Orbital Blastoids Probe Early Human Development in Microgravity

China sent stem-cell–derived embryo models (blastoids) to the Tiangong space station to study how the earliest stages of human development behave in microgravity. The experiment includes peri-implantation and peri-gastrulation models cultured for five days and then frozen for Earth-based analysis, with a ground-control batch for comparison. While it cannot prove humans can reproduce in space—blastoids are not real embryos and five days is a small window—it will provide concrete data on whether early development can tolerate off-Earth conditions and guide future research and engineering needs.