The Arecibo Ionospheric Observatory is a radio and radar telescope located on approximately 120 acres of federally owned land in Barrio Esperanza, Arecibo, Puerto Rico. Currently, the Arecibo Observatory is managed, operated, and maintained by SRI International. (SRI International partners with the Universities Research Association, and the Universidad Metropolitana, San Juan, and the University of Puerto Rico). Built in a natural depression in the jungles of Puerto Rico, Arecibo is the world's largest single-dish radio-wavelength reflector, measuring approximately 1,000 feet across and 167 feet deep. The 900-ton receiver platform is suspended 450 feet above the reflector dish. The 40,000 aluminum panels of the structure cover 20 acres. Arecibo can receive signals from 25 megahertz to 10 gigahertz. Transmitters include an S-band 2,380-megahertz radar system for solar studies and a 430-megahertz radar system for ionospheric studies. Arecibo can access approximately 40.0% of the sky and "has an unrivalled sensitivity due to its large size." The fixed spherical telescope has the ability to predict and track the movement of potentially hazardous near-Earth objects. Construction of the Arecibo Observatory began in 1960 at the initial cost of $9.7 million. The Defense Department's Advanced Research Projects Agency provided funding for the project, the Air Force administered it, and Cornell University managed the project for the Air Force. Arecibo was commissioned for service on November 1, 1963. Initially designed for radar studies of Earth's ionosphere, it was also found to be valuable for research in radio and radar astronomy. In 1970, ownership of Arecibo was transferred from the Department of Defense to the National Science Foundation's (NSF) Division of Astronomical Sciences (AST), with NSF subsequently taking responsibility for funding of the telescope. It was at this time that the NAIC was established at Cornell University to manage the facility. The telescope has evolved and developed over its lifetime. In 1974, the first upgrade was completed, replacing the original wire mesh surface with aluminum panels. The upgrade totaled approximately $8.0 million—approximately $5.0 million from NSF and $3.0 million from National Aeronautics and Space Administration (NASA). The upgrade enabled Arecibo to operate at 3 gigahertz. Also, planetary radar studies were expanded with the installation of a 420 kilowatt transmitter, operating at 2.4 gigahertz. In 1997, the second upgrade of the facility was completed, with the installation of a Gregorian reflector system, suspended approximately 450 feet above the telescope's 1,000-foot dish and a 1-megawatt radar transmitter. This upgrade allowed the telescope to operate at up to 10 GHZ, increasing the telescope's "sensitivity, frequency coverage, and agility, and enabl[ing] dual-beam incoherent scatter radar capability, providing new research opportunities." The upgrade was undertaken by NSF and NASA, with support from Cornell University, at a cost of $25.0 million—$14.0 million from NSF and $11.0 million from NASA. Arecibo is recognized for its research in radio astronomy, solar system radar astronomy/planetary radar, and ionospheric observations/terrestrial aeronomy. It has been used for research in such diverse areas as interstellar gas, pulsars and fundamental physics, variations in Earth's ionosphere, galactic structure formation and evolution, complex and pre-biotic molecules in the interstellar medium, planetary surfaces and moons, and the post-discovery characterization and orbital refinement of near-Earth asteroids. One of the first accomplishments of Arecibo was determining the correct rotation rate of Mercury, which was found to be 59 days instead of the previously estimated 88 days. Other Arecibo firsts include the first discovery of a binary pulsar, the first discovery of planets outside the solar system, and the first detailed three-dimensional mapping of how galaxies are distributed in the universe. In 1982, research conducted at Arecibo discovered a type of radio emission—hydroxyl megamaser—that has since been found to indicate a collision between two galaxies. In 1997, the Board on Physics and Astronomy of the National Research Council (NRC) established the Astronomy and Astrophysics Survey Committee to assess the field of ground- and space-based astronomy and astrophysics for the decade 2000 to 2010. The committee was charged with recommending priorities for initiatives during that decade and to explore areas of development of new technologies. The report of the 2000 decadal survey, Astronomy and Astrophysics in the New Millennium, made an effort to find the balance between long-term support for facility operations and research grants and priority for new technological opportunities and facilities. The committee made recommendations relating to coordination of the astronomy and astrophysics programs of the NSF, NASA, and the Department of Energy Office of Science (DOE). The committee also explored possibilities for international collaboration and private, state, and federal partnerships. The decadal survey recommended that NSF conduct competitive review of its astronomy facilities and organizations approximately every five years. Another report of the NRC, Connecting Quarks with the Cosmos , proffered