As budgets tightened and public support for lunar missions faltered in 1970, NASA managers faced tough choices. On the one hand, the successful Apollo exploration missions had given lunar scientists an appetite for more and more samples - more, in fact, than even the six missions remaining on the schedule were likely to provide. Against that stood the need to get moving on post-Apollo programs, the first of which (Skylab) had reached a stage where it required substantial funds to stay on schedule. Given the unpalatable alternatives, NASA chose to cut back on lunar exploration and apply the savings to its future.1
1. U.S. Congress, House Committee on Science and Astronautics, 1971 NASA Authorization, Hearings on H.R. 15695, 91/2, Feb. 1970, vol. 1, pp. 2-38; W. David Compton and Charles D. Benson, Living and Working in Space: A History of Skylab, NASA SP-4208 (Washington, 1983), pp. 115-16.