There are good theoretical rationales for considering germline gene editing (GGE) as a recommended and perhaps even necessary procedure for future long-term human space missions. This paper examines the arguments for applying GGE in a hypothetical future scenario where future parents living on Earth make decisions about applying GGE to their future children with the goal of allowing them to participate in space missions. The paper presents an ethical rationale for GGE. The paper also recognizes an area of potential moral (...) controversy that is not so much related to the application of GGE itself, but to the risk of different perceptions of well-being by parents and children that may result in the need for genetically modified children to leave Earth against their will. (shrink)