Fig. 1: Number of publications for rare disease and space health through time.

Rare disease, despite being individually rare collectively affect a significant proportion of the population and thus elicit a higher research output than space health. Even with the revolutions in genomics, genetic studies in astronauts remain rare. Despite commonality of genetic basis for rare disease, genetic studies have increased in the field of rare diseases but they do not represent a dominant research topic in the scientific literature nor even, surprisingly, a growing proportion of the scientific literature. Consideration of “natural history” seems mostly absent from the space health literature but appears as often as genetic in the rare disease literature. The number of annual publications for the keywords “rare disease” (blue) and “astronaut” + “health” (orange) from 1990 to present day (2021). Data was additionally generated for keyword combinations such as “rare disease” and “natural history” (green), “genetic” and “astronaut” + “health” (yellow), and “genetic” and “rare disease” (red). No publications were found for the “astronaut” + “health” and “natural history”. All data was generated using Web of Science. Data in Source data 1.