Fig 1. Illustration of the NASA astronaut selection process flow.

Numbers of applicants at each stage are drawn from the 2009 selection data obtained via FOIA request except the HQ number which is estimated from the 2013 cohort wherein it was 483 persons. Approximate numbers of applicants moving between each sub-group are stated as percentages and include medical disqualifications (occurring during the interview process), which were not identified in the data provided by NASA. The geometric areas of the shapes representing each group are approximately to scale.