Humans to Mars, But How Many? A Historical Review of Crew Size Determinations for Mars Missions

Three-quarters of a century have passed since the first engineering study of a human mission to Mars in 1948. During that time, dozens of study teams at NASA, its contractors, and other organizations in the U.S. and abroad have confronted what NASA mission architect John Connolly and his colleagues have called “the ultimate systems challenge.” This historical review of those studies focuses on the question of crew size and its relationship to crew workload.