doctorbadwolf
Heretic of The Seventh Circle
It's not even kinda a little bit vaguely equivalent, nor is it at all ludicrous.Outside if a NASA themed rpg it's kinda ludicrous.
DM might be running a Tour of Duty RPG in Vietnam. Astronaut training didn't involve being sent to the frontlines although you might be able to go the other way if you're a pilot in Nam.
It's roughly equivalent to PCs wanting to be king or emperor in their background.
If the campaign is Vietnam based, in the real world, not an analogous world, sure. You can usually come up with a mutually exclusive campaign to rule out a background. Taking place far away doesn't qualify.