Apollo 11

[AdamSmith]

So warning in advance: this is strictly for nerds.

From the Apollo 11 flight journal: http://history.nasa.gov/ap11fj/01launch.htm

PAO: We're through the region of maximum dynamic pressure now.

[As it flies through the air, the rocket must withstand an aerodynamic pressure imparted by its speed through the molecules of the atmosphere. This is like the pressure felt on a hand stuck out of the window of a fast-travelling car. In the rocketry situation, two things are happening to vary this pressure: the vehicle's rising speed makes it higher; the rapidly thinning atmosphere brings it down. The interaction of these two variables leads to a point in the ascent when the aerodynamic pressure, denoted by the letter 'Q', reaches a peak. This is known as Max-Q and is the point when weaknesses in the rocket's structure are most likely to be found out. It occurs at 1 minute and 23 seconds into the flight.]

My only value-add is the boldfacing above.

[RA1]

At first I thought you wrote "rockety" which would have either been uber nerd or "country".

I like parking insertion.

Best regards,

RA1

[RA1]

I sent this to some of my nerd (pilot) friends. One response was, "read every word twice".

Best regards,

RA1

[AdamSmith]

I sent this to some of my nerd (pilot) friends. One response was, "read every word twice".

Best regards,

RA1

They may like this too: When von Braun finally got some authority over the US rocket programs and started building rockets that didn't fall over or blow up on launch, the rest of the US space establishment ( such as it was) started calling his Marshall operation the 'Chicago Bridge & Iron Works' for what everyone but Marshall saw as Von Braun's absurdly conservative over-engineered structures.

They did however function and survive in flight which was not a prominent feature of our rockets to that time.

That conservatism in making the Saturn V structure much stronger with cross-bracing and a central structural member that others argued were unneeded allowed Marshall at the last moment to add that fifth F1 engine in the center that let the whole thing carry out the Apollo mission, a hairily close-run thing from the standpoints of mass, survivability of the LM, etc.

[MsGuy]

Added a fifth engine not originally designed for?

Is that for real or is it a bit of dramatic licence in the re-telling?

[AdamSmith]

Added a fifth engine not originally designed for?

Is that for real or is it a bit of dramatic licence in the re-telling?

Fuck you, cracker. You can look it up.

Jealous of Alabam?

[AdamSmith]

PS I actually did know personally (how else? ) the Rocketdyne people that did it. I mean I knew them much later in their careers .

[MsGuy]

Fuck you, cracker. You can look it up.

After substantial independent research (15/20 minutes), I can now confirm that a 5th engine was indeed added to latter missions of the Saturn V to accommodate the additional mass of the lunar rover. The first couple of missions were apparently made with the 4 engine version.

However Von Braun seems to claim that the 5th engine, together with substantial improvements in the performance of the original engines, left a more than adequate margin of safety. So much for "hairily close run thing".

[RA1]

Every Apollo mission was MORE than hairily close run. If they knew then what we know now, no one would have dared go on such missions. Except for the test pilot credo, " I would rather die, than look bad".

Best regards,

RA1

[MsGuy]

RA1, you make a good point, several in fact. Sitting on top of several thousand tons of LOX and 'rockety' fuel and lighting it afire seems inherently problematic.

Thirty years after, here's an article on one of the Thiocol engineers who did their damnest to stop the launch of the Challenger.

[AdamSmith]

Another bit to show how close-run the thing was, was that the 4 'hold-down arms' that kept the rocket on the ground until the 8.9-second ignition sequence had carried out successfully and all the sensors agreed that all 5 engines had reached full thrust, had to all 4 release within, if I recall, 50 milliseconds of one another, else the difference in release timing would cause the rocket to tip over. Which of course had happened in the pre-Apollo (pre-Von Braun) days.

[AdamSmith]

Hold-Down Arms and Tail Service Masts

Four hold-down arms had to secure the Saturn V firmly on the mobile launcher during assembly, transportation to the launch site, and its stay on the launch pad in all kinds of weather. These devices also had to have the strength to hold down the launch vehicle after ignition, until all engines registered full thrust. Then they automatically and simultaneously released the Apollo-Saturn for liftoff. They did not, of course, have to overcome the full power of all the engines; the great weight of the fueled vehicle counteracted much of the thrust, As an indication of the unusual design requirement, James D. Phillips of KSC Launch Support Equipment Engineering Division won the 1965 steel-casting design contest sponsored by the Steel Founders Society of America for the design of the casting forming the base for the hold-down arms.36 The arms would weigh over 18 metric tons each; the base was to be just under two meters wide, and not quite three meters long. They would stand 3.35 meters high. Nevertheless, in contrast to the huge Saturn vehicle, the hold-down arms seemed much too small to anchor - even momentarily - the huge rocket. On 17 February 1964 the KSC Procurement Division issued a contract to Space Corporation, Dallas, for the manufacture of 16 hold-down arms for the mobile launchers. The cost of the fixed price contract was $676,320, with completion date set for 25 July 1965.37

http://www.hq.nasa.gov/pao/History/SP-4204/ch13-4.html

[RA1]

"Hold down arms and service tail" just seems too obvious to not mention.

