Neural stem cells survived an unplanned delay returning from the ISS

By the Everything Space news desk · 06 Oct 2026 · written from the sources below

Image: Phys.org

The unexpected resilience of lab-grown neural stem cells after a prolonged, uncontrolled trip back from orbit could inform how astronauts might grow tissue for treatment in space.

Neural stem cell clusters sent to the International Space Station in early 2024 ended up spending far longer outside controlled lab conditions than planned, after bad weather repeatedly delayed the mission's return to Earth. The delay pushed the cells beyond the time frame researchers believed they could survive.

When the samples finally reached the lab at Uppsala Biomedical Center, their condition looked poor, with only fragments of cell clusters visible in some groups. Researchers were uncertain whether the experiment could still proceed, but after changing the growth medium and waiting, some cells began to slowly recover.

About a month later, scientists were able to run their planned experiments. Despite the prolonged stress, a portion of the cells survived and retained the ability to develop into nerve cells and support cells, performing normally in subsequent tests.

One standout finding involved cells housed in 3D-printed support structures, which survived and kept dividing across all test groups. Researchers say the unplanned extension of the experiment's timeline ended up revealing how much that structural support mattered for cell survival.

The work is part of a larger international collaboration drawing on multiple spaceflight experiments to study cell behavior in microgravity. Scientists are particularly interested in whether such resilience could eventually support growing replacement cells or tissue for treating injuries and illness during long crewed missions, using induced pluripotent stem cell techniques that can convert ordinary skin cells into versatile stem cells.

Beyond spaceflight applications, the research team is also using microgravity exposure to study cellular processes tied to conditions on Earth, including back pain and type 1 diabetes, and plans to try recreating microgravity-like effects in ground-based lab settings.

Written in Everything Space’s own words by our news-desk model from the sources above, and checked against them in code: every number in this report appears in its sources, and no sentence is copied from them.