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After looking at various sources I still don't understand whether the manual mode landing was a necessity because: - of the computer overload due to the comman
by semessier 7y ago
After looking at various sources I still don't understand whether the manual mode landing was a necessity because:
- of the computer overload due to the command module (CM) rendezvous radar being turned on -> which in turn leading to a messy command queue -> commands being dropped from the queue being filled -> commands being sent out-of-sequence -> undefined behavior -> the LM getting of path to the wrong landing region
- of a stone field after an otherwise nominally controlled descent.
In addition it seems unclear whether during manual flight control mode there was still any computer control for attitude, rate of decent etc. active.
- deleted 7y ago[deleted]
- quux 7y agoIn the final phase of landing the AGC was running a program called P66 which was a semi-manual mode. The astronaut had direct control of the attitude of the LM but the throttle was calculated by the AGC to maintain a steady Rate of Descent (ROD). The astronaut controlled the ROD via a switch. All the Apollo landings were done with P66, I think the AGC did have the capability to do a fully automatic landing but none of the crews wanted to try it.
- semessier 7y agoso was it planned then to use P65 (fully automatic) for Apollo 11? It's still not clear what the actual impact of the messed up command queue had - none, a few wrong thruster firings or getting the landing phase trajectory completely wrong?
- semessier 7y agoactually answering my own question in part, it's explained at https://www.hq.nasa.gov/alsj/nasa58040.pdf https://www.hq.nasa.gov/alsj/nasa58040.pdf pp. 21 ff. : P65 was apparently planned and there was a velocity error amongst others leading to a navigation error. What remains open is what material impact the interupt overload on the command queue had.