Sorry. You know that I have enjoyed this whole sequence of story lines but my "voyeur" mentality overcomes.

You know that isn't true either but we have to write something, don't we?

Best regards,

RA1

[AdamSmith]

This business about how close-run it all was, has another piece (of many) that came out in Apollo 13: how, in contrast to the almost magically lightweighted Lunar Module (its skin famously being the thickness of 3 sheets of kitchen aluminum foil), it turned out that the Command Module was much more robust than even its own designers really knew. From its being powered down for the 2 days or whatever it was that they were on the free-return trajectory and living in the attached LM as the lifeboat, to preserve what little remained in the batteries etc of the Command Module that they would of course need to survive re-entry, then that it actually returned to operation when the crew went back in and went through the 200-step restart procedure. The whole interior was dripping with condensation that should have shorted out the switches, but miraculously they all worked.

[RA1]

Interesting that Morton Thiokol engineers tried to stop the launch. I did not recall this. I do remember that MT was blamed for the gaskets that would not survive a "cold" launch.

LM. Seinfeld has a humorous story about why men like to drive around. What did men do when they went to the moon? Drive around some more. Did they have to go all the way to the moon just to do this? Etc.

I always drip with condensation (sweat) when I try to do a "restart".

Actually it boggles my mind to think about a 200 step restart procedure. From my experience in the aviation world, the end of an emergency procedure is sometimes lengthy and cumbersome but the essentials are usually one-two and you are done, more or less.

Best regards,

RA1

[AdamSmith]

Actually it boggles my mind to think about a 200 step restart procedure. From my experience in the aviation world, the end of an emergency procedure is sometimes lengthy and cumbersome but the essentials are usually one-two and you are done, more or less.

Best regards,

RA1

Of course being in space flight rather than air flight they had (in some of the modes of operation) slightly more leisure to work out solutions than you do.

But they did apparently get quite vexed toward the later hours when they really needed to start getting the CM back into operation and ground control was still not confident of its restart instructions and the flight crew said, rather firmly, Look, something rather than nothing.

[MsGuy]

"Hold down arms and service tail" just seems too obvious to not mention.

Sorry. You know that I have enjoyed this whole sequence of story lines but my "voyeur" mentality overcomes.

You know that isn't true either but we have to write something, don't we?

RA1, I had to puzzle over that one for a day and a half but I finally got it. WOO HOO!

I guess it was a case of me approaching your post with the wrong (serious) mind-set and never being able to back track enough to look at it with fresh eyes. I just went mind blind to the three smilie faces, I guess.

Not unlike the NASA and Thiokol bigwigs when you think about it.

[RA1]

When anyone asks me how to handle emergencies, I always say, first do nothing. Then, after considering the problem, proceed to accomplish the emergency check list. It is amazing how often the first thing done in an emergency is "bad". It is often better to do nothing at first and then do the correct thing. Time to consider is not time wasted (most of the time).

The boys on Appollo 13 had numerous problems but had time to consider how to resolve them and rectify them. And, they did so, brilliantly.

So far I have had numerous problems while flying. Seemingly I have solved most of them satisfactorily or else I would not be writing.

Best regards,

RA1

[AdamSmith]

When anyone asks me how to handle emergencies, I always say, first do nothing. Then, after considering the problem, proceed to accomplish the emergency check list. It is amazing how often the first thing done in an emergency is "bad". It is often better to do nothing at first and then do the correct thing. Time to consider is not time wasted (most of the time).

The boys on Appollo 13 had numerous problems but had time to consider how to resolve them and rectify them. And, they did so, brilliantly.

So far I have had numerous problems while flying. Seemingly I have solved most of them satisfactorily or else I would not be writing.

Best regards,

RA1

I really do think it was Buzz (or Collins?) who said:

The worst time to panic is in an emergency.

[AdamSmith]

A most remarkable achievement of Mission Control was quickly developing procedures for powering up the CM after its long cold sleep. Flight controllers wrote the documents for this innovation in three days, instead of the usual three months. The Command Module was cold and clammy at the start of power up. The walls, ceiling, floor, wire harnesses, and panels were all covered with droplets of water. It was suspected conditions were the same behind the panels. The chances of short circuits caused apprehension, but thanks to the safeguards built into the command module after the disastrous Apollo-1 fire in January 1967, no arcing took place. The droplets furnished one sensation as we decelerated in the atmosphere: it rained inside the CM.

http://science.ksc.nasa.gov/history/apollo/apollo-13/apollo-13.html

[AdamSmith]

This is a rather I think great set of personal recollections:

http://science.ksc.nasa.gov/history/apollo/apollo-11/apollo-11.html

[AdamSmith]

Because once the engines build up and the commit to release and launch is made, there is no way for the rocket to settle safely back down on the pad, should something untoward occur.

One more of those things that Wernher had to explain, over and over.

[AdamSmith]

One small click: thousands of Apollo astronaut photos land on Flickr

https://www.theguardian.com/science/2015/oct/05/one-small-click-thousands-apollo-nasa-astronaut-photos-land-on-flickr

[AdamSmith]

Neat site with detailed history and description of the Saturn V: http://history.nasa.gov/SP-4206/contents.htm