Astronaut Selection: Implications for the New Era of Spaceflight

The rapid expansion of commercial human spaceflight is forcing a re-examination of how we decide who is “fit to fly” in space. For six decades, astronaut selection has been dominated by national space agencies using stringent, mission-driven criteria grounded in risk minimisation and long-duration operational demands. Contemporary standards such as NASA-STD-3001 and agency-specific medical regulations embed a philosophy in which astronauts are rare, heavily trained national assets expected to tolerate extreme environments with minimal performance degradation. In contrast, commercial operators aim to fly large numbers of spaceflight participants (SFPs) with highly heterogeneous medical and psychological profiles, under a US regulatory regime that emphasises informed consent and currently imposes very limited prescriptive health requirements on passengers. This article reviews the evolution and structure of traditional astronaut selection, outlines emerging approaches to screening and certify-ing commercial spaceflight customers, and explores the conceptual and practical gap between “selection” and “screening”. Drawing on agency standards, psychological se-lection research, and recent proposals for commercial medical guidelines, it proposes a risk-informed, mission-specific framework that adapts lessons from government as-tronaut corps to the needs of commercial spaceflight. We argue that future practice must balance inclusion and market growth with transparent, evidence-based risk manage-ment, supported by systematic data collection across government and commercial flights.