Tindallgrams

As I understand it, it is currently planned to make a plane change with the CSM in lunar orbit within the last several revolutions prior to LEM ascent. The purpose of this maneuver is to optimize the sharing of maneuver (propulsion) requirements between the CSM and the LEM.

This memorandum is to inform you that there is no computer program currently planned for either the CSM or LEM spacecraft computer to carry out the targeting for this CSM plane change. In other words, in finalizing the onboard computer program requirements for the AS-504 mission, we are assuming that the targeting for this maneuver will be carried out by some source external to the computer, such as pre-mission planning in the form of crew charts or from the MCC in real time.

Of course, the programs needed to execute this maneuver will be available, although not provided specifically for it.

Terms & Abbreviations

504

see AS-504

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.

CSM

Command-Service Module.

LEM

see LM

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.”

MCC

Mission Control Center. Popularly known as “Houston” (as in “Houston, we have a problem”)