How space changes our cells: Insights from the ISS

When we think about space, we often picture rockets, astronauts, and distant planets. But some of the most important discoveries are happening at the cellular level.

Scientists are studying how our cells respond to space – especially to changes in gravity – and what that could mean for future missions and for health here on Earth.

Much of this work is being done aboard the International Space Station (ISS), where researchers are running cell-based experiments to better understand how space affects living systems.

These studies are already yielding insights into bone loss, muscle atrophy, heart disease, and more.

Studying cells in space

Scientists have been leading several recent investigations in collaboration with the Japan Aerospace Exploration Agency (JAXA). Their focus is how cells detect and respond to gravity – or the lack of it.

In one investigation, Cell Gravisensing, researchers explored the inner workings of animal cells to understand how they sense gravitational changes. This process is still a mystery, but the potential payoff is big.

If we understand how cells detect gravity, we might be able to develop treatments for muscle and bone loss that happen both in space and on Earth.

Heart cells react fast in space

Some astronauts experience noticeable changes in their cardiovascular systems during space missions. Blood volume drops. The heart pumps less.

A previous study called STaARS Bioscience-3 looked into this. After just three days in orbit, blood vessel cells showed changes in the expression of over 11,000 genes.

Brain cells in space microgravity

Another experiment, STaARS BioScience-4, focused on neural stem cells – the kind that eventually become part of the brain and spinal cord.

Researchers observed that in microgravity, these cells produced and consumed energy differently. They also broke down more cellular components, possibly to adapt to the new environment.

The study emphasized a key issue for long missions: energy. “The finding also highlights the importance of providing astronauts with sufficient energy for cognitive and physiological function on future missions,” the authors note.

Goldfish scales show bone changes

Goldfish might seem like an odd choice for space research, but their scales are surprisingly useful. They contain many of the same proteins, minerals, and cell types found in human bone.

The JAXA Fish Scales investigation exposed goldfish scales to simulated and real microgravity, as well as triple Earth gravity.

The outcome? Goldfish scales can be used as a model to understand how human bones react to space conditions. That could be a big help in developing countermeasures for astronauts and for people suffering from bone diseases.

Mouse cells and radiation

Rodents are also proving valuable in space biology. In the Stem Cells experiment, scientists studied how embryonic mouse stem cells responded to spaceflight. Some cells were left unaltered, while others were mutated to be more sensitive to radiation.

There were no chromosomal differences in the unaltered cells between space and ground samples. But in the mutated cells, researchers found more DNA abnormalities.

“The work could enhance the understanding of radiation effects on human cancer and improve risk assessment for long-duration missions to the Moon and Mars,” said the researchers.

Heart muscle adapts quickly

In another related study, tissue samples from the Rodent Research-1 (RR-1) mission were analyzed using data from NASA’s GeneLab. The team discovered that the heart muscle can adjust to the stress of space in just 30 days.

Genetic changes suggested that this adaptation could help the body survive in space – and might even inform treatment for heart disease on Earth.

Why space research matters

Space is more than a destination. It’s a laboratory that pushes the limits of science in ways we can’t achieve on Earth. The unique environment of microgravity lets researchers see how cells, organs, and even entire systems behave under stress.

Experiments aboard the ISS not only prepare us for longer missions to the Moon and Mars, but also spark new ideas for treating diseases, extending healthy lifespans, and improving life on our own planet.

Space reminds us that discovery doesn’t just happen out there among the stars – it also happens inside us, one cell at a time.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–