The 6555th Aerospace Test Group is an inactive United States Air Force unit. It was last assigned to the Eastern Space and Missile Center and stationed at Patrick Air Force Base, Florida; it was inactivated on 1 October 1990. Prior to the activation of Air Force Space Command, the unit was responsible for the development of USAF missiles, including tactical surface-to-surface missiles, the CIM-10 Bomarc interceptor, the SM-62 Snark intercontinental cruise missile, intercontinental ballistic missiles, and heavy launch rockets for military and satellite deployment. The unit played a key role in the civilian NASA programs Project Mercury, Project Gemini, and Project Apollo, as well as in military Space Shuttle flights. The unit's mission is now performed by the 45th Space Launch Delta, although there is no direct lineage. Activated in December 1950 to replace the 550th Guided Missiles Wing, the 6555th had a distinguished career launching and managing ballistic missiles, space launch vehicles, and payloads for the Ballistic Systems Division, the Space Systems Division, and the Space and Missile Systems Organization. As a wing or a group, the 6555th earned ten Air Force Outstanding Unit Awards between 21 December 1959 and October 1990. In the 1950s the unit underwent several designation changes and organizational realignments; as launches of winged missiles continued, the wing gained two new units: the 1st Pilotless Bomber Squadron in October 1951 and the 69th Pilotless Bomber Squadron in January 1952. Thereafter, the 6555th focused on assembling, testing, and launching B-61 Matador missiles to prepare the 1st and 69th Pilotless Bomber Squadrons for operations in Europe. The 6555th Guided Missile Wing became the 6555th Guided Missile Group on 1 March 1953, and the 1st and 69th Pilotless Bomber Squadrons were reassigned to Tactical Air Command (TAC) on 15 January 1954. Because TAC agreed to train all other B-61 Matador squadrons at its school in Orlando AFB, Florida, the 6555th Guided Missile Group was reduced to little more than a squadron when the 69th completed field training in the summer of 1954. The 6555th Guided Missile Group was discontinued on 7 September 1954. The 6555th Guided Missile Squadron continued as a B-61 Matador research and development testing unit and was reassigned to AFMTC Headquarters on 7 September 1954. The 6555th Guided Missile Squadron became the 6555th Guided Missile Group (Test and Evaluation) on 15 August 1959 and was reassigned to the Air Force Ballistic Missile Division on 21 December 1959 without a change of station; concurrent with the reassignment, the group absorbed the resources of the Division's Assistant Commander for Missile Tests. At the beginning of 1971, the 6555th Aerospace Test Group consisted of a commander's office and three divisions: Support, Atlas Systems, and Titan III Systems. Although the Test Group's launch operations in the early 1970s centered on the Atlas and Titan III systems, the Group established a Space Transportation System (STS) Division on 1 July 1974 to ensure the Department of Defense's Shuttle requirements were incorporated into future Shuttle operations at Kennedy Space Center (KSC). On 1 November 1975 the Group reorganized its Atlas and Titan III launch agencies into a Space Launch Vehicle Systems Division and simultaneously consolidated the Atlas Satellite Launch Systems Branch and the Titan III Space Satellite Systems Launch Operations Branch into a newly created Satellite Systems Division. The 6595th Aerospace Test Wing commander directed these changes to place booster operations under one division chief and payload operations under another. The IUS Operations Branch was placed under the Space Launch Vehicle Systems Division when it was formed on 1 July 1977. After the final Atlas-Agena launch on 6 April 1978, the Space Launch Vehicle Systems and Satellite Systems divisions shifted focus from Atlas-Agena operations on Complex 13 to Atlas-Centaur boosters and Department of Defense payloads on Complex 36. On 1 October 1979 the Group was transferred to the Eastern Space and Missile Center (ESMC), the immediate predecessor of the 45th Space Wing. The unit was inactivated on 1 October 1990 when Air Force Space Command inactivated the provisional unit and merged its organization with ESMC. Most of the 6555th's resources were reorganized as the 1st Space Launch Squadron under ESMC and two Combined Task Forces (CTFs) serving AFSPC and Air Force Systems Command. Ultimately, the last vestiges of the 6555th were inactivated on 1 July 1992 as Air Force Systems Command and Air Force Logistics Command merged to form Air Force Materiel Command. Today, the mission is performed by components of the 45th Space Wing: the 45th Operations Group and the 45th Launch Group.

Weapons and missile development — Postwar era

Between 1946 and 1950, the group's predecessor units, the 1st Experimental Guided Missiles Group and the 550th Guided Missiles Wing, tested a variety of glided bombs and tactical missiles. They also developed QB-17 drone aircraft for use in atomic bomb testing and later as targets for anti-aircraft missiles. The 550th GMW also launched the first rockets from the Joint Long Range Proving Ground at Cape Canaveral, Florida, in 1950.

Republic-Ford JB-2 (1947–1949)

The JB-2 was a U.S.-made copy of the German V-1 surface-to-surface, pilotless flying bomb first used against England in June 1944. Planned for use in the invasion of Japan, the missile was never used in combat during World War II. The 1st Experimental Guided Missiles Group began testing the JB-2 at White Sands, New Mexico, in March 1947 and spent several months preparing a detachment for cold‑weather testing in Alaska in November 1948. Testing was also conducted at the Army Air Forces Proving Ground on Santa Rosa Island, Florida. The JB-2 was never used operationally, but it led to the development of the USAF’s first operational cruise missile, the Martin B-61A Matador.

QB-17L/BQ-17 Flying Fortresses (1946–1950) were unmanned aircraft used to fly near or even through mushroom clouds during postwar atomic tests. B-17s were withdrawn from storage for conversion into drones with the addition of radio, radar, television, and other equipment. Most of the conversions were performed by the San Antonio Air Depot at Kelly Field, Texas.