W. Patrick McCray’s article “The Contentious Role of a National Observatory” (Physics Today, Physics Today 0031-9228 5610200355 https://doi.org/10.1063/1.1629005October 2003, page 55 ) describes the tension between two important individuals as the US national optical observatory system was formed. Some of the reasons behind that tension need to be emphasized—in particular, the influence that NSF had on the money trail. As an astronomer, I worked with Leo Goldberg at the University of Michigan, helped for a dozen years to build a nationally funded observatory, and worked with Jesse Greenstein, who advised me about investments when I was treasurer of the American Astronomical Society; I also am a former director of the astronomy division at NSF. In all these positions, I was privileged to both witness firsthand and participate in NSF’s support for astronomy.

In the 1950s, astronomers in the upper Midwest and in the East had access only to small telescopes located in poor observing climates; the large state- and endowment-funded telescopes in the West served small staffs of excellent astronomers who offered little observing time or support to visitors. It was the Midwest astronomers, soon joined by the Easterners, who convinced NSF to provide national funding for moderate-to-large optical telescopes on Kitt Peak. Those facilities would encourage visitors and be competitively available to anyone with a good observing program. Had the large western telescopes been more accessible to visitors, the funding history might well have evolved differently.

Although western astronomers complained that monies that should have gone to them were going to the new national observatory, they soon became board members of the Association of Universities for Research in Astronomy, which manages Kitt Peak National Observatory. But as McCray points out, they often took positions that served to cap further growth of Kitt Peak.

A primary goal of NSF is to assure the scientific health of each sub-branch of each science it funds. Within the constraints of available money, NSF’s funding for ground-based astronomy has supported that goal well. Its initial perception that optical astronomers needed more access to larger telescopes prompted the formation of Kitt Peak. Its experience with the reticence of western observatories to open their telescopes to visitors who had excellent observing programs served to stimulate initial federal support for a national optical observatory. Some funding was available to build modest national telescopes but not to build still larger telescopes for private and state universities. NSF could not do both, although it was able to fund instrumentation for those observatories.

Up to the late 1970s, there was an unwritten agreement, monitored by the Office of Management and Budget, that NSF would fund ground-based astronomy and NASA would fund US space observatories and the space-oriented programs associated with them. But after the mid-1970s, NASA began to fund construction of ground-based telescopes and provide more broadly defined ground-based support. That shift has tended to erode the role of the ground-based astronomy program at NSF. Any decrease by NASA in funding for ground-based activities without a commensurate increase in NSF’s program would have a serious negative effect on the nation’s research contributions to astronomy.

Throughout its history, NSF’s astronomy program has been responsible for assuring the health of the entire ground-based enterprise in the US by providing a balance among its grantees, its instrumentation programs, its centers, and all astronomical subdisciplines. Moreover, NSF strives to ensure, through cooperative programs with other nations, that the US will remain internationally competitive. To do this, it takes into account the degree of funding from other sources and uses its limited funds to achieve a good national balance.

NSF’s purpose was never to make the national optical observatories dominant; the organization has always taken steps to ensure that only excellent research is pursued at places that receive federal funding. NSF officials are still trying with some success to give visitors greater access to those observatories that are not primarily nationally funded.