astronaut

An astronaut is the one trained to serve as a crew member of a space mission.Usually this term is also used for a person who travels in the space.

Starting in the 1950s up to 2002, astronauts were sponsored and trained exclusively by governments, either by the military or by civilian space agencies. With the suborbital flight of the privately funded Space Ship One in 2004, a new category of astronaut was created: the commercial astronaut the criteria for what constitutes human spaceflight vary. The Federation Aéronautique Internationale (FAI) Sporting Code for astronautics recognizes only flights that exceed an altitude of 100 kilometers (62 mi). In the United States, professional, military, and commercial astronauts who travel above an altitude of 50 miles (80 km) are awarded astronaut wings.

As of 8 June 2013, a total of 532 people from 36 countries have reached 100 km (62 mi) or more in altitude, of which 529 reached low Earth  beyond. Of these, 24 people have traveled beyond Low Earth orbit, to either lunar or trans-lunar orbit or to the surface of the moon; three of the 24 did so twice: Jim Lovell, John Young and Eugene Cernan. The three astronauts who have not reached low Earth orbit are space plane pilots Joe Walker, Mike l, and Brian Binnie.

As of 20 June 2011, under the U.S. definition 538 people qualify as having reached space, above 50 miles (80 km) altitude. Of eight X-15 pilots who exceeded 50 miles (80 km) in altitude, only one exceeded 100 kilometers (about 62 miles) Space travelers have spent over 41,790 man-days (114.5 man-years) in space, including over 100 astronaut-days of spacewalks. As of 2008, the man with the longest cumulative time in space is Sergei K. Krikalev, who has spent 803 days, 9 hours and 39 minutes, or 2.2 years, in space.Peggy A. Whitson holds the record for the most time in space by a woman, 377 days