MS

Mark Shelhamer

Things Mark Says on Podcasts

Where to Find Them

Mark Shelhamer has been a guest on Blue Dot .

Recently: “Blue Dot: Can the human body survive the long trip to Mars?” on Blue Dot (October 2026).

What They Said

“It's like, I would say it's borderline criminal in the sense that there is the potential for us on the research side to be missing important information because of this incomplete data sharing… It seems that every time we send people into space on a more ambitious mission, longer, farther away, whatever it is, some new medical thing happens. And it sure would be nice to be able to anticipate those things and not just be taken by surprise all the time.” — Mark Shelhamer, Blue Dot

The spaceflight researcher was describing the wall between astronauts' medical records and research data. He knows which crew member got motion sick on one commercial flight but can't use it, because the rest of the crew didn't agree to share. He stressed the privacy rules exist for good reasons and that things are improving.

Blue Dot · 2026-10-09 Permalink → Listen →
Blue Dot Around 16:26 into the episode
Speaker 2

…Well, if somebody is doing one of my neurovestibular experiments in space, it would sure be helpful if I knew that that person had taken a medication for sleep, headache, nausea, whatever it might be, before they did my experiment. I don't necessarily get to know that because that's medical data.

Speaker 1

Can you ask them about that, though? Can you just, you know, can you request that, you know, voluntarily they let you know what medications they're taking?

Speaker 2

…flights, I have the information because they filled out questionnaires. For some of the flights, I don't have the information. But on one of them, in particular, I know who got sick because somebody told me who was on the flight, but I can't use that information because it's off the record, right? That person told me, but the rest of the crew didn't agree to tell me. So it's very unfortunate. It's like, I would say it's borderline criminal in the sense that there is the potential for us on the research side to be missing important information because of this incomplete data sharing, let's say. I don't want to say the sky is falling on this, right? It is improving, but I think there's room for improvement. And it leads me to a really critical point, which is that it seems that every time we send people into space on a more ambitious mission, longer, farther away, whatever it is, some new medical thing happens. And it sure would be nice to be able to anticipate. Of those…

Speaker 1

We're going to take a short break, but stay with us. When we return, we'll continue our conversation with Mark Shelhamer. Mark is the director of the Johns Hopkins Human Space Flight Laboratory and the author of the new book, Are We Ready for Mars? I'm Dave Schloem, and you are listening to Blue…

Speaker 2

Yeah. Wow. I'm really glad you pointed that out and that we were able to sneak a little physics lesson in there surreptitiously for people because I think they, you know, it may sound pedantic, but it's important to get your facts straight about the science if you're going to be talking about…

Speaker 1

It helps people to understand, you know, when they get that concept of, oh, they're falling around the Earth. You know, now I understand that. It's not that there's no, it's like I say, if, you know, if you stopped, if you stopped going 17,000 miles an hour, guess what happens? You fall right back…

Speaker names from our own diarization · position estimated from where the line sits in the episode
“I'll be honest with you, radiation confuses me. I shouldn't say that as a professional spaceflight researcher… Depending on who you talk to… deep space radiation is either the single biggest problem and a potential showstopper and a real major concern… or it's almost of no consequence at all. And really, I cannot figure out who's right.” — Mark Shelhamer, Blue Dot

The guest, a former chief scientist of NASA's Human Research Program and author of "Are We Ready for Mars?", was asked about radiation on the trip to Mars. He went on to separate acute solar-storm risk, which crews can shelter from, from galactic cosmic rays, which raise lifetime cancer risk.

Blue Dot · 2026-10-09 Permalink → Listen →
Blue Dot Around 28:23 into the episode
Speaker 2

…to each other at all. So, this idea of autonomy, we term it resilience. The idea that the crew is really going to have to have the tools, tangible tools, and intangible tools like knowledge and a mindset to solve problems that arise without a lot of help from anybody or any help from anybody.

Speaker 1

…in a radiation environment that humans have never been in beyond the moon, really, except for Artemis II is probably the farthest people, it is the farthest people have ever gone. But on the way to Mars, talk a bit about the radiation problems they would be facing, because that is of concern.

Speaker 2

…confuses me. I shouldn't say that as a professional spaceflight researcher, but it confuses me partly because I know many of the radiation researchers, the space radiation people, people who look at the biological effects of radiation. And depending on who you talk to, radiation, space radiation, deep space radiation, right, from between here and Mars, here and the moon too, but definitely Mars. Deep space radiation is either the single biggest problem and a potential showstopper and a real major concern. We dare not venture there until we really have a handle on it, or it's almost of no consequence at all. And really, I cannot figure out who's right. And we don't know. We won't know for sure. Definitely, we don't want to be cavalier about this. Definitely the radiation environment in deep space on the way to Mars is dramatically more intense than it is in low Earth orbit. So radiation effects…

Speaker 1

I think the main takeaway is that there are these multiple stressors on the human body when you're talking about any kind of space mission. We're going to take a short break, but stay with us as we continue our look at the challenges of human spaceflight and how hard it would be to send astronauts…

Speaker 2

Ah, yes, you're putting, you're coming to one of my favorite topics because space motion sickness paid my way through graduate school in the 1980s with the research grants for studying. Frank

Speaker 1

Borman barfed on the way to the moon to put you through school.

Speaker names from our own diarization · position estimated from where the line sits in the episode