Abstract

Matti Häyry has argued that space exploration aimed at human settlement is both irrational and morally impermissible. Such projects, he claims, expose others—including future generations—to serious risks that were not autonomously chosen and which may be harsh, oppressive, and difficult or impossible to escape. Given the increasing institutional interest in extra‐planetary habitation, these concerns warrant serious engagement. This paper refutes Häyry's use of the precautionary principle as a decisive moral rule in this context because the principle is ill‐suited to long‐term, future‐directed activities in that it treats abstention as ethically neutral. The moral failure of human settlement in space, if there is one, lies not in space exploration qua activity—but in mission frameworks that exclude normative, social, and philosophical perspectives from their design and governance.