The Thor missile deployment was an emergency response by the US to what was perceived as a missile gap with the Soviet Union. Launch orders for Thor missiles were to be given jointly by UK-US officers from HQ Bomber Command, High Wycombe and USAF 7th Air Division, co-located at the same base. An RAF officer could order a missile to be launched, but a USAF officer had to authenticate arming the warhead. The W49 thermonuclear warhead fitted to a Thor missile had a destructive yield of 1.44 megatons, and weighed 1680 lbs. The missile itself had a CEP of approximately two miles.