Apollo 11
#22
Can't abide NAI
Joined: Jun 2007
Posts: 12,078
Likes: 15
From: Douglas Aerospace post production Flight Test & Work Around Engineering bulletin dissembler
GO SEE THIS MOVIE!
It is incredible. They found and sync'd the audio from the experts and specialists, through to mission control, through to the Apollo capsule.
Armstrong's landing on the moon has always been amazing; 16 seconds of fuel remaining. The idea that he was getting warning messages and alarms which were trained as an ABORT scenario up to two weeks before the mission, flew through those on the assurance of experts on the ground, then flew around a football field sized crater, to set down (with a drift rate which is appreciated when you see how he dragged a probe through the Moon dust) to landing is a real feat of piloting skill. For those of you who like formation flying, his ability to whip a spaceship around and stop it on a dime is eye watering. Dude could drive.... .
I've always thought the approach to the moon as particularly interesting. Nobody at the upper levels of Mission Control knew what the warnings were and neither did those on the capsule. Somebody can wiki-search the guy who knew. To hear his voice, sync'd to the events as they played out and how fast it worked it's way up the COC to the Moon ... wow these folks were sharp ... and saved a multi billion dollar mission with the whole World watching.
Which brings me to another point about this movie. The people on the ground are usually left out of any documentary. In this, seeing the people camping out, being ordinary families to witness and incredible event in the history of mankind, gave a lot of relevance to my kids. Yes, this was a BIG DEAL.
With a missed green-slip, tickets and food, the movie cost me something like $3,300. Can't believe I'm writing this but, worth every penny.
It is incredible. They found and sync'd the audio from the experts and specialists, through to mission control, through to the Apollo capsule.
Armstrong's landing on the moon has always been amazing; 16 seconds of fuel remaining. The idea that he was getting warning messages and alarms which were trained as an ABORT scenario up to two weeks before the mission, flew through those on the assurance of experts on the ground, then flew around a football field sized crater, to set down (with a drift rate which is appreciated when you see how he dragged a probe through the Moon dust) to landing is a real feat of piloting skill. For those of you who like formation flying, his ability to whip a spaceship around and stop it on a dime is eye watering. Dude could drive.... .
I've always thought the approach to the moon as particularly interesting. Nobody at the upper levels of Mission Control knew what the warnings were and neither did those on the capsule. Somebody can wiki-search the guy who knew. To hear his voice, sync'd to the events as they played out and how fast it worked it's way up the COC to the Moon ... wow these folks were sharp ... and saved a multi billion dollar mission with the whole World watching.
Which brings me to another point about this movie. The people on the ground are usually left out of any documentary. In this, seeing the people camping out, being ordinary families to witness and incredible event in the history of mankind, gave a lot of relevance to my kids. Yes, this was a BIG DEAL.
With a missed green-slip, tickets and food, the movie cost me something like $3,300. Can't believe I'm writing this but, worth every penny.
#25
Gets Weekends Off
Joined: Sep 2015
Posts: 1,034
Likes: 2
From: I got into this business so I wouldn't have to work.
Millennial (I assume) that has a YouTube vintage space show on all things non shuttle.
https://youtu.be/_Kq67RcfSpw
https://youtu.be/OmCzZ-D8Wdk
https://youtu.be/_Kq67RcfSpw
https://youtu.be/OmCzZ-D8Wdk
I dig the exclamation point tattoo on her left forearm. Yeah, I was looking toward the bottom of the screen. So were you.
#26
#27
China Visa Applicant
Joined: Oct 2006
Posts: 1,963
Likes: 16
From: Midfield downwind
Armstrong and Aldrin have independently said that they never saw the 1201 and 1202 alarms in any of the sim training.
Gene Krantz has stated (in Failure Is Not An Option) that in at least one of the simulator runs (but not with Anderson and Aldrin in the box) a 1201 alarm came up and the sim crew aborted, it turns out unnecessarily. Following this, Krantz directed the GUIDO to come up with rules for these alarms.
A fun little read on the topic:
http://www.collectspace.com/news/new...-apollo11.html
#28
Gets Weekends Off
Joined: Jul 2010
Posts: 12,823
Likes: 168
From: window seat
There are actually two different stories on this, but neither story has Armstrong aborting in the sim over 1201 and 1202 alarms.
Armstrong and Aldrin have independently said that they never saw the 1201 and 1202 alarms in any of the sim training.
Gene Krantz has stated (in Failure Is Not An Option) that in at least one of the simulator runs (but not with Anderson and Aldrin in the box) a 1201 alarm came up and the sim crew aborted, it turns out unnecessarily. Following this, Krantz directed the GUIDO to come up with rules for these alarms.
Armstrong and Aldrin have independently said that they never saw the 1201 and 1202 alarms in any of the sim training.
Gene Krantz has stated (in Failure Is Not An Option) that in at least one of the simulator runs (but not with Anderson and Aldrin in the box) a 1201 alarm came up and the sim crew aborted, it turns out unnecessarily. Following this, Krantz directed the GUIDO to come up with rules for these alarms.
#29
Can't abide NAI
Joined: Jun 2007
Posts: 12,078
Likes: 15
From: Douglas Aerospace post production Flight Test & Work Around Engineering bulletin dissembler
There are actually two different stories on this, but neither story has Armstrong aborting in the sim over 1201 and 1202 alarms.
Armstrong and Aldrin have independently said that they never saw the 1201 and 1202 alarms in any of the sim training.
Gene Krantz has stated (in Failure Is Not An Option) that in at least one of the simulator runs (but not with Anderson and Aldrin in the box) a 1201 alarm came up and the sim crew aborted, it turns out unnecessarily. Following this, Krantz directed the GUIDO to come up with rules for these alarms.
A fun little read on the topic:
Jack Garman, NASA engineer who 'saved' Apollo 11 from alarms, dies at 72 | collectSPACE
Armstrong and Aldrin have independently said that they never saw the 1201 and 1202 alarms in any of the sim training.
Gene Krantz has stated (in Failure Is Not An Option) that in at least one of the simulator runs (but not with Anderson and Aldrin in the box) a 1201 alarm came up and the sim crew aborted, it turns out unnecessarily. Following this, Krantz directed the GUIDO to come up with rules for these alarms.
A fun little read on the topic:
Jack Garman, NASA engineer who 'saved' Apollo 11 from alarms, dies at 72 | collectSPACE
Then, while watching the above videos, ran across this by the same young lady https://youtu.be/kGD0zEbiDPQ
and the best comment ...
"404 ERROR "MOON NOT FOUND"
Last edited by Bucking Bar; 03-07-2019 at 11:23 AM.
#30
Can't abide NAI
Joined: Jun 2007
Posts: 12,078
Likes: 15
From: Douglas Aerospace post production Flight Test & Work Around Engineering bulletin dissembler
"On the last integrated simulation, 11 days before the launch of Apollo 11, a program alarm went off during the descent of the lunar module. Steve Bales was the controller in charge of guidance for the LM, and he had no idea what the alarm meant. He called an abort, with the LM 10,000 feet above the lunar surface. “I had a hard time explaining my actions” after the simulation, Bales says. “Something was going on we didn’t understand, so I thought we should abort.” The program alarms were in part debugging aids, useful to programmers as they developed the programs; they were built in to let a programmer know that the computer was overloaded, unable to finish all the tasks in its execution frame. Mission planners never expected them in real time.
After the aborted simulation, flight director Gene Kranz assembled the controllers, Garman remembers, and told them to develop a response for every program alarm. There were about 40 alarms. “Most were innocuous,” Bales says, “but about 10 were in a class requiring judgment.” For these, Garman says, “the notes we wrote were to the effect that if the alarm doesn’t happen too often and nothing else seems wrong, then the best thing is to just proceed.”
As it happens, Bales was the guidance controller on duty for Apollo 11’s landing on the moon. Exactly 316 seconds into the descent, Buzz Aldrin reported a “1202” program alarm, one of those requiring judgment. Forty seconds later the alarm repeated.
“That was a shock to our system,” says Bales. “We had 10 to 15 seconds to decide what to do. I remember Jack [Garman] talking in my ear, saying ‘It’s not coming too fast, it’s the same type we had before.’ ” Bales called “Go” to the flight director. The alarms recurred three more times before the landing. Because of this distraction (and because they had to fly past the landing site, which was strewn with boulders), the astronauts lost track of where they were, and it took mission control a few hours to pinpoint their location.
It took even longer to determine why the alarms occurred, but the source turned out to be extraneous data from the rendezvous radar. The radar had no role to play in the landing but would be used by the LM after takeoff from the moon for return to the command module. Initial mission procedures called for the radar to be shut off during the landing, but at the last minute it was decided to leave the radar on in case the landing was aborted and it was needed. What mission planners didn’t realize was that while the LM computer was busy carrying out the tasks necessary for landing, it was also processing data from the rendezvous radar.
“The computer was interrupting itself hundreds of times a second, adding and subtracting bits from memory,” says Garman. “Just the act of doing that addition and subtraction stole 15 percent of the computer’s available time.” Carrying out the tasks necessary for landing took about 85 percent of the computer’s available time, so the added work sometimes pushed the computer to the end of the cycle before all tasks were completed, triggering the alarms.
“Had the radar noise problem taken 20 percent of the computer’s time, it’s not clear we could have landed,” says Garman.
“Our software saved the mission,” Hamilton says, “because it was asynchronous—it bumped low-priority tasks. Without it, the mission would have aborted or crashed on the moon.”
Read more at https://www.airspacemag.com/space/practicing-safe-software-180962744/#bfhYbi7MJQtCmTwS.99"
After the aborted simulation, flight director Gene Kranz assembled the controllers, Garman remembers, and told them to develop a response for every program alarm. There were about 40 alarms. “Most were innocuous,” Bales says, “but about 10 were in a class requiring judgment.” For these, Garman says, “the notes we wrote were to the effect that if the alarm doesn’t happen too often and nothing else seems wrong, then the best thing is to just proceed.”
As it happens, Bales was the guidance controller on duty for Apollo 11’s landing on the moon. Exactly 316 seconds into the descent, Buzz Aldrin reported a “1202” program alarm, one of those requiring judgment. Forty seconds later the alarm repeated.
“That was a shock to our system,” says Bales. “We had 10 to 15 seconds to decide what to do. I remember Jack [Garman] talking in my ear, saying ‘It’s not coming too fast, it’s the same type we had before.’ ” Bales called “Go” to the flight director. The alarms recurred three more times before the landing. Because of this distraction (and because they had to fly past the landing site, which was strewn with boulders), the astronauts lost track of where they were, and it took mission control a few hours to pinpoint their location.
It took even longer to determine why the alarms occurred, but the source turned out to be extraneous data from the rendezvous radar. The radar had no role to play in the landing but would be used by the LM after takeoff from the moon for return to the command module. Initial mission procedures called for the radar to be shut off during the landing, but at the last minute it was decided to leave the radar on in case the landing was aborted and it was needed. What mission planners didn’t realize was that while the LM computer was busy carrying out the tasks necessary for landing, it was also processing data from the rendezvous radar.
“The computer was interrupting itself hundreds of times a second, adding and subtracting bits from memory,” says Garman. “Just the act of doing that addition and subtraction stole 15 percent of the computer’s available time.” Carrying out the tasks necessary for landing took about 85 percent of the computer’s available time, so the added work sometimes pushed the computer to the end of the cycle before all tasks were completed, triggering the alarms.
“Had the radar noise problem taken 20 percent of the computer’s time, it’s not clear we could have landed,” says Garman.
“Our software saved the mission,” Hamilton says, “because it was asynchronous—it bumped low-priority tasks. Without it, the mission would have aborted or crashed on the moon.”
Read more at https://www.airspacemag.com/space/practicing-safe-software-180962744/#bfhYbi7MJQtCmTwS.99"
Thread
Thread Starter
Forum
Replies
Last Post





