So, when the aliens brought you back,
they just left the PROBE in?
The Big Bang Theory Season 9, Episode 23
- The space PROBE.
- Good.
The Big Bang Theory Season 8, Episode 6
Is this about the PROBE
he's working on without you?
The Big Bang Theory Season 8, Episode 21
He helped launch the
New Horizons space PROBE.
The Big Bang Theory Season 12, Episode 5
And, of course, it's Gravity Probe B.
The Big Bang Theory Season 1, Episode 13