As far as we know, animal development is a process that is unique to our planet. That does not mean, however, that development beyond our realm is impossible. As it starts to become feasible for us to look to the sky for another place to call home, we may start to appreciate the gravity of this question.
In this issue, Lei et al. investigate for the first time the repercussions of space travel on the first decisions made by mouse embryos. Developing a novel micro-incubator, capable of automatic micrography and fixation, harboring some 3400 two-cell embryos, they investigate the consequences of development after being projected into the stratosphere in the SJ-10 satellite [1]