OPS 1166, also known by its OBJECT_ID 1981-019A, is a KH-8 satellite launched on February 28, 1981, from AFWTR Launch Site at SLC4W using the Titan 24B launch vehicle. The satellite has dimensions of 5.7 meters in length and diameter with a span of 5.7 meters. It weighs 2400 kilograms both at launch and dry mass. Equipped with two deployable solar arrays and batteries for power, its mission is reconnaissance focused on photographic film return type operations. Manufactured by LMSC for the NRO/SAFSP, it carries the GAMBIT-3 FM-51 payload and has a Bell 8096 SPS motor. The satellite's shape is cylindrical with an RCS of 7.37 square meters and was operational for 75 days.