[1] astronaut (US); cosmonaut (Russia) - a person who has travelled to, or is in, outer space in some form of spacecraft; sometimes referred to as a "taikonaut" but this is actually a term coined by the Western media taking the Mandarin pronounciation of 太空 (tai4 kong1) appended to the Greek root -naut meaning sailor/navigator; China prefers to use the term 航天員 instead.
[2] refers to an emigre from Hong Kong who maintains business ties to Hong Kong and thus spends a lot of time "in the air" flying back and forth between Hong Kong and the place in which they settled.