Because it was a "race" between the USSR and the US to reach space milestones first.
He or she is called an 'astronaut' regardless of his or hergender identification, affiliation, history, or preference.
Travelers of Space was created in 1951.
Travelers of Space has 400 pages.
Space Travelers - 2009 was released on: USA: July 2009
The cast of Space Travelers - 2009 includes: Burt Rutan as himself George Takei as himself
Some 493 space travelers are known.
The Space Shuttle
There were at least 40 travelers.