An astronaut is a person who has been trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft. Although generally reserved for professional space travelers, the term has sometimes been applied to anyone who travels into space, including scientists, politicians, journalists, and tourists.
The first human to travel into space was Yuri Gagarin of the Soviet Union in 1961. Alan Shepard of the United States became the first American in space later that same year. Since then, over 550 people from 38 countries have traveled into space. China sent its first taikonaut into orbit in 2003. As of 2020, only around 60% of astronauts have been men while 40% have been women. The vast majority (93%) have been white while just 5% have been Asian and 1% black . There are currently no Native American or Pacific Islander astronauts.
Education and training requirements for astronauts vary depending on which country’s space agency they wish to join as well as the specific role or mission they hope to undertake. However, all candidates must undergo rigorous physical and mental tests before being accepted into any astronaut training program. In general, successful applicants will have experience flying jets and possess advanced degrees in science or engineering . Some programs also require prior experience working in hazardous environments such as undersea oil rigs .
After being selected for training, astronauts typically spend several years learning about spacecraft systems and undergoing various simulations before finally being cleared for their first mission . During this time they may also be required to complete grueling physical conditioning exercises to prepare them for the rigors of living and working in microgravity conditions .
Astronauts play an important role in conducting research during their missions aboard the International Space Station (ISS). They are responsible for conducting experiments in many different fields such as biology , physics , astronomy , and materials science . The unique environment of microgravity allows researchers on Earth to study phenomena that cannot be easily replicated under normal gravity conditions . This research helps further our understanding of both Earth-based sciences as well as those related to extraterrestrial life .
In addition to conducting research , astronauts also work on maintenance tasks during their time on the ISS. They are responsible for repairing equipment , checking fluid levels , lubricating moving parts , installing new hardware , and performing other routine maintenance tasks . These activities keep the ISS running smoothly so that it can continue to support future research missions .
Astronauts return back home after completing their mission where they share their experiences with friends , family members , colleagues , students , and others interested in learning about life in space . Many go on to write books or give lectures about their time spent living and working off planet Earth . Some even become celebrities due largely to their unique occupation !