep flight missions someday.

Emily Kwong
Okay, so there's microgravity being in this closed, hostile environment. Let's talk about another big one, one that I know maybe a little bit more about. Radiation.

Regina Barber
Yes. I shouldn't sound so excited. Radiation is a silent threat. The exposure to it is real bad.

Emily Kwong
Yes, but I like talking about it. Right. Cause it's something that I, as a physicist, I know what it is. Right. It comes from two places. The radiation we're dealing with in space. One, the sun is sending radiation towards us from solar storms. And two, energy, galactic cosmic rays, which are like, from stuff like exploding stars in space.

Regina Barber
Yeah.

Emily Kwong
And NASA is paying attention to this because, of course, exposure to radiation is not good. It can damage your DNA.

Regina Barber
Right. Because to fix DNA, the human body makes repairs. This radiation and the repair process may increase an astronaut's risk of cancer, heart disease, nerve damage, a whole slew of other medical risks.

Emily Kwong
Yeah. And there has been, like, studies that are astronauts, like, at higher risk for this stuff, but, like, how high of a risk has been, like, the studies?

Regina Barber
Yeah, it's an interesting question because a lot of our data comes from the space station, right? But the space station is in low Earth orbit. It's not getting a ton of radiation. And not every astronaut is like Scott Kelly, who goes up there for over a year.

But in Scott's case, radiation did change his genetic materials, specifically his telomeres.

Emily Kwong
Yeah. So, telomeres, they're like the caps that protect the ends of DNA strands. This is what I've been told.

Regina Barber
Yeah, 340 days in space, as Scott Kelly's telomeres, on average got longer. And this phenomenon of telomere elongation, it was also seen in the all civilian SpaceX inspiration. Four crew that just went up after only three days in space. It's an interesting discovery, and it's borne out of a real change in the research. We are now sending a broader range of people to space. It's not just astronauts with olympic levels of training like Wendy.

It's also regular folks. Christopher Mason, a professor of genomics, physiology and biophysics at Weill Cornell Medicine, sees this as a real research opportunity.

Christopher Mason
We have a chance to study how the human body adapts to space for a wider representative group of humanity. So people that might be pre diabetic, who might have a higher risk of cardiovascular disease or maybe are a bit older, like we've seen William Shatner, for example, doing a suborbital flight.

Regina Barber
Yeah, captain. The original Captain Kirk.

Emily Kwong
Yeah.

Regina Barber
And he's doing okay, I guess. I mean, this is all, at least to Chris, creating a second space age, but with more widely available data, a more engaged research community. And just like the tent poles of a future where more people are prepared for spaceflight.

Christopher Mason
And this is what we'll need to understand to really enable people to live and work in space.

Regina Barber
There's actually Gina, another all civilian crew going up to space, the Polaris dawn mission. And they will be continuing some of the biomedical research that was done on the inspiration for mission.

Emily Kwong
That's really cool, but I want to go back to where we started, actually, especially with longer space missions and the idea of people being on the moon or, like, living on Mars, besides radiation, microgravity, and being in this closed, hostile environment. I think we have time for one more issue. What else are NASA scientists keeping tabs on?

Regina Barber
This one, to me, is the most fascinating is isolation confinement. The space station is big, except for.

Kate Rubens
You'Re going to seal and lock the doors. Nobody in, nobody out.

Regina Barber
So Kate Rubin says that NASA is screening for astronauts differently these days. They're looking for people who can handle what is essentially six months of camping in an environment that wants to kill you.

Emily Kwong
I can't do a day I bet you could hang.

Regina Barber
Because when you get the call, you really have to cultivate certain interpersonal qualities. The ability to lead, but also the ability to follow, to get along with people who are different from you, and to remember what this is all for.

Kate told me a story that I've been thinking about towards the end of her last mission. She got out of bed one morning and couldn't escape just the monotony of the view.

Kate Rubens
And I was looking down at all this equipment and supplies, and I was thinking, I've seen this every single day of my life for the last, like, 160 days. And it's only a few feet. And I go the same route, you know, I do the same handrails. And so it's like, man, I just don't want to look at this same stuff anymore. So I went over to the windows, I looked down at the earth, and we were flying over this incredible kind of view of the great Lakes. And you can see the sunlight reflecting off the water.

Emily Kwong
Oh, that's beautiful.

Kate Rubens
And that really quickly got me out of my complaining about tracking over the same area of the space station over and over again.

Regina Barber
Astronauts like Kate and all of the ground support they receive have contributed to discoveries that have transformed life on Earth.

Emily Kwong
Right?

Regina Barber
I mean, the Apollo program gave us the technology that ultimately went on to power our cell phones. Breast cancer screenings were made better by NASA algorithms. I mean, astronauts may be miles from Earth, but our relationship to them and their relationship to us is constant. Kate was really reminded of this every time she got mail from home.

Kate Rubens
We have the opportunity to send little care packages to space. Let me tell you, when you're having a bad day and the toilet's broken for the third time, it's the toilet again. Experiment's not going right, and you've been in the space for four months, and you're a little bit itchy. Cause you got a rash from some of this immune stuff that's going on. A letter from mom goes a long way.

Emily Kwong
Speaking of letters, M, we're gonna be flying by a black hole next week, and we have a letter for you from our next expert.

Priya Natarajan
Hey, short waivers.

It's Priya Natarajan, your commander of Terra Firma, speaking.

I gather you've left us and are hurtling beyond the solar system. Approaching the potential black hole binary near us. OJ 287 be careful. Don't get too close. Spaghettification near a black hole is no joke.

Emily Kwong
Before we head out, a reminder that we'll be back tomorrow with our regular shortwave and back Tuesday with another episode of our summer Space Camp series.

This episode was produced by Hannah Chin and fact checked by Emily Kwong. It was edited by our showrunner Rebecca Ramirez, and it was engineered by Robert Rodriguez. Julia Carney is our space camp project manager, Beth Donovan is our senior director, and Colin Campbell is our senior vice president of podcasting strategy. Special thanks to our friends at the US Space and Rocket center, home of Space camp. I'm Regina Barber.

Regina Barber
And I'm Emily Kwong, and you're listening.

Emily Kwong
To short wave from NPR.

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