Downthread: Apollo Spacecraft Software Configuration Control Board notes for the March 19 meeting (Apr 01, 1968)
See list belowMAR 7 196868-FM-T-53FM/Deputy ChiefApollo Spacecraft Software Configuration Control Board notes for March 4 meeting
1. Close to half the meeting was devoted to discussion of the Delta V monitor. It was reported that the propulsion people have conferred in writing that the Delta V monitor program should not shut off the SPS engine on the Spacecraft 020 and 101 missions. It was also reported that MIT is still working on the basic Delta V mode design for Colossus, the primary goal being to maintain the PNGCS in a workable state. Tom Price was given the task of organizing the work from MSC's viewpoint and coordinating it with MIT in detail. In the LM programs there are apparently serious implications regarding ullage arising from the 15 second limit for the RCS jets impurging on the DPS. It is still not clear what will be done about that.
2. In response to a previous action item (10.1.4) G&C reported that ullage as commanded by the AGS is DEDA accessible, that is, the crew can change its duration if that is necessary.
3. I withdrew our PCR No. 33 dealing with the lunar surface navigation program in Luminary. This PCR was to obtain radar data on the downlink at a higher frequency than is currently programmed. It became clear that there were a number of unresolved questions dealing with how we want to use both this program and the Ascent program (P-12), which should be resolved before we finalize our PCR description. We were told that we may delay this PCR for another month with no additional program delivery impact and we have some analyses and meetings scheduled which should illuminate the subject considerably.
4. PCR No. 50 deals with changes in Colossus preentry computations and displays (P-61 and P-62). After considerable discussion, MIT was directed to remove the processors in Colossus which provide an automatic maneuver to the command module/service module separation attitude. The other part of the PCR requesting prediction of gimbal angles at 0.05 g's would cost 4 days schedule impact and, since Tom Stafford agreed it was not mandatory, this part of the change was not approved.
5. PCR No. 57 was not discussed at this meeting.
6. PCR No. 63, to delete command module steering of the S-IVB during the TLI maneuver, was finally approved.
7. PCR No. 70, which ass the jerk term to the Descent Abort programs (P-70 and P-71), was not discussed at this meeting since MIT has not completed their detailed evaluation yet. It is supposed to be ready for the next meeting.
8. PCR No. 72,, a LM DAP change to Sundance dealing with attitude rate limits, was disapproved.
9. PCR No. 80 was an MIT initiated change to provide state vector synchronization with no schedule impact for Colossus, Luminary and Sundance. It was approved.
10. PCR No. 81 dealt with a change MIT made in the Auge-Kugel coefficients in Colossus. This was done without MSC concurrence and this approved PCR directed MIT to return to the Sundisk values.
11. PCR's 83 and 85 both dealt with x-axis override in Sundance and Luminary. It was agrees that PCR No. 85 as prepared by MIT was the better, so it was approved; and PCR No. 83 was disapproved.
12. PCR No. 88 provides the capability of changing range variances, whatever they are, in Colossus and Luminary cased on more up-to-date analyses and actual flight experience by putting both of them in erasable. This change was approved for Colossus and Luminary with no schedule impact. A visibility impact on Sundance was requested.
13. PCR Nos. 90 and 91 deal with downlink changes to Sundance requested by FCD, both of which were approved.
14. PCR No. 92, to add a valid date indicator to the Colossus landmark tracking downlink data, was postponed until the next meeting.
15. PCR No. 94 requested a change in the Colossus entry guidance logic such that it will work for reduced L/D vehicles. It was approved.
16. PCR No. 95 which changes the DSKY display polarity for the rendezvous radar trunion angle in Sundance to be consistent with standard pilot sign convention was approved.
17. PCR No. 96, which provides the capability in Sundance of moving the rendezvous radar gyro package out of the view of the AOT was approved with a one day impact.
18. PCR No. 97 removes a program alarm in Sundance associated with the rendezvous radar which was certain to occur during perfectly nominal LM rendezvous operations. It was approved.
19. PCR No. 98 provides a capability of moving the rendezvous radar antenna out of the field of view of the AOT while the rendezvous navigation program is in operation. Discussion of this change was delayed until the next meeting.
20. PCR No. 99 deals with making the DSKY display of shaft and trunion angles of the rendezvous radar in Mode II more meaningful to the crew. It was disapproved for Sundance and will be discussed for Luminary the next time.
21. PCR No. 103 authorizes MIT to do no level 5 testing of the Sundance programs which provide rendezvous maneuver targeting to the CSM, since the P-70 series will not be used on the “D” and “E” missions. This was approved.
22. PCR No. 104 would have deleted the requirement for the P-21 program in Sundance. It provides a display of latitude, longitude and height. When it was understood how the crew intends to use it, the PCR was disapproved.
23. Three changes dealing with the throttling of the DPS in the Luminary program were requested by MPAD and are to be discussed at the next meeting.
24. This memorandum is to give a very brief rundown of what happened at this meeting. It is obvious from the great number of items under discussion that if you are interested in any specific one in detail, you will have to check in person with someone that was there, or await distribution of the formal minutes of the meeting.