Are astronauts at a higher risk of cardiovascular-related deaths?

29 Jul 2016

A new study in the US reports that members of the wildly successful Apollo space programme are experiencing cardiovascular deaths at higher rates than expected.

Pinning the findings to deep-space radiation, Michael Delp’s research (published in Scientific Reports) looked at astronauts from the nine crewed Apollo missions that went into deep space.

Here, they were exposed to levels of radiation far higher than what we receive from the safety of Earth and it resulted in cardiovascular issues affecting deep-space astronauts over four-times the rate of other astronauts.

This is particularly telling with regards future plans of sending humans to Mars, or even to a base on the Moon – the former a plan of NASA and SpaceX, the latter that of Roscosmos.


One-third of Apollo astronauts have died, eight in total. One of these, Edgar Mitchell, died after his data analysis had been completed for the study.

To test out his radiation theory, Delp and his team exposed mice to the type of radiation that deep-space astronauts would have experienced on the Apollo missions.

After six months (which Delp claims equates to 20 human years) the mice demonstrated notable impairment of arteries.

“What the mouse data show is that deep-space radiation is harmful to vascular health,” Delp said.

SpaceX founder Elon Musk thinks we could send humans to Mars in less than a decade. SpaceX is working with NASA to send un-crewed spacecraft to the Red Planet in preparation of humanity’s arrival and, should everything go according to plan (which is nowhere near a given), “we should be able to launch people in 2024, with arrival in 2025,” Musk said.

The radiation risk will be far higher on such a mission, given the longer flight time to get to Mars – years rather than days.

NASA is currently developing ways to get to Mars, with the recently completed One-Year Mission providing critical insight for any longer-distance travel. Working out how to protect astronauts from radiation is one of the key challenges.

“The results demonstrate that space-relevant irradiation induces a sustained vascular endothelial cell dysfunction,” reads Delp’s report.

“Such impairment is known to lead to occlusive artery disease, and may be an important risk factor for CVD [cardiovascular disease] among astronauts exposed to deep-space radiation.”

Main lunar landing image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic