 The X-7's development began in 1946 after a request from the USAF for a Mach 3 unmanned aerial vehicle for test purposes.This unmanned test craft eventually evolved into the Kingfisher, which was later used to test anti-missile systems such as the MIM-3 Nike Ajax, SAM-A-25/MIM-14 Nike Hercules, and IM-99/CIM-10.The Kingfisher was capable of evading the vast majority of weapons systems it was used to test, despite the systems being designed to destroy hypersonic missiles in flight.