400 SMS (PeaceKeeper era)	400 MS (Type1)	400 MS (Type2)
	90 DOTI-Peacekeeper	90 DOV-Peacekeeper
MX	MX Test Team	MX CALTP	MX G&C Rockwell Int'l

Development of the Peacekeeper, the LGM-118A, originally called Missile-X or MX, began in 1974, with a number of basing modes, mobile and fixed, considered. In 1981, the decision was made to deploy Peacekeeper in Minuteman silos, beginning with the 400SMS at Warren. The squadron became a Peacekeeper unit in 1986, and was operational until it was deactivated in 2005. Only 50 Peacekeepers were deployed. There are also a number of patches from the development and test programs.