Astornauts have nothing to do with the American AstrOnauts.
Astornauts are the Chinese version of their American counterparts.

Originated on the site ChavScum.co.uk, used to describe the odd relationship allegedly inbred chavs have with other (male) members of their family.

Probably obviously, it derives from brother, uncle, and dad, and it has been quoted as "merely being uncle dad with 2 extra letters".

No-one, as of yet, has managed to figure out how a person might become brother, uncle, and father all to the same person.

A suitably humourous female counterpart has yet to be coined.

The instintanious stimulation of asian gland causing panic and euphoria resulting in a dispersal of all bodily fluids through all available escape routes