Force Systems Command, 15 October 1961 Redesignated: 22nd Space Operations Squadron, 1 June 1997 Redesignated: Det 3, 22d Space Operations Squadron, 1 May 2004 Redesignated: Det 1, 23d Space Operations Squadron, 1 October 2010 – present 12th Missile Warning Group, 31 March 1977 Redesignated: 12th Missile Warning Squadron, 15 June 1983 Redesignated: 12th Missile Warning Group, 1 October 1989 Redesignated: 12th Space Warning Squadron, 15 May 1992 – present 4711th Air Base Squadron, 31 March 1977 Redesignated: 4685th Air Base Squadron, 1 October 198031 March 1981 821st Air Base Group, 1 June 2002present Major Army units assigned 4th Battalion, 55th Artillery, 1 Sep 195820 Dec 1965. (Nike) 7th Anti-Aircraft Artillery Group, 1 July 1955 – 20 December 1965 (Redesignated 7th Artillery Group 20 March 1958) [A, B, C, and D Batteries 90mm AAA cannon; 549th 75mm AAA BN (Sky Sweeper); 51st Ordnance Company] Remote tracking station Thule Tracking Station (TTS) is operated by Thule Air Base, using the callsign POGO. The station ) is a U.S. Space Force installation in Greenland, near the base, and has a Remote Tracking Station (callsign: Polar Orbiting Geophysical Observatory (POGO)) of the Satellite Control Network. It was originally the classified 6594th Test Wing's Operating Location 5 designated by Air Force Systems Command on 15 October 1961: the station was operational on 30 March 1962, with "transportable antenna vans parked in an old Strategic Air Command bomb assembly building." The permanent RTS equipment was emplaced in 1964, and a communications terminal was emplaced on Pingarssuit Mountain—Thule Site N-32 (moved to Thule Site J in 1983. Accidents In 1954 a Douglas C-124C Globemaster II operated by the US Air Force crashed on approach to the air base, killing ten people. B-52 nuclear bomber crash (1968) On 21 January 1968, a B-52G Stratofortress from the 380th Strategic Aerospace Wing, Plattsburgh Air Force Base, New York, on a secret airborne nuclear alert crashed and burned on the ice near Thule Air Base. The impact detonated the high explosives in the primary units of all four of the B28 nuclear bombs it carried, but nuclear and thermonuclear reactions did not take place due to the PAL and fail-safe mechanisms in the weapons, thus preventing the actual detonation of the weapons themselves. The resulting fire caused extensive radioactive contamination. More than 700 Danish civilians and US military personnel worked under hazardous conditions, the former without protective gear, to clean up