SpaceX Crew Completes First Citizen Spacewalk

KATHLEEN DAVIS: This is Science Friday. I’m Kathleen Davis, filling in for Ira Flatow this week. A bit later in the hour, what if we get it right? A conversation about solutions to preventing the worst outcomes of climate change.

Plus, we’re headed back to school. We’ll unpack what new smartphone bans in schools mean for the teachers and the students, and what the research says about the effects of social media on kids mental health. But first, big news in the world of commercial spaceflight.

Early Thursday morning, two of the four crew members of SpaceX’s Polaris Dawn mission became the first civilians to complete a spacewalk. Joining me now to fill us in on the details and bring us up to speed on other top science news of the week is my guest, Jason Dinh, Climate Editor at Atmos Magazine, based in Washington, DC. Jason, welcome back to Science Friday.

JASON DINH: Thanks for having me.

KATHLEEN DAVIS: OK, so to start out, can you give us a quick refresher on the basics of SpaceX’s Polaris Dawn mission?

JASON DINH: Polaris is this collaboration between SpaceX and a billionaire entrepreneur named Jared Isaacman, who bankrolled the project and is actually one of the crew members on board. The others include two SpaceX engineers and a former Air Force pilot. This particular mission is historic for a couple of reasons.

First, as you mentioned, this is an all civilian crew. And it’s the first time a civilian is doing a spacewalk rather than, say, a NASA pilot. The second milestone is that it actually reached a historically high altitude. They ascended to 870 miles above earth’s surface.

That’s about three times higher than the International Space Station, and it’s the highest orbital altitude humans have reached since the Apollo moon mission in 1972. Now, this is just the first of three Polaris missions. And the goal of all of this is to develop the technology that SpaceX thinks they’ll need to one day send people to Mars.

KATHLEEN DAVIS: So who are these civilian astronauts? And what did they do on their spacewalk?

JASON DINH: The civilian astronauts are Jared Isaacman, the billionaire, two SpaceX engineers, and a former Air Force pilot. And the spacewalk itself was pretty simple. On Thursday, the crew opened up the hatch.

And Isaacman, the billionaire, got out of the vehicle, did some tests on his spacesuit, and got back in. Then one of the SpaceX engineers did the same thing. And then they closed up the shop, finished the mission all within two hours or so.

KATHLEEN DAVIS: Mm, so how is this spacewalk different from the ones done by NASA or other countries government-run space agencies.

JASON DINH: There have been quite a few spacewalks in history. A lot of them have been on the International Space Station, for example. And each one really has its own objective. A lot of the stuff on the Space Station is to do maintenance and assembly. And this particular one was to test out these spacesuits that SpaceX thinks one day might lead to the ones that they’ll send to Mars.

KATHLEEN DAVIS: Mm-hmm, so the civilian astronauts are continuing with their mission, doing additional experiments, and they’re expected to return to Earth in the next few days. So let’s wish them the best of luck and move on to our next story, which is also going to keep us high up in the sky for a little bit longer. Scientists have recently found germs some 10,000 feet up. I have a lot of questions. But first, what motivated scientists to look towards the sky for pathogens?

JASON DINH: This is such an interesting study. So the scientists first got this idea based on this mysterious disease called Kawasaki disease, which causes fevers and rashes and sometimes heart attacks. It’s not clear what causes that disease.

But these researchers noticed that cases in Japan would surge when winds blew from Northeast China. And when those winds got to California, cases surged there, too. So these researchers flew their airplanes up to 10,000 feet in the air to catch those winds and see if there were pathogens up there. And what they found was that there are actually hundreds of species of bacteria and fungi living up there.

And they think they could have flown over a thousand miles. These germs were alive. So the team actually grew them on a Petri dish back in the lab. And about a third of them can cause disease in humans. This includes E. coli, C. diff, and staphylococcus, for example.

KATHLEEN DAVIS: And so, just to clarify, were these germs found in planes or just in ambient space?

JASON DINH: They were just in ambient space. Basically, they flew the planes up there, opened up a little air funnel, and then filtered out what was in the air.

KATHLEEN DAVIS: Wow, OK, so could germs so high in the sky really infect us down here on Earth?

JASON DINH: The evidence isn’t strong enough to say that quite yet. That might not even be likely that diseases are spreading through the air this way. The concentrations of microbes was really low.

But the fact that they’re up there at all and they’re traveling such long distances is enough to concern some scientists that diseases could spread around the globe as these airborne germs fall back to Earth. The researchers are actually working on follow-up experiments now, seeing what happens to human lung cells when they’re exposed to this cocktail of high altitude microbes. But as of now, it’s not clear or even likely that these airborne germs are causing or spreading disease.

KATHLEEN DAVIS: Mm, OK, our next story, we’re going to stay up in the clouds for just a little bit longer. Some new research shows that cities are rainier than their surrounding areas. What is going on here?

