Howard: I've been at this lab for three years, you've never came by to say hello.
Sheldon: Well, up until now I've had better things to do. So, what are we making today?
Howard: A small payload support structure for a European science experimental package that's going up on the next space shuttle.
Sheldon: Really, how does it work?
Howard: When this is done, it will be attached to the payload bay, and the sensor apparatus will rest on it.
Sheldon: Uh, huh. So it's a shelf?
Howard: No, you don't understand, during acceleration it needs to stay perfectly level and provide ... yeah, okay, it's a shelf.