Do Astronauts Float Around While They Sleep?

Summary

Podcast Summary: Chasing Life – "Do Astronauts Float Around While They Sleep?"

Host: Dr. Sanjay Gupta
Date: April 14, 2026
Episode Theme: Special Artemis 2 Edition—Exploring astronaut health in deep space, questions from listeners, and the science behind human survival, sleep, and thriving aboard NASA’s latest mission to the moon.

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Episode Overview

In this Artemis 2 special edition, neurosurgeon and journalist Dr. Sanjay Gupta answers pressing listener questions about astronaut health, inspired by the recent successful moon mission. The episode delves into how NASA protects astronaut well-being in space, explores unique challenges of the microgravity environment, and reveals quirky facts about astronaut life—including what they actually eat (and why hot sauce matters). Dr. Gupta is joined by Kira, who reads listener questions, including some from very young fans.

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Key Discussion Points & Insights

1. Major Health Concerns for Astronauts: The "RIDGE" Framework

[02:03]

• RIDGE stands for Radiation, Isolation, Distance from Earth, Gravity, and Environment.
• Each element represents a unique risk to astronaut health that NASA monitors and tries to mitigate.

Gravity:

• Microgravity affects bodies in surprising ways:
  • Muscle and bone loss: Both diminish quickly in space.
  • Fluid shift: Body fluids migrate to the head, causing puffy faces and side effects like headaches and changes in vision.
  • Taste changes: Astronauts often find food blander; "NASA sends up five different types of hot sauces" to counteract this ([03:19], Dr. Gupta).
• Daily exercise is essential:
  • New "Artemis flywheel" exercise device (size of a carry-on suitcase) used for aerobic, resistance, and row training ([03:41]).

Radiation:

• Exposure to solar and cosmic radiation is a big unknown, especially outside Earth's magnetosphere.
  • "Each of the crew members is also wearing a dosimeter in their pocket... the first time they're being used beyond Earth's orbit." ([05:36], Dr. Gupta)
  • Dosimeters and sensors track exposure to warn of solar flares.

Isolation & Distance from Earth:

• Living/quarantine in a tight Orion module (studio apartment-sized vs. the "six-bedroom house" of the ISS).
  • Monitors track astronaut mobility and sleep.
  • NASA studies team dynamics and mental health, especially with delays in Earth communication (3-14 seconds to the Moon vs. 44 minutes roundtrip to Mars) ([06:46]).

Immune System & Viral Reactivation:

• Saliva test with filter paper collects daily samples to track changes in hormones and immune function.
• Viral DNA can reactivate in space, potentially spreading among crew due to immune suppression.

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2. Q&A Highlights—Listener Questions Answered

A. Astronaut Sleep: Schedules and Science

[08:27]

• Astronauts do not "just float around"—they sleep secured in bags attached to the Orion's wall.
• Early on, sleep was fragmented by mission-critical tasks; later switched to eight-hour blocks.
• Microgravity, noise, vibration, and disrupted circadian rhythms make sleep a challenge.
  • "Astronauts commonly experience sleep deprivation during spaceflight. Noise, temperature, vibration, light—these things are amplified up in space." ([08:53], Dr. Gupta)
• NASA monitors sleep with special wristbands, aiming to optimize cognitive performance.

B. Hydration in Space: How Astronauts Get Enough Water

[10:34]

• Four tanks, each with 125 lbs of water, launched with the crew.
• Water is rationed for both drinking and food rehydration.
  • Dehydration as slight as "a couple percent" can harm decision-making and performance ([10:47]).

C. The Disappearing Taste Buds—and the Hot Sauce Fix

[11:47]

• Five types of hot sauce fly with every Artemis crew!
  • "Out of all the things you send to space, hot sauce ends up being a really important one." ([11:58], Dr. Gupta)
• Microgravity affects taste through direct impact on taste buds and increased sinus congestion.
  • "Astronauts tend to crave a little bit more spicy foods in space." ([12:34])
• Menu highlights: tortillas (58 went up!), wheat flatbread, vegetable quiche, couscous with nuts, and breakfast sausage—all in heat-stabilized pouches.

