"In 2011 NSF's Division of Astronomical Sciences (AST) commenced a Portfolio Review process in order to review the entire portfolio of AST-supported facilities, programs and other activities. The goal of the review was to recommend to AST how support for existing facilities, programs, and activities should be prioritized and interleaved with new initiatives recommended by the National Academy of Sciences decadal surveys, within the limitations of realistic future budgets."
"AUI and NRAO have made a preliminary examination of the report released today from the NSF Astronomy Portfolio Review Committee (PRC). Among the recommendations of that report are that the NSF's Green Bank Telescope and Very Long Baseline Array be fully divested from the NSF Astronomy Division's portfolio of research facilities in the next five years, with no further funding from the Astronomy Division. AUI and NRAO recognize and acknowledge the need to retire obsolete facilities to make way for the state-of-the-art. However, both the GBT and the VLBA are the state-of-the-art, and have crucial capabilities that cannot be provided by other facilities. Separately the two telescopes provide unparalleled scientific access to the universe. When their information is combined, the instruments provide the highest sensitivity and resolution available for any astronomical instrument in the world."