Since the postwar period, these OSPs in astronomy have been common U.S.
practice, and while they have mostly been ius non scriptum, they have been alluded to in reports of the NSF's Division of Astronomical Sciences, 8 and largely followed by federally funded agencies (NASA's Hubble Space Telescope, for example, among the most
expensive U.S. astronomical
facilities, 9 is open to any astronomer in the world10).