Is this about the PROBE
he's working on without you?
The Big Bang Theory Season 8, Episode 21
The plaque they sent on the Pioneer PROBE
had a drawing of a naked man and woman.
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
Voyager the space PROBE,
or Voyager the Star Trek TV show?
The Big Bang Theory Season 8, Episode 6