Space-grown mini-hearts beat Earth labs in production speed, study finds

Researchers report that mini-hearts derived from human stem cells can be grown aboard the International Space Station at a far higher rate than on Earth, thanks to microgravity letting cells float freely without the need for aggressive stirring. This space-based production could yield thicker, more robust heart tissue and organoids for drug testing and potential future therapies, even as astronauts’ hearts undergo microgravity-induced changes. While space-grown tissues show promise and may eventually aid heart-disease research and transplants, human clinical use remains years away and further experiments—like on the SpaceX CRS-35 mission—are planned to scale and validate the approach.