Yep by reading it it does sound like a joke... and I know the astronauts joked around a lot. Apollo 16 is the best example of good natured astronauts having a good time on the moon but..

try listening to it on the ALSJ site... I'm not trying to make anything more out of it than what it is but I just found it a curious thing to say, and it doesn't sound like a joke .

Ah well...