That wasn't a prank, though
It was a science experiment.
The space program participants participated in many pranks, including
and especially the astronauts.
As just one example, during the Gemini 6 and 7 rendezvous in late 1965,
one ship crew put a sign that said Beat Army in its tiny cockpit window
to tease a member of the other ship. It was in an issue of National
Geographic magazine.