The United States Naval Observatory Flagstaff Station (NOFS), is an astronomical observatory near Flagstaff, Arizona, USA. It is the national dark-sky observing facility for the U.S. Department of Defense, under the United States Naval Observatory (USNO). NOFS and USNO combine as the Celestial Reference Frame manager for the U.S. Secretary of Defense.
The USNO and NOFS are commands within the CNMOC claimancy, the latter which serves the U.S. Navy on meteorological and oceanographic matters in addition to overseeing astronomical ones. The Flagstaff Station is a command which was established by USNO (due to a century of eventually untenable light encroachment in Washington, D.C.) at a site five miles west of Flagstaff, Arizona in 1955, and has positions for 35 scientists (astronomers and astrophysicists), optical and mechanical engineers, and support staff.
It is currently manned at 20 personnel. Its principal mission is to provide the military and others extremely accurate, ground-based astrometry (defined as the positions of celestial and artificial space objects), Celestial mechanics (dynamical motions of celestial objects) and photometry (defined as brightness variations, often in terms of 'color') – in the form of million-to-billion-star catalogs for a wide diversity of U.S. global (and spaceborne) position and navigation interests.
The NOFS staff is organized into four divisions: Optical/Infrared, Engineering & Site Operations, Digital Catalogs, and Navy Precision Optical Interferometer(NPOI) Divisions. Additional management staff members serve executive, IT (computer LAN/systems), fiscal, administrative, and facilities functions.NOFS is the U.S. Navy's National Dark Sky Site, and is responsible for the bulk of the 'astrometric component' of the U.S. DoD and national Position-Navigation-Time (PNT) mission.
The United States Naval Observatory, Flagstaff Station celebrated its 50th anniversary of the move there from Washington, D.C. in late 2005.Each autumn, NOFS opens its doors annually to the public, during the Flagstaff Festival of Science.In 2009, visitor attendance topped 710.NOFS remains active in supporting regional dark skies, both to support its national protection mission, and to promote and protect a national resource legacy for generations of humans to come.
Kaj Strand Telescope:
Congressionally appropriated in 1961, the 61-inch Kaj Strand Telescope (or 1.55-m Kaj Strand Astrometric Reflector, KSAR) remains largest telescope operated by the U.S. Navy since it saw first light in 1964.This status will change when the NPOI four 1.8-meter telescopes see their own first light in the near future. KSAR rides in the arms of an equatorial fork mount.The telescope is used in both the visible spectrum, and in the near infrared (NIR),the latter using a sub-30-Kelvin, helium-refrigerated, InSb (Indium antimonide) camera, "Astrocam".
1.3 m telescope:
The 1.3 m (51-inch) large-field R-C telescope was initially produced by DFM Engineering and then corrected and automated by NOFS staff. Corning Glass Works and Kodak made the primary mirror. The hyperbolic secondary has an advanced, computer-controlled collimation (alignment) system in order to permit very precise positions of stars and satellites (milli-arcsecond astrometry) across its wide field of view. This system analyzes optical aberrations of the optical path, modeled by taking slope fits of the wavefront deviations revealed using a Hartmann mask.
1.0 m telescope:
The 40-inch (1-meter) "Ritchey Telescope" is also an equatorially driven, fork-mounted telescope. The Ritchey is the original Station telescope which was moved from USNO in Washington in 1955. It is also the first R-C telescope ever made from that famous optical prescription, and was coincidentally the last telescope built by George Ritchey himself. The telescope is still in operation after a half century of astronomy at NOFS.
0.2 m FASTT:
A modern-day example of a fully robotic transit telescope is the small 0.2m (8 in) Flagstaff Astrometric Scanning Transit Telescope (FASTT) located at the observatory.FASTT provides extremely precise positions of solar system objects for incorporation into the USNO Astronomical Almanac and Nautical Almanac.These ephemerides are also used by NASA in the deep space navigation of its planetary and extra-orbital spacecraft. Instrumental to the navigation of many NASA deep space probes, this telescope is responsible for NASA JPL's successful 2005 navigation-to-landing of the Huygens Lander on Titan, a major moon orbiting Saturn, and is currently providing navigational reference for NASA's New Horizons deep space mission to Pluto, slated to arrive at the edge of the Solar System in July 2015.