What the Polaris Dawn mission could reveal about human health in space

SpaceX’s Polaris Dawn mission, in which billionaire Jared Isaacman and three other crew members traveled to space in a Crew Dragon, has made headlines for including the first-ever private spacewalk. While the flight has been hailed as historic for that reason, Isaaman has said that the trip is not merely for fun but is making contributions to science as well. 

The research in the Polaris program, planned to be three flights, is particularly focused on human health and the effects of spaceflight on the body. The current mission will be studied by Baylor College of Medicine, with the astronauts giving blood and going through extensive biomedical testing both before and after the flight.

But what sets the Polaris Dawn mission apart is its altitude, 870 miles above the Earth’s surface to be exact. That’s far higher than the typical altitude of the International Space Station, at around 250 miles, and makes Polaris Dawn the farthest humans have been from Earth since the Apollo missions. 

That altitude took the craft through Earth’s inner Van Allen belt, a region of charged particles that protect the planet from dangerous radiation. The crew members are fitted with sensors to measure their cumulative radiation exposure over the mission, and the spacecraft interior is fitted with a sensor to detect the different types of radiation in the environment.

“It’s an opportunity to see what kind of [radiation] exposure that we get as they get further and further away from the surface of the Earth,” explained Baylor’s Translational Research Institute for Space Health deputy director Jimmy Wu. “That’s something that we don’t have a whole lot of data on, because we’ve been limited to the number of humans that have been that far. So that’s critically important to understand.”

From a health researcher’s point of view, more data is always welcome, whether it’s from a space agency mission or a private one. Though the Polaris Dawn mission is much shorter than a typical astronaut rotation on the International Space Station, at five days rather than six months or more, that still provides an opportunity for a different type of research.

If you want to look into the long-term effects of spaceflight on health, such as loss of muscle and bone mass, then you need a longer-duration mission. But with certain effects of spaceflight, the body adjusts to a baseline within a few days or a few hours, and these are ideal research topics for short missions.

Astronauts can experience space motion sickness when they enter or leave a microgravity environment, and it’s not yet known why some people suffer from this more than others, especially in the first few days of spaceflight.

While being space sick seems like more of an annoyance than a major problem, Wu points out that being impaired immediately following a launch or landing event could be a big issue. 

“You go to the Moon. There’s no welcoming committee to take care of you when you land,” he said. “What would happen if there was some sort of mishap during landing, and you had to get out? Are you going to be able to functionally do that if you’ve lost your orientation and sense of up and down?”

Another key area of health research is the relationship between different factors in spaceflight and how they affect each other. It’s not just about understanding the effects of either microgravity or radiation exposure or isolation and confinement — it’s about understanding the cumulative stresses on the body that going to space entails.

While proponents of space tourism argue that it is increasing access to space, even democratizing space access, that can be hard to swallow when the only people going to space are billionaires like Isaacman and their friends.

However, it’s also true that the astronauts who currently fly on space agency missions are not representative of the general public. Some of that is necessary — it’s only sensible to select astronauts who are healthy enough to withstand the physical challenges of spaceflight — and some of it is a legacy of racism, sexism, and who is perceived to be worthy of becoming an astronaut.

Efforts to diversify international astronaut corps are underway, and the European Space Agency recently selected its first disabled astronaut for training. But still, the people flying on space agency missions are a very limited slice of the human population, and so the only data we have on spaceflight health outcomes are related to this small group. 

“I think it’s really important to understand the breadth of humanity so that we can understand the full spectrum of how humanity would perform in space flight, not just the folks who were our early pioneers,” Wu said.

Though commercial astronauts to date have been primarily, although not exclusively, white men, they have represented a wider range of ages and backgrounds than is typical for professional astronauts. And future commercial missions could help widen the pool of data on human health in space. The Polaris Dawn crew consists of an equal balance of men and women, for example, allowing for comparisons between genders.

TRISH is setting up a database that will collect biomedical data from both Polaris Dawn and future commercial space missions. The aim is to collect data from a wider range of people, not just highly trained, young astronauts with no medical conditions, to see how people with preexisting conditions like diabetes or cardiovascular disease fare on space missions.

“We have got to start collecting that data because we don’t know how these [conditions] would behave in space,” Wu explained.

One experiment on the Polaris Dawn mission that could have an outsize impact is something that seems, on the face of it, quite simple: testing out a miniaturized ultrasound scanner that the crew can use to scan themselves and collect medical data. The researchers are looking at not only the performance of the device but also the best way to train the crew on its use.

Although adapting hardware for space comes with its own challenges, the preparation for using a handheld medical scanner, particularly for people who aren’t trained medical professionals, is about education and procedure.

“There’s a line of research around that: how do we provide pre-flight training before they go on the mission, so they can at least understand some fundamentals?” Wu explained. “And then, can we provide just-in-time training? So as they’re preparing for the actual activity, can you give them a refresher?”

Finding the best way to teach nonmedical professionals to use diagnostic devices, and making those devices as small and robust as possible, turns out to not only be useful in space. It could also be invaluable here on Earth, such as in rural settings or a region where people don’t have access to doctors.

“We talk about the concepts of health equity and being able to serve underserved low resource environments,” Wu said. “If you can keep someone healthy in the remoteness of space, you should be able to do that anywhere on Earth.”