Tindallgrams

Topics:

This note is intended to document my understanding of the situation with regard to the spacecraft computer programs for the alternate AS-278 mission. In particular, I would like to record how we are responding to the current programming needs in this area.

Although it was originally stated as a ground rule that alternate missions would be flown using the same programs developed for the primary missions, it appears that that will not be possible in this instance; e.g., there are two contingencies the Apollo Program Office feels it is mandatory to be prepared for. One is an extended schedule slip on the delivery on the first LM spacecraft, and the second is the failure of the AS-206 mission of such a nature that it is not possible to carry out the AS-278 mission as currently planned. The alternate mission (AS-278B) in both of these instances is to rendezvous the AS-207 command module with a LM, man the LM, perform certain spacecraft systems tests and then to initiate a programmed sequence very similar if not identical to the current AS-206 mission after returning the crew to the command module. We are now attempting to determine precisely which additional processors must be added to the AS-206 program in order to permit making such a flight. Of course, the additional requirements depend on precisely how this mission is to be flown, which in turn depends on the guidance system capabilities; e.g., we are in the familiar little cycle. At the least, it appears that the capability must exist to power up the system and align the platform in orbit; however, even these things are not certain.

I have asked Paul Stull and Tom Price to contact the various ASPO and MPAD personnel involved in this mission planning to pin down the possible alternatives for flying this mission, leading to a precise definition of additional program requirements to the 206 program. It is our intention to direct MIT to give the identified processors, which theoretically are already needed in the AS-208 program, highest possible priority such that they may be added to the 206 program at the most opportune time. It appears certain that they will have to be added at some time; e.g., it appears certain a program must be developed to support this type of a flight. There is some question, however, as to whether the 206 program as currently defined is needed since the modified program should be able to fly both the 206 mission and the AS-278B mission. Our basic problem is providing this augmented program in time to support the 206 mission if it is flown; i.e., it depends on the schedule of that flight and the program development required for it.

Accordingly, it is our intention to continue working on the present AS-206 program as currently defined until the latest time at which a decision can be made, probably in the latter part of November or early in December. It is at this time that the final 206 program integration and flight acceptance verification testing will be going on. If, at that time, it is apparent the 206 flight has slipped sufficiently to permit adding the additional processors to support the AS-278B mission, work on the 206 program would be terminated and only this augmented program would be developed for use both on the AS-206 and AS-278B. If the current 206 schedule is maintained, however, we would be forced to complete flight qualified 206 program ropes to be followed later by the augmented AS-206 program for support of the AS-278B mission.

Although some preliminary information has been obtained from MIT regarding over-all schedule impact, it is my intuitive feeling that it is probably not particularly accurate. Therefore, it is my intention to obtain program development plans for the augmented AS-206 program which will include the effect of work on this program on the AS-278/503 and 504 program schedules.

This will be done as soon as the additional program requirements for the AS-278B mission have been defined.

Terms & Abbreviations

278

see AS-207/208

504

see AS-504

AS-206

Originally scheduled as the first unmanned flight of the LM, it was cancelled after the Apollo 1 fire. The AS-206 launch vehicle, a Saturn 1B, was used to launch Skylab 2 on May 25, 1973.

AS-207/208

AS-207/208 (also known as AS-278) was to have been the first test of the LM in Earth orbit. It was also to have be a dual mission with the command and lunar modules launched on separate Saturn 1Bs. The mission was cancelled after the Apollo 1 fire and the Saturn 1Bs were used to launch Skylab 3 (AS-207) on July 28, 1973 and Skylab 4 (AS-208) on November 16, 1978. The LM was first tested by Apollo 5 in January 1968.

AS-208

see AS-207/208

AS-278

see AS-207/208

AS-504

Before the Apollo 1 fire, the mission referred to as AS-504 was originally scheduled for December 1967. AS-504 eventually launched as Apollo 9, March 3 1969.

ASPO

Apollo Spacecraft Program Office.

LM

Lunar Module. Earlier it was known as the Lunar Excursion Module and abbreviated “LEM.” Even after the name change, it continued to be pronounced “lem.”

MIT

Massachussets Institute of Technology. In these memos, MIT is shorthand for the MIT Instrumentation Laboratory, created and led by avionics pioneer Charles Stark Draper. It is now known as the Charles Stark Draper Laboratory and became independent of MIT in 1973.

MPAD

Mission Planning and Analysis Division (part of MSC).