I figure ray guns or phasers would be mandatory equipment on long term space flight.
They ought to be mandatory equipment for long term exposure to the religion forum.
I THINK I'm joking.
The Russians were way ahead of you.
The TP-82, ostensibly for predator defense after landing in the Siberian tundra:
http://en.wikipedia.org/wiki/TP-82
They also set up an automatic cannon in one of their military stations, Salyut 3:
http://en.wikipedia.org/wiki/Salyut_3