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Notable Quotes & Memorable Moments

• Dr. Sanjay Gupta, on NASA's health concerns:

  "Of course they have an acronym for what they’re worried about. And that acronym is RIDGE: Radiation, Isolation, Distance from Earth, Gravity, and Environment." ([02:23])

• On sleep deprivation in space:

  “Noise, temperature, vibration, light—we know all those things can inhibit sleep. And a lot of those things are amplified when you’re up in space.” (Dr. Gupta, [08:53])

• On hot sauce in orbit:

  “Out of all the things you send to space, hot sauce ends up being a really important one. Why? Turns out microgravity can diminish the astronaut’s ability to taste.” (Dr. Gupta, [11:58])

• Describing the Orion module:

  “The Orion spacecraft module… has habitable space about the size of a studio apartment. It’s much smaller than the International Space Station—that is basically a six-bedroom house.” (Dr. Gupta, [06:27])

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Timestamps for Key Segments

• [00:55] — Top NASA health concerns for Artemis astronauts
• [02:03] — The RIDGE acronym explained
• [04:45] — Effects of microgravity: muscle, bone, fluids, and taste
• [05:36] — Radiation hazards and monitoring beyond Earth
• [06:27] — Life in tight quarters: isolation, team dynamics
• [08:27] — Listener questions about sleep in space
• [08:53] — Sleep deprivation, circadian issues
• [10:34] — Water logistics and hydration
• [11:47] — The mystery of hot sauce and palate changes in space

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Tone & Style

• Friendly, curious, and accessible science communication, with a dose of childlike wonder (reflecting the audience’s questions, including those from children).
• Dr. Gupta conveys both admiration and deep attention to scientific detail, making complex issues relatable with anecdotes and vivid examples.

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Conclusion

This episode of Chasing Life takes listeners inside the Artemis 2 mission, breaking down the ingenious—and sometimes surprising—measures NASA takes to keep astronauts healthy beyond Earth. From high-tech exercise gear to hot sauce pouches, every detail is scrutinized to protect crew well-being. Dr. Gupta’s engaging explanations make the marvels and challenges of astronaut life feel close—and answer just what it takes to sleep soundly while floating around the moon.

Transcript

[Dr. Sanjay Gupta]

Hey there. Welcome to Paging Dr. Gupta. Thank you so much for joining us. This has become a real community. People calling in, writing in. I love hearing from you. I love hearing your health questions. So this week we're going to do a special Artemis 2 edition of the show. Think of it as a helmet tip to the four pioneering crew members. They returned to Earth April 10th last week after a 10 day mission to the far side of the moon and back. Now, you might know I'm a huge fan of space. I'm a huge fan of the science behind keeping humans healthy as they journey beyond our planet. And apparently, judging from all the questions you've been sending in, many of you are as well. So let's blast off. Let's not delay. Okay, Kira is back with us. What's our first question?

[Kira]

You know, Sanjay, I too am a bit of a space enthusiast and the whole time watching the Artemis 2 mission live streamed, I was just so curious. You know, from a health perspective, what is NASA most concerned about when it comes to the crew?

[Dr. Sanjay Gupta]

Well, this is a great question and the short answer is Ridge R I D G E. I'm going to tell you what that stands for after this short break.

[Kira]

Pepsi Prebiotic Cola in original and cherry vanilla, that Pepsi taste you love with no artificial sweeteners and 3 grams of prebiotic fiber. Pepsi Prebiotic Cola. Unbelievably Pepsi.

[Dr. Sanjay Gupta]

