Season 5 Episode 15
In this episode, Leonard and Sheldon’s friendship is pushed to the limit when Sheldon finally goes too far. The episode starts with Sheldon waking Leonard up in the middle of night with a post apocalyptic drill. This leads to the friendship agreement being expunged along with the friendship between the two being stripped to nothing more than roommates. While this drama is going on, Wolowitz finally gets his astronaut nickname (fruit loops), after an unfortunate happenstance with a meet and greet over skype with an astronaut.
This astronaut being none other than the famous Michael J Massimino.
Michael James Massimino (born August 19, 1962) is an American engineer and a NASA astronaut. Mike is a veteran of two Space Shuttle missions, both of which serviced the Hubble Space Telescope (HST), including the historic final repair mission.