A brief history of spaceflight from 1961 to 2020: An analysis of missions and astronaut demographics

Abstract

Human spaceflight and the characteristics of people who become astronauts have changed over time. Here we present an analysis of n=1,265 manned spaceflights by n=562 astronauts from 1961-2020 to investigate historical trends over time and between space agencies in terms of astronaut demographics and spaceflight duration. Generalized linear models and generalized linear mixed models were implemented with adjustments for all available demographic data as covariates. Women continue to be underrepresented as astronauts, and were younger, had fewer children, and were less likely to have a military background than their male counterparts. Astronaut age has increased over time, although this increase was significant only for first-time spaceflights. The proportion of astronauts from civilian backgrounds has generally increased over time, although there is evidence this trend may be reversing. Spaceflight duration has increased over time, and has been longest for ROSCOSMOS cosmonauts and shortest for Chinese taikonauts. There were also differences between space agencies in terms of astronaut demographics, particularly between NASA and ROSCOSMOS, with first-time NASA astronauts more likely to be women, civilian and older than first-time ROSCOSMOS cosmonauts. As humankind embarks on exploration-class missions back to the lunar surface and then onward to Mars, and with new nations and commercial entities entering the international space community, the nature of spaceflight, and the diversity of the astronauts, will continue to evolve.

Telomere Length Dynamics and DNA Damage Responses Associated with Long-Duration Spaceflight

“…This milestone achievement ushered in a new era of spaceflight, one that aims to place the first woman and the next man on the Moon by 2024 and pioneer human exploration of Mars by the mid-2030s. Historically, a total of only 563 individuals have participated in spaceflight, the vast majority of whom have been males aged 35-55 years on missions shorter than 20 days duration (Smith et al, 2020). Thus, as the number and diversity of space travelers and tourists increase, a better understanding of how long-duration spaceflight affects human health is critical to maintaining astronaut performance during, and improving aging trajectories following, future exploration missions.…”

Temporal Telomere and DNA Damage Responses in the Space Radiation Environment

“…Marking a new era of human endeavors in space, NASA is planning to send the first woman and the next man to the moon by 2024 and is targeting human exploration of Mars by the mid-2030s. Historically, a total of only 563 individuals have participated in spaceflight, the vast majority of whom have been males aged 35-55 years (average age of first-time astronaut is 40 years), on missions shorter than 20 days in duration (Smith et al, 2020). As the number and diversity of people experiencing significantly longer duration spaceflight increase and ''space Cytogenetic analyses (metaphase chromosomes; T cells) for astronauts on 1-year or 6-month missions (n = 3).…”

The effects of long duration spaceflight on sensorimotor control and cognition

“…As age increases, sensorimotor adaptability declines (Seidler et al, 2010; Anguera et al, 2011). Astronaut training requires years to complete and the average age for an astronaut at the onset of their first mission is 39.8 (±5.28) years (Smith et al, 2020). It is important to consider the impact of age on behavioral and brain changes in spaceflight, thus we include age as a model covariate for exploratory purposes.…”