Large and impressive Litton SU-42/ASQ-119 'Astrotracker' astrocompass used for navigational purposes as part of the avionics suite mounted on General Dynamics FB-111A Aardvark aircraft. Designed to use starlight tracking, the compass has an internal gimbal and built-in collimator (an artificial star used for self-calibration) built by Davidson Optronics, a well-known manufacturer of precision optical systems used for alignment and testing. The housing bears an identification label, "SU-4/ASQ-119, Spec. No. ZE00084, Ser. 307, AF33(657)13403, Pt No. 668010-8, Mfr. 06481." It also bears an affixed Ogden Air Logistics Complex/Hill Air Force Base service tag indicating an overhaul date of May 10, 1983. An additional label identifies the "Tracker and Housing, Pt No. 668060-8, Ser. 1-207, Mfr. FSC06481, P/O SU-42/ASQ-119." The black collimator plate reads: "D681 Micro Collimator, Serial No. 33, Davidson Optronics, Inc." The unit measures approximately 14.5″ x 14.5″ x 12.5″, and has a green rubber protective cover for the glass panel.
This highly sophisticated automatic electromechanical astrocompass preceded GPS as a means for stellar navigation over long distances. Astrotrackers like the ASQ-119 could achieve extremely high accuracy but required expensive maintenance and a demanding calibration schedule. The ASQ-119 was fitted into the distinctive 'hump' on the upper nose of the F-111A Aardvark, a multirole combat aircraft primarily used by the United States Air Force and Royal Australian Air Force; it is also noteworthy that three preproduction F-111As were provided to NASA for various testing duties. This item is ITAR restricted; no export or sale to non-US citizens.
