There are no absolute medical contraindications for a human mission to Mars. But several “yellow flags” for astronaut health will have to be addressed by technology or drugs, according to several studies published following a private space mission in 2021.

“There is no medical reason why humans couldn’t go to Mars and back,” Christopher Mason of Cornell University said in a press conference call Monday. “We probably won’t be able to make multiple trips back and forth. But the human body adapts to space. And we can have attenuators of radiation and microgravity effects. »

Mr. Mason was the principal investigator of the international team that analyzed data from the private Inspiration 4 mission. More than two dozen studies were published Tuesday in the journal Nature Communications. Inspiration 4 flew in a SpaceX Dragon capsule and was financed and commissioned by tech billionaire Jared Isaacman, whose other project is repairing the Hubble Space Telescope.

One of the main risks of a long-term mission far from Earth’s protective magnetic field is a narrowing of the kidney channels. The risk of kidney stones is increasing and mouse modeling showed “permanent damage and impaired functioning” of the kidneys, according to a study published by researchers at University College London (UCL).

This kidney problem had been observed in other medical monitoring of astronauts on long-term missions in Earth orbit, but it had been attributed to osteoporosis linked to microgravity, which increases the amount of calcium in the urine. London researchers have determined that microgravity alters the management of salts by the kidneys.

Medication could restore normal functioning of the kidneys, or an exercise regimen countering microgravity could be solutions to this problem.

Increased exposure to radiation from the Sun when leaving Earth’s orbit has been linked to heart problems since the Apollo lunar program. One of the studies shows that three molecules, for which there are inhibitor drugs, are among the causes of these heart diseases. Immune system disorders, particularly the lymphatic system, have also been noted.

The Inspiration 4 mission spent only three days in orbit, but at an altitude of 600 km. As the protection of the Earth’s magnetic field decreases with altitude, the radiation dose to which they were exposed was therefore similar to that of a nine-month stay on the International Space Station, which is at an altitude of 400 km. A Mars mission would expose astronauts to ten times higher doses of radiation from the Sun.