JASON DINH: You’ve probably talked a lot on this show about the urban heat island effect, the idea that cities are hotter than their rural neighbors. And this is a newly discovered variation of that. Scientists have now found evidence for an urban rainfall island effect.

By analyzing two decades of satellite data from over a thousand cities, they found that cities get significantly more rain than nearby rural areas. How much more varies between cities. But this is really a global phenomenon. 2/3 of the cities in the study got more rain than their rural neighbors.

KATHLEEN DAVIS: Do scientists have any idea why this is happening?

JASON DINH: There are a couple of reasons. So, first, skyscrapers can actually slow down storms that come through.

KATHLEEN DAVIS: Huh.

JASON DINH: Yeah, air pollution can also seed clouds, which can then pour down rain. And then there’s heat from concrete and asphalt that can move air around the atmosphere in a way that promotes precipitation.

KATHLEEN DAVIS: OK, super interesting stuff. So our next story is about a disease that we don’t think about that much here in the US. And that’s cholera. A new report from the World Health Organization showed deaths from cholera soared last year. Tell me a little bit about what they found.

JASON DINH: You’re totally right that most of us haven’t thought about cholera being a big problem since, say, the 1800s when modern water treatments arose. But this analysis from the World Health Organization suggests that last year, we might have taken a step back. They found that in 2023, there was a 13% increase in cholera cases and a 71% increase in cholera deaths worldwide.

Just to jog your memory on this, cholera is a bacterial infection that spreads through contaminated food and water. It causes diarrhea, dehydration, and it can be fatal. And it typically affects lower income countries and places where people can’t access clean drinking water.

The most tragic part about this finding is that cholera is pretty straightforward and cheap to treat. All it takes is a bag of IV oral rehydration salts, maybe some antibiotics. But a lot of people in the world today still can’t even access that level of medical care.

KATHLEEN DAVIS: So even though it is so easy to treat, why is this still happening in this day and age?

JASON DINH: Yeah, 2023 in particular was interesting. The WHO says that the cases were actually rising because of climate change and the political conflict we saw throughout the years. So, for example, in Southern Africa, we saw extreme storms and droughts that led people to use less safe water sources, like boreholes or rivers.

And in Sudan, there was a cholera outbreak because a civil war is driving one of the world’s worst humanitarian crises. 10 million people have been displaced. They’re being packed into camps without proper sanitation to have food and safe drinking water.

It’s also worth noting that there is a cholera vaccine, but there’s just not enough supply to meet the demand. Only one company in the world manufactures them. And last year, there weren’t even enough doses to get them to at-risk places, like Sudan or Gaza.

KATHLEEN DAVIS: OK, let’s move on to our next story. I want to give a little bit of an update about something that we talked about on last week’s show. Hvaldimir, the beluga whale that may have been a Russian intelligence agent was found dead off the coast of Norway.

We mentioned last week that two animal rights groups said that the whale was shot. Police now say that there was no evidence of gunshot wounds. What is the latest on this whale, Jason?

JASON DINH: All in all, if you are concerned about animal cruelty, this seems like good news. Based on a forensic exam, the Norwegian police concluded that human activity did not directly kill Hvaldimir. They say he died after a 14-inch stick got stuck in his mouth.

And that could have prevented him from eating and could even explain why his stomach was empty when he was found. There were some superficial injuries, but they said there was no evidence that Hvaldimir was shot. So they’re ending their investigation and they’re going to publish a full report on everything they found in about two weeks.

KATHLEEN DAVIS: Ugh, well, rest in peace, Hvaldimir. Those tricky sticks can get anybody. So our last story is a wild story about the ability of eels to escape predators. What are these eels up to, Jason?

JASON DINH: Yeah, if you can count on me for anything, Kathleen, it’s bringing you a story about an animal that’s just so metal. So this study was published in the journal Current Biology. It showed that Japanese eels can escape the stomachs of their predators after they’ve been eaten. They swim back up the fish’s digestive track into its esophagus, and then they slide themselves tail first out of the fish’s gills.

You might be wondering, how can you tell what’s happening inside of this fish? Well, they actually use these really neat X-ray videos, which you can watch online. They did 32 trials where they fed an eel to a fish. And then they anesthetized the fish and put it under their X-ray video rig.

And they saw that 28 of those 32 eels tried to escape. Nine of them actually made it out. Of course, there were quite a few failed efforts. A few got stuck in the gills. A few went the wrong way and stuck their tails through the waste hole instead of the esophagus.

But really, the key to succeeding was speed. The eels could only survive 3 minutes in the fish’s stomach before it got cooked by the digestive fluids. And the ones that escaped got out within 1 minute.

KATHLEEN DAVIS: Jason, it’s a good thing you can’t see my face right now because I am making quite a grimace. Jason, that’s all the time that we have for now. Thanks so much for joining us.

JASON DINH: Thanks for having me. It’s always a pleasure.

KATHLEEN DAVIS: Jason Dinh, Climate Editor at Atmos Magazine based in Washington, DC.

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