Cortright responded to Hilburn quickly with a lengthy description of the NASA-Boeing negotiations as they had developed through March. The Lunar Orbiter Program, he stressed, was attempting to make the maximum use of flight-proven hardware. This meant that Boeing would serve as the prime systems integrator because it alone retained the  responsibility for the Lunar Orbiter spacecraft structure and attitude control system. Boeing and NASA would spend more than 50% of the contract funds on hardware which Eastman Kodak and RCA would supply.
Contrary to Hilburn's major worry, the Boeing Company had a well-developed electronics capability gained through its experience as contractor for the Bomarc, Dynasoar, and Minuteman systems, and despite this NASA negotiators had encouraged Boeing to look for companies with greater competency in guidance systems: Northrop, Philco, General Electric, and Bendix, for example. Moreover, during the final phase of the Ranger Program when a fifth block of spacecraft had been under consideration, Northrop had been prime contractor. When the Block V Rangers were canceled in December, 1963, Northrop had been assigned to conduct a technology transfer study. This study had proved very useful to NASA and Boeing.13
Cortright stressed that the Lunar Orbiter Program Office and the Boeing Company were basing contract talks on the axiom that they use as much off-the-shelf hardware  as possible.14 He stressed that because the attitude control system of the Lunar Orbiter spacecraft would have to fulfill many more demands than that of a Ranger or a Mariner deep space probe, and because the system was so interrelated to all other spacecraft systems, the Office of Space Science and Applications had decided that the prime contractor, Boeing, should take the full responsibility for the attitude control system and its integration with all other systems. However, NASA and Boeing had reached agreement that the latter would use at least the following items of hardware in building the attitude control system:
The brain of the spacecraft would be the Flight Programmer, an electronic wizard approximately the size of a shoe box, and its performance could determine the success or failure of any mission to the Moon. Because of the crucial role of the Flight Programmer, its configuration significantly influenced the design of the rest of the Lunar Orbiter's systems. (See Chapter VI for a description of the Flight Programmer.) The completion of the Programmer would have to await the integration of the spacecraft's other components and subsystems so that it could be placed in the spacecraft as the nerve center linking all of the parts together in an electronic organism.
Langley and the Office of Space Science and Applications believed that Boeing had to retain the complete responsibility for the Programmer, the attitude control system, and their integration. Boeing also would conduct any necessary analyses., engineering.. and computer studies of this system in order to have the working flexibility to cope with unforeseen problems and unexpected changes.16
This arrangement in no way meant that Boeing would  undertake the completely new design and fabrication of a unique attitude control system. On the contrary, the record demonstrated convincingly that the contractor was attempting to use as many off-the-shelf and flight-proven items of hardware as possible and that it was utilizing experience gained in earlier NASA programs.