Science2 publishers3 min readPublished
NASA and ESA will share Crew-13 blood draws to study clotting in weightlessness
NASA and ESA will coordinate blood draws from Crew-13 astronauts in a joint clotting study, one of six human studies on the mission. The study asks why weightlessness disturbs venous blood flow in some astronauts but not others, and answering that depends on how many crew take part.
The Scientist · Science desk
What happened
- NASA and ESA are starting Venous Haemostasis, a new joint study of blood flow and clotting in microgravity, on the SpaceX Crew-13 mission to the International Space Station.
- The two agencies will coordinate blood collections so astronauts are drawn less often while their analytical measurements are combined.
- Crew members get MRI scans, jugular vein ultrasounds, blood pressure checks and blood draws before, during and after flight to track changes in blood flow and composition.
- Crew-13 also carries five other human studies, including a B-vitamin test against eye changes and a treadmill comparison for Artemis exercise planning.
Compiled by The ScientistSomething wrong?How this is made
Why it matters
- capability If the study finds measurements that single out astronauts whose venous flow is disrupted, NASA could aim clot prevention at specific crew members instead of treating everyone the same.
- precedent A working shared-collection schedule would let NASA and ESA run joint studies on the same astronauts without each program drawing its own blood.
- decision Zero T2's treadmill comparison will feed the choice of whether Artemis and deep-space exercise plans can do without a treadmill on spacecraft too small to carry one.
Jason Lytle, one of the study's principal investigators and a cardiovascular researcher at NASA's Johnson Space Center in Houston, laid out the problem in two steps. "In space, weightlessness can disrupt normal blood flow in astronauts' veins," he said [4]. "Irregular and slow blood flow can increase the risk of blood clot formation, a serious health condition. Venous Haemostasis will help us understand why these changes may occur in some astronauts but not others." [5]
His last sentence is a question about differences between people. To answer it, the study needs a baseline for each astronaut and enough astronauts for both groups to show up. The protocol supplies the baseline. Every measurement runs before, during and after flight [6], so each person's in-flight readings can be compared with their own preflight state. The headcount is harder to judge. The release does not say how many Crew-13 astronauts enroll, how many draws the coordination with ESA removes, or which assays each agency runs on a shared tube.
NASA calls the joint arrangement new, and says it builds on earlier studies of blood flow in space by combining the two agencies' efforts [2]. For the crew, it means fewer needles [3]. For the science, it means one tube has to serve both agencies' measurements [3].
Of the six human studies on the mission [15], Zero T2 has the plainest comparison built into it: astronauts who use the station treadmill for aerobic exercise against those who do not [13]. NASA wants the answer for Artemis and deep-space missions, where spacecraft size could limit or eliminate treadmill use [13]. The comparison is only as clean as the split. If the crew who skip the treadmill also differ in fitness or workload, the result measures those differences along with the treadmill.
B-Complex asks whether a daily B-vitamin supplement can reduce or prevent Spaceflight-Associated Neuro-ocular Syndrome, a condition that can change astronauts' eye structure on long missions [9]. NASA's stated basis is that past research suggests daily B vitamins in flight may help protect against it [9]. Participating crew take the vitamins before, during and after flight and have their vision tested. The study will also check whether the supplement changes how their blood vessels function [10].
The clotting study's nearest payoff is for the crew themselves: NASA says results will inform preventive measures for at-risk crew members [7]. The agency also hopes the work may lead to better ways to prevent and treat blood clots on Earth [7]. NASA states that second aim as a hope, and the protocol as described measures only astronauts [6].
Michael Stenger, the Human Research Program's chief scientist at NASA Johnson, described the mission's studies this way. "Together, these investigations will help NASA better understand how the human body responds to spaceflight and whether specific strategies can effectively protect astronaut health and performance," he said [14].
What to watch
- NASA or ESA publishing how many Crew-13 astronauts enroll in Venous Haemostasis and how many blood draws the joint schedule removes.
- Whether Zero T2 reports how crew were assigned to the treadmill and no-treadmill groups.
- First Venous Haemostasis results on whether preflight measurements predict which astronauts show disrupted venous flow.