A person in a relationship who is being used for sex, friendship or comfort without receiving affection or love in return. Often, the non-astronaut food party is in an unhappy relationship.
The term refers to the packets of food astronauts use for nourishment without any taste or satisfaction.
The term comes from the book "You Don't Love Me Yet" by Jonathan Lethem.
She realized she was only his astronaut food, and didn't mean anything to him.
When you're puke drunk and making out with someone then you vomit uncontrollably into their mouth.
Guy 1: What happened with that chick you took into your room? She ran out fast. Guy 2: I gave her astronaut food.
A person who you are not in a relationship with but could always have the ability of being in a relationship. Much like astronaut food that person will never go stale or tired of waiting for their love to be requited.
Samantha: I am so lonely maybe I should just go out with Ian.
Francesca: yeah, he's your "astronaut food" , he's been in love with you for like 2 years!