Astronaut

An astronaut is a person trained and equipped to serve as a commander or crew member of a spacecraft.

The term comes from Ancient Greek words meaning "star sailor." While usually used for professionals, the word sometimes describes scientists, politicians, or space tourists. In the United States, NASA, the FAA, and the military use it as a specific designation.

Different agencies have different rules for who earns this title. NASA and the military apply it to their own employees who meet specific criteria. The European Space Agency uses the term for graduates of its astronaut training program.

How we define "space" changes how we name these travelers. The FAI Sporting Code recognizes spaceflight only above the Kármán line. This is an altitude of 100 kilometers. In the United States, professional, military, and commercial astronauts receive wings if they fly above 80 kilometers.

Some people focus on where aerodynamic force ends and centrifugal force takes over. This transition happens as the atmosphere becomes very thin. These scientific boundaries help determine who officially qualifies as a space traveler.

Different nations use unique names for their space crews.

In Russia and the former Soviet Union, travelers are called cosmonauts. This comes from the Russian word "kosmos," meaning space. China uses the term taikonaut for its professional travelers. This word comes from the Mandarin word "tàikōng," which also means space.

In China, official staff are called hángtiānyuán, or "celestial navigators." Other terms like "spationaut" for French travelers or "vyomanaut" for proposed Indian missions also exist.

History shows how these naming debates began. In 1959, NASA leaders discussed whether to use "astronaut" or "cosmonaut."

Deputy Administrator Hugh Dryden preferred "cosmonaut" because it suggested flight into the broad cosmos. However, most NASA members preferred "astronaut." This term survived through common usage in America. The Soviet Union chose "cosmonaut" when Yuri Gagarin became the first human in space in 1961.

Valentina Tereshkova later became the first and youngest woman to fly solo in 1963.

Spaceflight has changed significantly over time. Until 2002, only governments sponsored and trained astronauts. This included the military and civilian space agencies. In 2004, the suborbital flight of SpaceShipOne created a new category: the commercial astronaut.

Today, NASA and the Russian Federal Space Agency use the term "spaceflight participant" for non-professionals. This helps distinguish tourists from the professional crew members on coordinated missions.

Many people have reached incredible heights and durations in space. As of 2021, 600 astronauts had flown in space.

In the United States, 558 people have reached an altitude above 80 kilometers. Only 24 people have traveled beyond low Earth orbit. Three men, Jim Lovell, John Young, and Eugene Cernan, traveled that far twice. Space travelers have spent over 41,790 man-days in space. Oleg Kononenko holds the record for most time in space with over 1,100 days. Peggy A. Whitson holds the record for women with 675 days.

Astronauts connect many different fields of science and human effort. Their work involves complex training and specialized equipment to survive the vacuum of space. They perform spacewalks to maintain spacecraft, totaling over 100 astronaut-days.

This work requires cooperation between different nations and private companies. As technology advances, the definition of an astronaut continues to evolve. The field moves from government-only missions toward a broader era of commercial and international space exploration.