what is the meaning of caustronaut?

I've seen in mantram s profile that he is a future CAUSTRONAUT. Now don't tease me or something, I did search in Google but it didn't work so I'm asking. Mantram blocked me right so I can't directly ask. So WITHOUT shaming me please anyone help..

Astronaut.

An astronaut who eat cashew nuts

Cosmologist+Astronomer+Astronaut= Caustronaut.

(As far as I know).

Thanks guys

claustrophobic guy who dreams about being an astronaut.

A Catastophe?

Next week: Castratonauts.

May as well go out on a high note.

castrated astronaut?