Interface Control Documentation

Interface control documentation, an essential activity during site activation, was another responsibility of KSC's Apollo Program Office. Apollo configuration control dated from February 1963, when the manned spaceflight centers had agreed to consolidate and store interface control documents. During the next several years, Apollo-Saturn subpanels placed hundreds of such documents in a Huntsville repository. Through the interface control documents, Apollo managers made sure that thousands of items, built in many different places, would fit and work together. The documents provided design requirements and criteria for hardware and software interfaces, describing the parameters and constraints under which the interfacing items functioned. The information in the documents varied and might include physical and functional design details and operational and procedural requirements. Where an interface involved two NASA centers, a level A document applied - for example, the interface between a command module (Houston responsibility) and the mobile service structure (KSC responsibility). Level B documents pertained to intra-center interfaces such as the S-IVB-Instrument Unit interface covered by Marshall's Saturn ICD, 13M06307 (October 1965). When changes affected performance, cost, or schedule accomplishment, the centers prepared interface revision notes.15

Although the Panel Review Board (established in August 1963) gave NASA Headquarters limited control over configuration decisions, General Phillips provided the centers with detailed directions in his May 1964 Apollo Configuration Management Manual. The manual, patterned after Air Force procedures, included a requirement for Configuration Control Boards at each center. KSC had difficulty fitting Phillips's management scheme onto a program already under way. In September 1965 however, Petrone announced plans to implement it. Maj. Andrew Reis's Configuration Management Office would "interpret the requirements of [the manual] and define the degree of flexibility necessary to integrate KSC operations consistent with the requirements of Configuration Management."16 Petrone's directive also established a series of Configuration Control Boards, or change boards as they were usually called. Edward Mathews chaired the Saturn IB board; William Clearman, the Saturn V board; and Hugh McCoy, the spacecraft board.17

Apollo-Saturn subpanels continued to prepare interface control documents and notes. When inter-center panel representatives reached technical agreement on an interface requirement, the proposal would go to an appropriate change board. The board would circulate a "request for impact" through KSC to ensure that the proposed document had no adverse impact on any center function. Other details solicited by the change board included the cost of modifications and the "need dates" of operations and maintenance groups. The Configuration Management Office served as a secretariat for the change boards. When a proposal proved acceptable, the board would notify the other centers to implement the document.18

Since unapproved interface control documents left open the possibility of an unsatisfactory interface, program offices made strenuous efforts to coordinate their work. Nevertheless a backlog of "open" documents had developed by 1968 that gave NASA officials much concern. A Boeing investigation in May 1968 found two weaknesses in KSC's program: the documents contained extraneous material that made inter-center coordination difficult, and the complicated processing wasted time. KSC's program office overhauled its procedures during the next six months and closed out all control documents before the first manned launch of an Apollo-Saturn in October 1968.19