 DARPA and Boeing had been working on the "X-45B", a scaled-up X-45A that was seen as the prototype for an operational machine that would reach service in 2008, and would carry a 1,590 kilogram (3,500 pound) load to a combat radius of 1,665 kilometers (900 nautical miles).Two were to be built, but before any metal could be bent for the two X-45B prototypes planned, the Air Force redirected the effort to an even more capable machine, the "X-45C".The goal of the J-UCAS effort was to select a single contractor to provide from 10 to 12 machines for operational evaluation in the 2007