
...a working PROTOTYPE of the Mars Rover.
The Big Bang Theory Season 8, Episode 3

Penny says they're having fun
working on the PROTOTYPE.
The Big Bang Theory Season 9, Episode 19

and took our PROTOTYPE and all of our
research and didn't even tell us?
The Big Bang Theory Season 10, Episode 23

but we did kinda have fun
working on the PROTOTYPE.
The Big Bang Theory Season 9, Episode 19

All right, I think we've got a PROTOTYPE
ready to test. Hand me that Tupperware.
The Big Bang Theory Season 2, Episode 22