How to get paid overtime by not doing any extra hours. It's down to Relativity.
In Earth orbit, your clock slows down. Whereas on a Moon trip (away from Earth's gravitation) time speeds up.
According to Time.com (moreover, Einstein):
When Borman and Lovell were crewmates on the two-week orbital mission of Gemini 7, the time dilation effect was dominant for the entire period; the two astronauts thus aged less than those on earth by approximately 400 microseconds. Lovell's time also slowed down by about 100 microseconds during the four-day flight of Gemini 12.
Thus, during all their missions in space, Lovell and Borman respectively spent 200 and 100 microseconds less time than was recorded on earth—which means that they were paid for more time than they actually worked.
Read more: http://www.time.com/time/magazine/artic ... z0b6vMFqRF