Edited sentence: ASTRONAUT is a word in the dictionary meaning: a person who travels beyond the earth's atmosphere; also : a trainee for spaceflight Source: Merriam-Webster.COSMONAUT is a word on the dictionary meaning: an astronaut of the Soviet or Russian space program Source: Merriam-Webster.SPACE TURIST: is a NON EXISTENT word in the dictionary Source Merriam-Webster.To be absolutely clear on terms: