Patrick1000
Banned
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- Jul 22, 2011
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No weasel words, just a few facts and a rat for you!
THE APOLLO 11 LUNAR DESCENT. From the section on page 10; Accuracy of Down Range Estimates, capitals mine;
"It should be noted that the landing-radar update did not correct the PGNS estimate of down-range position but only its knowledge of the velocity and altitude of the LM relative to the lunar surface. The PGNS estimated landing point still was approximately 20 000 feet in error at landing. It should also be noted, however, that an error of this seemingly large magnitude is explained easily. In the nominal Apollo flight plan for lunar-descent preparations, the LM is tracked on one earthside pass of the moon and updated on the next earthside pass. Powered descent then is performed during the next pass. As a result, the last time that the PGNS state estimate normally is updated by the ground is approximately 2 hours (one orbit) before powered descent. In turn, this state estimate is based on tracking data that are also 2 hours old. Consequently, an error in state velocity as small as 0.5 ft/sec propagated over this 4-hour period results in more than 20 000 feet of down-range position error. BECAUSE LANDING POINT ACCURACY WAS A SECONDARY CONSIDERATION ON THE APOLLO 11 MISSION, THIS DOWN RANGE POSITION ERROR WAS UNIMPORTANT. However, for future missions which will have the objective of precision landing in or at a particular area or point, emphasis will be placed on eliminating the sources of error which degrade the PGNS state estimate. The PGNS- versus-PFP differences in down-range velocity (olk) and cross-range velocity (AY) were well within the expected tolerances (fig. 13), confirming excellent operation of both the PFP and PGNS systems."
See the part there abaddon that says, "Because landing-point accuracy was a secondary consideration on the Apollo 11 mission, this down-range position error was unimportant." Which one of these potential rats, I mean authors do you think wrote that. Here are the memorandum's authors and our choices for the rat that penned the above line; Christopher C. Kraft, Jr., Charley B. Parker, Howard G. deVezin, Jr., and Emil R. Schiesser. A distinguished group of rodents indeed.
And poor poor poor H. David Reed, sweat dripping from his face, stomach churning. Here's David again, capitals mine, EXCLAMATION MARK Reed's;
"He explained that we had five different sites. He said “we have MSFN(tracking radars), PNGS (primary LM guidance computer), AGS(backup LM guidance computer), the targeted landing site and, oh yes, the geologist have determined yet another site based upon the crew’s description of the landscape and correlating that with orbiter photos”. No two of these were even close to each other."
Maurice Kennedy; Charles Deiterich III; William Stoval; William Boone III; Glynn S. Lunney; H. David Reed; Jerry C. Bostick (2011-05-13). From The Trench of Mission Control to the Craters of The Moon (ebook Locations 5644-5648).
And Reed again;
"I remember taking my headset off and walking up to the Flight Director, Milt Windler to explain the situation. We only used that kind of face to face communication when we had a serious problem such as this. I detailed the problem as best we knew it and the process that we’d have to follow to get the data we needed, and why we had to start a rev early to finish the calculations and then find the critical lift-off time for lunar launch. I recall the CapCom instructing Buzz Aldrin that we needed him to perform the RR check early but I don’t believe that CapCom explained why, just another check was all. Shaft & trunnion angles were passed up to aid acquisition. Right on time as the CSM cleared the horizon we began seeing data. WE COUNTED THE AGONIZING MINUTES AS THE TELEMETRY CAME FLOWING IN UNTIL THE CSM WAS RECEDING. Now we had the data we needed to run the problem (a rendezvous problem in reverse) and get the correct liftoff time*. And that’s what we used. Later we would find out just where were we on the surface. WE WERE ACTUALLY OVER 25,000 FEET FROM THE NEAREST OF THE OTHER FIVE CHOICES WE HAD! At 5,000-fps orbital velocity of the CSM that could have been up to a ten second error in liftoff. That would have meant we’d need a LOT of RCS (reaction control system fuel) to play catch up or slow down in a rather abnormal (I don’t recall training for this one) rendezvous situation."
