warheads were developed for the missile: the W87-1 warhead in a Mark 21 re-entry vehicle with a yield of , and the W61 earth penetrating warhead with a yield of . Carrier vehicle: Hard Mobile Launcher The Midgetman was to be carried by an eight-wheel drive Hard Mobile Launcher (HML) vehicle. Most of these vehicles would normally remain on bases, only being deployed in times of international crisis when nuclear war was considered more likely. The Hard Mobile Launcher was radiation hardened and had a trailer mounted plow to dig the HML into the earth for additional nuclear blast protection. Cancellation With the end of the Cold War in the 1990s the U.S. scaled back its development of new nuclear weapons. The Midgetman program was therefore cancelled in January 1992. The legacy of its lighter graphite-wound solid rocket motor technology lived on in the GEM side boosters used on the Delta rockets, and the Orion stages of the Pegasus air-launched rocket. The Soviet equivalent of this missile was the RSS-40 Kuryer which was tested but cancelled in October 1991. This could have filled the role of the more cost effective Topol M road mobile ICBM. See also Nuclear warfare Nuclear weapon Intercontinental ballistic missile List of missiles References Further reading External links http://www.designation-systems.net/dusrm/m-134.html Interview with Mr. Perle about U.S. - Soviet Arms Control from the Dean Peter Krogh Foreign Affairs Digital Archives Intercontinental ballistic missiles of the United States Abandoned military rocket and missile projects of the United States