All right, welcome back to paging Dr. Gupta. Today we are answering questions about the Artemis 2 mission. So amazing how many people are interested in this. First up, what types of health issues is NASA most worried about? Well, it's NASA, so of course they have an acronym for what they're worried about. And the acronym is Ridge Radiation Isolation Distance from Earth, Gravity and Environment. And let me tell you something, they get very granular about all these various topics. So if you think about all of these buckets of potential concerns, we can start to address a few of them. So gravity, for example, the minimal gravity conditions, there's lots of things that happen. Your muscle mass, your bone mass, those can both be affected. Those can both be diminished pretty quickly. In a microgravity environment, the fluid in your lower body that starts to migrate toward the head, that can leave the faces of the astronauts looking kind of puffy. If you look at images of those astronauts in space, they often look different than those same astronauts do back on Earth. That's because of that fluid migration. But to get even more specific, as that fluid migrates, all sorts of other things happen. For example, people may develop headaches as a result of the congestion, their eyes may start to change shape. So when they look at the bright moon, for example, and then look back inside the capsule, things may be hard to acclimate. Their taste buds may change. We learned that from one of the NASA doctors. It's part of the reason that NASA sends up five different types of hot sauces up to the capsule as well. Now, one thing I will tell you is that the members of the crew, they do complete daily exercises. They're testing it out on a brand new Artemis flywheel. It's an exercise contraption that's about the size of a carry on suitcase. They can do aerobic, resistive and rowing exercises. Bicep curls, bent over rows, deadlifts, squats, calf raises again. This can help with the muscle mass, the bone density, and also to help recalibrate the fluids in the body. NASA is also trying to answer some very specific health questions. So every day when the astronauts wake up, before they brush their teeth or they exercise, they take a saliva test. This is essentially filter paper, which they put on their tongue. The saliva absorbs into it. Then they fold it up, put it in their pockets and bring it home. When they get home, NASA can look at those pieces of paper and they can find hormone levels and biomarkers looking for changes in immunity. They can even see whether or not viral DNA has been reactivated. This is kind of a fascinating issue. There's a theory that in a microgravity environment, viral DNA, perhaps from a previous viral infection, can actually be reactivated, potentially causing infection and potentially spreading, and again, potentially spreading to other astronauts whose own immunity may be impacted by the microgravity environment. It's fascinating. It's NASA. They get really detailed about these kinds of things. And by the way, they've actually seen viral DNA reactivation on the International Space Station. So NASA is now interested in seeing what happens with Artemis. And as they go further and further into deep space, Another thing they're studying is the R from Ridge radiation. You know, radiation is emitted from the sun. Then there's also cosmic radiation from the galaxy. The question is, what are the effects on the brain, the cardiovascular system, the immune function? We were just talking about cancer, bone marrow. So what they're doing is they're putting radiation sensors throughout the crew module. And each of the crew members also wearing a dosimeter in their pocket. This is now the first time they're being used beyond Earth's orbit. They're hoping that the data can warn the crew if perhaps they need to build a shelter to protect from radiation caused by Space weather events made by the sun, such as a solar flare. Another thing being looked at is the impact that deep space travel has on the mind. I just want you to picture this for a second. The Orion spacecraft module that the four crew members of the Artemis 2 mission are traveling in has habitable space about the size of a studio apartment. It's much smaller than the International Space Station. That is basically a six bedroom house with six sleeping quarters, two bathrooms and a gym. These four astronauts are sleeping, eating, exercising, and everything else in very tight quarters. And the reason this is important is because future deep spaceflight missions are very likely to occur in crafts of this size as well. So another study is monitoring how the crew functions, lives and works in a very confined space. The astronauts wear these trackers that are monitoring their movement and their sleep in real time. What NASA will do is combine this information with cognitive and team dynamic data to understand how, how close quarters, really close quarters affect health, safety and performance. And this will give a glimpse into when the mission is longer and even further away. For example, communication. It takes about 3 to 14 seconds, one way to communicate from Earth to the moon. When you do Earth to Mars, it's 44 minutes round trip. So understanding how astronauts handle that sort of isolation will be very, very important. So many questions about Artemis 2. We'll try and get to more of them right after this break.

[Audie Cornish]

This week on the Assignment with me, Audie Cornish. I'm talking with Jessica Gross. What do you consider the manosphere?

[Kira]

It is a loose collective of podcasters, streamers, social media personalities who tend to especially spouse conservative views on gender roles. And there's a broad range of people that you could categorize as part of the manosphere. I don't think any of them self identify that way, I was about to

[Audie Cornish]

say, because there's some progressive dudes that I consider part of the manosphere because my definition is so poor. My definition is like, do you have a podcast? Listen to the assignment with me, Audie Cornish. Streaming now on your favorite podcast, Apple.

[Dr. Sanjay Gupta]

All right, welcome back to paging Dr. Gupta. Who do we have next?

[Kira]

Yeah, so next up we actually have a few questions about sleep. So a grandma in Canada wrote in on behalf of her seven year old grandson, Cammie, asking about astronauts schedules and whether they're actually able to feel rested during a mission. And then we also had Malachi from, from Florida who was wondering what sleep even looks like in space, especially when you're floating the whole time.