Maurice Kennedy; Charles Deiterich III; William Stoval; William Boone III; Glynn S. Lunney; H. David Reed; Jerry C. Bostick (2011-05-13). From The Trench of Mission Control to the Craters of The Moon (ebook Locations 5657-5673).
Sure doesn't look like Reed thought it was UNIMPORTANT, not with those agonizing minutes passing. And lookee lookee lookee here, maybe we have caught a rat! Reed again, capitals mine;
"I was assigned the descent phase for Apollo XII and I WASN'T ABOUT TO GO THROUGH THAT AGAIN. On Apollo-XII we needed to land near the unmanned Surveyor spacecraft that landed in a lunar crater three years previous. So we began looking for a solution to the problem experienced on Apollo XI. We” in this case is pronounced E-M-I-L (Scheisser) when it’s spelled out. He was the soft-spoken genius in MPAD (Mission Planning and Analysis Division) behind the solution."
Maurice Kennedy; Charles Deiterich III; William Stoval; William Boone III; Glynn S. Lunney; H. David Reed; Jerry C. Bostick (2011-05-13). From The Trench of Mission Control to the Craters of The Moon (ebook Locations 5674-5680).
So Reed doesn't want to pass through agonizing minutes again, doesn't want to take his headset off for a serious face to face discussion again, doesn't want to worry about losing his astronauts again, and the same guy that solved this problem, may have been the one to write this line and call it "unimportant", no problem. Again from the trajectory analysis memo, by the quartet of rats already listed above.
"Because landing-point accuracy was a secondary consideration on the Apollo 11 mission, this down-range position error was UNIMPORTANT." Who is the rat that penned that abaddon? Who do you think?
And you thought I was bluffing abaddon, and I haven't even gotten to the heart of it yet. Not even warmed up yet. See you at my next wall of facts. Give my love to RAF, DrPat.
Here is just the teenzeeist weenzeeist taste of things to come abaddon. Check this out; from NASA's memorandum January 1970 entitled, DEVELOPMENT OF GUIDANCE-MONITORING TECHNIQUES AND GUIDANCE-MONITORING EXPERIENCE DURING
THE APOLLO 11 LUNAR DESCENT. From the section on page 10; Accuracy of Down Range Estimates, capitals mine;
"It should be noted that the landing-radar update did not correct the PGNS estimate of down-range position but only its knowledge of the velocity and altitude of the LM relative to the lunar surface. The PGNS estimated landing point still was approximately 20 000 feet in error at landing. It should also be noted, however, that an error of this seemingly large magnitude is explained easily. In the nominal Apollo flight plan for lunar-descent preparations, the LM is tracked on one earthside pass of the moon and updated on the next earthside pass. Powered descent then is performed during the next pass. As a result, the last time that the PGNS state estimate normally is updated by the ground is approximately 2 hours (one orbit) before powered descent. In turn, this state estimate is based on tracking data that are also 2 hours old. Consequently, an error in state velocity as small as 0.5 ft/sec propagated over this 4-hour period results in more than 20 000 feet of down-range position error. BECAUSE LANDING POINT ACCURACY WAS A SECONDARY CONSIDERATION ON THE APOLLO 11 MISSION, THIS DOWN RANGE POSITION ERROR WAS UNIMPORTANT. However, for future missions which will have the objective of precision landing in or at a particular area or point, emphasis will be placed on eliminating the sources of error which degrade the PGNS state estimate. The PGNS- versus-PFP differences in down-range velocity (olk) and cross-range velocity (AY) were well within the expected tolerances (fig. 13), confirming excellent operation of both the PFP and PGNS systems."
See the part there abaddon that says, "Because landing-point accuracy was a secondary consideration on the Apollo 11 mission, this down-range position error was unimportant." Which one of these potential rats, I mean authors do you think wrote that. Here are the memorandum's authors and our choices for the rat that penned the above line; Christopher C. Kraft, Jr., Charley B. Parker, Howard G. deVezin, Jr., and Emil R. Schiesser. A distinguished group of rodents indeed.