recommendations that paralleled those of the decadal survey. Both noted that AST should respond to emerging scientific opportunities and construct different operational models for future astronomy facilities and organizations. The 2008 annual report of the federal Astronomy and Astrophysics Advisory Committee mirrored many of the recommendations contained in the 2000 decadal survey and Connecting Quarks with the Cosmos . It stated that AST's focus must of necessity change to reflect the needs of these new, powerful and very expensive facilities. A robust program of support for the majority of our current facilities, combined with the operations funding needed for our new and immensely more powerful facilities…, mandate cuts in funding for some current facilities if we are to make a credible case for new funding! The report suggested that in order to bring long-term stability to Arecibo for the science community, alternative funding sources and partnerships should be explored with other institutions in Puerto Rico and possibly with support from NSF's Division of Atmospheric Sciences. It was suggested also that international partnerships should be explored. In a joint NSF-NASA response to the committee, it was noted that although partnerships and joint projects can be problematic by increasing managerial complexity, they do offer the benefit of sharing responsibility and authority. A January 2010 report of the National Research Council examined near-earth objects (NEOs) and hazard mitigation strategies. Included in this report was an analysis of the costs of detecting potentially hazardous NEOs and the costs associated with mitigation efforts. The survey sought to determine the role the Arecibo would have in detecting, tracking, and characterizing NEOs. One of the findings in the report was that The Arecibo and Goldstone radar systems play a unique role in the characterization of NEOs, providing unmatched accuracy in orbit determination, and insight into the size, shape, surface structure, and other properties for objects within their latitude coverage and detection range. The report further recommended that Immediate action is required to ensure the continued operation of the Arecibo Observatory at a level sufficient to maintain and staff the radar facility. Additionally, NASA and NSF should support a vigorous program of radar observations of NEOs at Arecibo and NASA should support such a program at Goldstone for orbit determination and characterization of physical properties. The current decadal survey, addressing the period 2010-2020, was released in August 2010— New Worlds, New Horizons in Astronomy and Astrophysics . This survey provides a comprehensive and robust review of strategic planning process. In addition, it explores interagency issues among NSF's AST, NASA's Astrophysics Division, and DOE's Office of Science, High Energy Physics. The committee for this survey, known as Astro2010, was directed to make its recommendations and considerations for funding levels for astronomical research based on limited resources and a flat budget trajectory. This survey included prioritization of "unrealized projects from previous decadal surveys that had not had a formal start alongside new research activities that had emerged from the research community." The report recommended that NSF-Astronomy should complete its next senior review before the mid-decade independent review that is recommended elsewhere in this report, so as to determine which, if any, facilities NSF-AST should cease to support in order to release funds for (1) the construction and ongoing operation of new telescopes and instruments, and (2) the science analysis needed to capitalize on the results from existing and future facilities. In 2005-2006, NSF's AST conducted a Senior Review of its portfolio of facilities. This review resulted from a combination of factors—projections for federal spending on research and development, growth of the AST budget, the proposed directions of the astronomical research community, and the recommendations and analyses contained in the aforementioned reports on ground-and space-based facilities. The Senior Review was to, among other things, identify potential reinvestment in the highest priority existing programs in AST and to restructure the operational efficiency of the existing AST-operated facilities. The Senior Review examined the balance within the full portfolio of projects and recommended changes that would provide savings from existing programs to be redirected in support of new activities. The Senior Review stated that Arecibo continues to produce scientific results, but when budgets are limited, choices have to be made to explore new science opportunities and new capabilities. The committee reported that the scientific value of the telescope was modest when compared to other existing and proposed projects funded primarily by the NSF. NSF has stated that Identifying potential cost savings in our current portfolio of projects and devising an acceptable implementation plan for realizing these savings will allow progress to be made on the next generation of Astronomical instruments and better position AST for future budget augmentation. The Senior Review determined that the approximately $200.0 million astronomy budget was facing a deficit of $30.0 million by 2010.