Researchers Study How Martian Gravity Affects Skeletal Muscle

A team of international scientists examine the impact of reduced gravity on muscle tissue in mice aboard the International Space Station.

Mar. 21, 2026 at 9:39pm

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A team of researchers from the University of Rhode Island, Harvard Medical School, and several international institutions have conducted experiments aboard the International Space Station to study how Martian gravity would affect skeletal muscle in humans. The study involved exposing mice to varying levels of gravity, including 0.33g (close to Mars' gravity), and analyzing the impact on muscle weight, strength, and performance. The results suggest that 0.67g is a critical threshold for mitigating muscle atrophy caused by prolonged spaceflight, providing important insights for future missions to Mars.

Why it matters

As NASA and the China National Space Agency plan to send astronauts to Mars in the coming decade, understanding the effects of Martian gravity on human health is crucial. Skeletal muscle is essential for movement, strength, and metabolic health, and its loss in low-gravity environments could pose significant challenges for astronauts during long-duration space missions and upon their return to Earth.

The details

The research team, composed of scientists from institutions in the US, Japan, and elsewhere, conducted experiments on 24 mice sent to the Kibo experimental module on the International Space Station. The mice were placed in a centrifuge device called the Multiple Artificial-gravity Research System (MARS), where they were subjected to four different levels of gravity - microgravity, 0.33g, 0.67g, and 1g - over a 28-day period. The mice were then returned to NASA's Kennedy Space Center, where researchers at the University of Rhode Island's Metabolism and Muscle Biology Lab analyzed their muscle weight, strength, and movement.

  • The mice were subjected to the gravity experiments for 28 days aboard the International Space Station.
  • The mice were returned to NASA's Kennedy Space Center after the experiment for post-flight sampling and analysis.

The players

Marie Mortreux

An assistant professor in the University of Rhode Island's College of Health Sciences who leads the Metabolism and Muscle Biology Lab.

Mary Bouxsein

A co-author on the study and a professor at Harvard Medical School who developed a ground-based mouse model of partial gravity in the early 2010s.

NASA

The United States space agency that plans to send astronauts to Mars in the coming decade.

China National Space Agency (CNSA)

The Chinese space agency that is also planning to send astronauts to Mars.

Japan Aerospace Exploration Agency (JAXA)

The Japanese space agency that developed the MARS centrifuge device used in the experiment.

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What they’re saying

“While we can simulate spaceflight on Earth in humans, it's extremely complicated and costly. We have centrifuges that can be used to temporarily expose humans to certain gravity levels, but it is not homogeneous nor constant. We used gravity levels that were equally separated, to have a better picture of the dose-response of each system to gravity. The test group that was exposed to 0.33g was extremely close to Martian gravity (0.38g). Our findings for that group can be translated into actions to enable Mars exploration.”

— Marie Mortreux, Assistant Professor, University of Rhode Island

“Since this mission aimed to assess gravity as a continuum, we were perfectly positioned to see if our ground-based results had similar outcomes when reduced mechanical loading was applied in orbit. Working with an international team was challenging and exciting. I think my experience working in Italy, France, and the United States prepared me for those big-scale collaborations.”

— Marie Mortreux, Assistant Professor, University of Rhode Island

What’s next

The research team plans to continue studying the impact of Martian gravity on other physiological systems, such as bone health and cardiovascular function, to provide a comprehensive understanding of the challenges astronauts may face during long-duration missions to the Red Planet.

The takeaway

This study provides critical insights into the effects of Martian gravity on skeletal muscle, suggesting that 0.67g is a key threshold for mitigating muscle atrophy. These findings will help inform the design of future spacecraft and habitats to support the health and performance of astronauts during and after long-duration space missions to Mars.