And poor poor poor H. David Reed, sweat dripping from his face, stomach churning. Here's David again, capitals mine, EXCLAMATION MARK Reed's;
"He explained that we had five different sites. He said “we have MSFN(tracking radars), PNGS (primary LM guidance computer), AGS(backup LM guidance computer), the targeted landing site and, oh yes, the geologist have determined yet another site based upon the crew’s description of the landscape and correlating that with orbiter photos”. No two of these were even close to each other."
Maurice Kennedy; Charles Deiterich III; William Stoval; William Boone III; Glynn S. Lunney; H. David Reed; Jerry C. Bostick (2011-05-13). From The Trench of Mission Control to the Craters of The Moon (ebook Locations 5644-5648).
And Reed again;
"I remember taking my headset off and walking up to the Flight Director, Milt Windler to explain the situation. We only used that kind of face to face communication when we had a serious problem such as this. I detailed the problem as best we knew it and the process that we’d have to follow to get the data we needed, and why we had to start a rev early to finish the calculations and then find the critical lift-off time for lunar launch. I recall the CapCom instructing Buzz Aldrin that we needed him to perform the RR check early but I don’t believe that CapCom explained why, just another check was all. Shaft & trunnion angles were passed up to aid acquisition. Right on time as the CSM cleared the horizon we began seeing data. WE COUNTED THE AGONIZING MINUTES AS THE TELEMETRY CAME FLOWING IN UNTIL THE CSM WAS RECEDING. Now we had the data we needed to run the problem (a rendezvous problem in reverse) and get the correct liftoff time*. And that’s what we used. Later we would find out just where were we on the surface. WE WERE ACTUALLY OVER 25,000 FEET FROM THE NEAREST OF THE OTHER FIVE CHOICES WE HAD! At 5,000-fps orbital velocity of the CSM that could have been up to a ten second error in liftoff. That would have meant we’d need a LOT of RCS (reaction control system fuel) to play catch up or slow down in a rather abnormal (I don’t recall training for this one) rendezvous situation."
Maurice Kennedy; Charles Deiterich III; William Stoval; William Boone III; Glynn S. Lunney; H. David Reed; Jerry C. Bostick (2011-05-13). From The Trench of Mission Control to the Craters of The Moon (ebook Locations 5657-5673).
Sure doesn't look like Reed thought it was UNIMPORTANT, not with those agonizing minutes passing. And lookee lookee lookee here, maybe we have caught a rat! Reed again, capitals mine;
"I was assigned the descent phase for Apollo XII and I WASN'T ABOUT TO GO THROUGH THAT AGAIN. On Apollo-XII we needed to land near the unmanned Surveyor spacecraft that landed in a lunar crater three years previous. So we began looking for a solution to the problem experienced on Apollo XI. We” in this case is pronounced E-M-I-L (Scheisser) when it’s spelled out. He was the soft-spoken genius in MPAD (Mission Planning and Analysis Division) behind the solution."
Maurice Kennedy; Charles Deiterich III; William Stoval; William Boone III; Glynn S. Lunney; H. David Reed; Jerry C. Bostick (2011-05-13). From The Trench of Mission Control to the Craters of The Moon (ebook Locations 5674-5680).
So Reed doesn't want to pass through agonizing minutes again, doesn't want to take his headset off for a serious face to face discussion again, doesn't want to worry about losing his astronauts again, and the same guy that solved this problem, may have been the one to write this line and call it "unimportant", no problem. Again from the trajectory analysis memo, by the quartet of rats already listed above.
"Because landing-point accuracy was a secondary consideration on the Apollo 11 mission, this down-range position error was UNIMPORTANT." Who is the rat that penned that abaddon? Who do you think?
And you thought I was bluffing abaddon, and I haven't even gotten to the heart of it yet. Not even warmed up yet. See you at my next wall of facts. Give my love to RAF, DrPat.
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