Stem cells grown aboard the International Space Station multiplied faster and more robustly than identical cells grown on Earth, a finding that could reshape how scientists develop treatments for cancer and other diseases.
Researchers from NASA and the University of California, Berkeley, sent hematopoietic stem cells, which give rise to blood and immune cells, to the ISS in 2025. The cells were cultured in microgravity for 14 days. When they returned, the space grown cells had expanded more than those kept in ground based labs, and they retained their ability to develop into different types of blood cells.
Why microgravity matters for cell growth
On Earth, gravity compresses cells and limits their ability to divide and multiply in lab cultures. In the near weightless environment of low Earth orbit, cells float freely and can expand in three dimensions. This allows them to behave more like they do inside the human body. The space grown stem cells also showed lower levels of stress and aging markers compared to Earth grown controls. That suggests microgravity may provide a more natural environment for certain types of cell production.
What this means for patients
Stem cell therapies hold promise for treating leukemia, lymphoma, autoimmune disorders, and genetic blood diseases. But a major obstacle has been producing enough healthy stem cells in the lab to treat patients. Current methods often yield limited numbers of cells, and the cells can lose potency during expansion. The space based results point to a potential workaround: manufacturing stem cells in orbit, then shipping them back to Earth for medical use. The research team is now planning follow up missions to test whether the space grown cells can safely and effectively be transplanted into animal models.
Who is behind the work
The project is part of NASA’s broader effort to use the ISS as a platform for biomedical research. The University of California, Berkeley, led the experiment design, and the cells were launched on a SpaceX cargo mission. Local communities in California have followed the research closely, as the state is home to major stem cell research institutes and cancer treatment centers. For residents and medical professionals there, the possibility of a space based supply chain for stem cells is not science fiction. It is a near term goal.
The bigger picture
The study adds to a growing body of evidence that spaceflight can alter biological processes in ways that benefit medicine. If future experiments confirm the safety and efficacy of space grown stem cells, the approach could one day help meet the global demand for transplantable cells. For now, the work remains in early stages. But the cells that grew faster in orbit have already given researchers a clearer target: learning how to replicate those conditions on Earth, or deciding to keep growing them among the stars.
