 The tests investigated operation of multiple UCAVs in military operations; integration of UCAVs with other military operations; and the feasibility of using reservists to fly the robot aircraft.There has since been X-45B/C versions with greater fuel capacity and hence longer range.The US Navy did not commit to practical UCAV efforts until the summer of 2000, when the service awarded contracts of US$2 million each to Boeing and Northrop Grumman for a 15-month concept-exploration program.