 Minuteman III remains fitted with a single warhead due to the warhead limitations in New START.Beginning in 2005, Mk-21/W87 RVs from the deactivated Peacekeeper missile will be placed on the Minuteman-III force under the Safety Enhanced Reentry Vehicle (SERV) program.The older W78 does not have many of the safety features of the newer W87, such as insensitive high explosive, as well as more advanced safety devices.