Contract NAS 9-4065, Letter of Direction Concerning Program Development

Massachusetts Institute of Technology Instrumentation Laboratory Cambridge, Massachusetts 02139 Attention: D. G. Hoag, Director, Apollo G&N ProgramAPR 25 196767-FM1-31Project Officer Guidance and Navigation Apollo Spacecraft Program OfficeContract NAS 9-4065, Letter of Direction Concerning Program Development

This letter is to modify your contractual obligation to provide a unique spacecraft computer program for use on the first manned LM mission (formerly designated AS-208). This change in direction is brought about by the slip in the launch schedule for that mission, which makes it probable that suffi- cient time is available to complete the development of the LM lunar landing program (formerly AS-504 LM) in time to support the first manned LM mission. In confirmation of agreement reached between MIT and MSC representatives, it is understood that the development of the LM lunar landing program will pro- ceed in such a way that no more than three months would be required between a decision to stop implementing additional capabilities into this program and the date of its release to Raytheon for rope manufacture. Our intention, of course, is to monitor the development of this program and the scheduled launch date such that if it becomes apparent the lunar landing program will not be available in time, it will still be possible to provide a flight qualified program for this development mission, which has a capability no less than had been planned for AS-208. Proceeding in this manner should assure provision of the highest quality flight program for that mission as well as resulting in a significant reduction in work. It also reduces the risk of having to make modifications in that program which might result if we were to have re- leased it unrealistically early.

It may be necessary to give special consideration to the command and downlink formats to assure compatibility of the spacecraft computer program with their counterpart in the MCC-H to avoid unacceptably expensive effort. Items of this nature will be negotiated on an individual basis.