The International Space Station (ISS) is an incredible feat of engineering, designed to support human life in profoundly inhospitable conditions. But the tiny metal bubble in the big black void can only do so much. Life in space, with zero gravity and higher exposure to cosmic radiation, can have serious consequences for spacefarers’ health.
Now, a team including both ground-based scientists and NASA crew is taking health research to the final frontier. Their results may help prevent dangerous blood clots for astronauts on missions—and lead to better treatments for clotting and immune disorders back on Earth.
How space affects blood health
Researchers had known for decades that astronauts on missions are more likely to develop blood clots, and longer missions may be particularly hazardous, says Matthew Rondina, MD, professor of internal medicine and pathology at University of Utah Health and the Utah-based site lead for the project. “As the duration that astronauts spend in space increases, we believe the risk of blood clots likely continues to accumulate,” Rondina says.
In the isolated environment of a space station, clots can present a serious problem, adds Hansjorg Schwertz, PhD, MD, project lead, physician at Billings Clinic, and adjunct assistant professor of occupational medicine at U of U Health. “You don’t want to have astronauts developing any occlusive thrombi [blood clots] up in space,” Schwertz says. “It requires a lot of logistics and a lot of treatment.”
Schwertz and Rondina are working together with NASA astronauts, who will do experiments on the ISS that show how spaceflight affects blood cells.
The team is specifically looking at platelets—cells that are directly involved in blood clotting—and megakaryocytes, bone marrow cells that produce platelets. After growing megakaryocytes and platelets aboard the ISS, researchers will analyze their gene activity, proteins, and functionality to learn how space exposure changes them.
Taking science from Earth to space
The cells launch into space November 4, 2024. But the road to get them there was a long one.
The lab has already been analyzing how platelets and megakaryocytes are affected by simulated space conditions. They’ve taken blood cells to a particle accelerator to expose them to simulated cosmic galactic rays, the high-energy particles that bombard astronauts in space. And they’ve grown cells in a container that constantly, slowly rotates, leaving them adrift in simulated microgravity.
Their experiments so far have detected a few changes that could be important for platelet function: genes involved in inflammation, immune regulation, and cellular energy generation, among others. But while their simulated space conditions are the best that can be achieved on Earth, no simulation is perfect. So it’s critical to test how cells respond to real-life space conditions.
The land-based researchers’ job isn’t over when the cells go up to the ISS. “Once they’re up there, we’ll be working in real time with the astronauts for a lot of the experiments,” Rondina explains. “We’ll be doing a set of ground-based control experiments that completely mimic and parallel what’s occurring on the ISS.”
Mirroring the astronauts’ actions—including any unplanned deviations that may occur—will ensure, as much as possible, that any changes between the cells on the ground and the cells in space are a direct result of the extraterrestrial environment.
Down-to-earth results
The results will have the potential to inform better health care for people both in space and on Earth, Rondina says. “This may allow us to identify new genes and pathways that regulate platelet production and clotting,” he explains. “We think a lot of those pathways likely have relevance to diseases that occur in normal gravity conditions.” In addition to clotting, platelets regulate important aspects of the immune system, so platelet dysfunction may also be involved in some immune disorders. Understanding them could help researchers understand why those diseases occur and how to prevent or treat them.
Schwertz adds that, after so much preparation, the launch of the experiment to the ISS feels akin to saying farewell to a family member. “There’s sadness because this part is done now, but also so much excitement and thankfulness for how it worked out so far.”
