technical support to the Pershing Operational Test Unit (POTU), identified problem areas and improved the performance and survivability of the Pershing systems. Gallery Pershing 1a Development In 1964 a series of operational tests and follow-on tests were performed to determine Pershing reliability. The Secretary of Defense then requested that the Army define the modifications required to make Pershing suitable for the Quick Reaction Alert (QRA) role. The Pershing 1a development program was approved in 1965, the original Pershing renamed to Pershing 1 and Martin Marietta received the Pershing 1a production contract in 1967. Project SWAP replaced all the Pershing equipment in Germany by mid-1970 and the first units quickly achieved QRA status. Secretary of Defense Robert McNamara directed that the U.S. Air Force's MGM-13 Mace missile would be replaced by the Pershing 1a in 1965. Pershing 1a was a Quick Reaction Alert system and so had faster vehicles, launch times and newer electronics. The total number of launchers increased from 8 to 36 per battalion. Production of the Pershing 1a missile ended in 1975 and reopened in 1977 to replace missiles expended in training. Pershing 1a was further improved in 1971 with the Pershing Missile and Power Station Development Program. The analog guidance computer and the control computer in the missile were replaced by a single digital guidance and control computer. The main distributor in the missile that routed power and signals was replaced with a new version. The missile used a rotary inverter to convert DC to AC that was replaced by a solid-state static inverter. The power station was improved for accessibility and maintenance. Further improvements in 1976 allowed the firing of a platoon's three missiles in quick succession and from any site without the need for surveying. The Automatic Reference System (ARS) used an optical laser link and a north-seeking gyro with encode to eliminate the need for pre-selected and surveyed points. The Sequential Launch Adapter connected the PTS to three missiles, eliminating the need to cable and uncable each launcher. A total of 754 MGM-31A missiles were built. Deployment The battalions in Europe reorganized under a new table of organization and equipment (TOE); an infantry battalion was added to provide additional security; and the 56th Artillery Group was reorganized and redesignated the 56th Field Artillery Brigade. Due to the nature of the weapon system, officer positions were increased by one grade: batteries were commanded by a