[Dr. Sanjay Gupta]

All right, I love that 7 year old Cami's grandmother Writing in. First of all, Kami, you're right. We all need to be well rested so we can perform at our peak. Now, I will tell you, astronauts commonly experience sleep deprivation during spaceflight. Noise, temperature, vibration, light, we know all those things can inhibit sleep. And a lot of those things are amplified when you're up in space. Also, circadian disturbances are present, the day, night cycle that can be all jumbled up. These aspects can lead to fatigue and can lead to errors while performing tasks. So this is very important. NASA wants these astronauts to maintain a high level of cognition during every phase of the mission. So they got to catch shut eye. That's a really important part of the mission. But they weren't just floating around. They slept in sleeping bags attached to the wall of the Orion. And all four crew members slept at the same time. Early in the mission. We know sleep was broken up into shorter chunks due to mission critical events that the astronauts had to handle. But once the spacecraft was on a stable trajectory, the crew transitioned to a regular sleep schedule of about eight hour blocks. NASA is very interested in how the crew sleeps in deep space, and they're doing a study. So the crew members had these wristband devices that record their sleep and their movements very closely. You gotta believe that the crew probably feels a little bit like Cami. NASA's telling them when to go to bed and when to wake up. All right, what other questions do we have about deep space?

[Kira]

So our next question is coming from Brenda in New Jersey, and she's wondering, since water is so heavy, how do astronauts actually get enough of it up there? And how do they properly stay hydrated over the course of the mission?

[Dr. Sanjay Gupta]

Yeah, as Brenda knows, water is obviously essential. NASA knows it too. Here's what the agency says specifically. Being well hydrated during operations is absolutely critical, as dehydration can result in decrements in decision making, concentration, and physiology of the crew. And I can tell you that even a small amount of dehydration, just a couple of percent, can actually lead to a measurable decrease in cognitive function. So NASA rocketed the water up to space with the astronauts and everything else. There are four water tanks, each containing about 125 pounds of water. Each tank, then is connected to two water lines that lead to a potable water dispenser in the crew module. And it's not just for drinking. Sometimes that water is used to rehydrate the food as well. So a lot of the food goes up dry and then gets hydrated up in space with the same water. Okay, I think we have time for one more question.

[Kira]

All right, Sanjay, last up, we've got a bit of a spicy one. Nosa from Texas wants you to explain about the hot sauce to help the astronauts taste.

[Dr. Sanjay Gupta]

Yes, this has become a very, very popular topic of discussion. According to NASA, there are five different hot sauces flying around the moon with the crew. It's kind of incredible. Out of all the things you send to space, hot sauce ends up being a really important one. Why? Turns out microgravity is can diminish the astronaut's ability to taste. Part of it is a direct impact on taste buds. Another part of it is probably significant congestion in the sinuses and the nose which impedes the ability to smell. And we know a large part of taste is actually your ability to smell. So fluids in the body get affected by reduced gravity conditions as we've already talked about. And because of the impact on taste buds and your overall sinuses, the astronauts tend to crave a little bit more spicy foods in space. I will tell you, the Artemis crew did a food test in 2023 where they got to try various foods and then pick the ones that they took with them on their mission. NASA produces heat stabilized food in pouches similar to something known as MREs, Meals Ready to eat, which are often used by the military. These are specially designed to support the new nutritional needs of astronauts in space. Most common food items include tortillas. They started off with 58 tortillas on the spacecraft. Also wheat, flat bread, vegetable quiche, breakfast sausage, couscous with nuts, and again some foods where you probably want a little hot sauce. It's fascinating. I love everything about space and there's so much to learn from a health perspective and there's so many things to do to keep these astronauts safe. That's all the time we have for today's special Artemis 2 edition of Paging Dr. Gupta. Thanks to everyone who sent in the questions. Please keep them coming because your voice is what brings this show to life. If there's something health related you've been wondering about, send it to us. We might answer it next week. Record a voice memo and email it to pagingdrgupta.com that's pagingdrgupta.com or give us a call 470-396-0832 and leave a message. Influential journalist Kara Swisher is taking a hard look at the longevity industry.

[Kira]

There's so much bad information that the

[Dr. Sanjay Gupta]

really good information gets drowned. The new CNN original series. Kara Swisher wants to live forever now streaming on the CNN app.