Hoax? - Lunar Launches - Too Fast

[JayUtah]

Okay, last post for today, but I'll make it on topic lest I be legitimately accused of posturing.

I'd think the professionals could simply plug this into a 3D simulation, and have it spit out the predicted results -- Fluid Dynamics Rocket engine CAD, package of some sort.

Something like this:
https://info.thermoanalytics.com/rapid-flow-cfd-software

As my spouse would say, "Oh, you sweet summer child."

You missed the industry-standard one (Ansys Fluent), but as you say, you're a rookie. Yes, a huge part of my professional services are providing computational fluid dynamics solutions to paying customers. And yes, you can model rocket nozzles and plumes in Fluent. It's complicated, though. Of the two guys who are more-or-less full-time Fluent wonks at my company, one has a PhD in physics. The notion that you can just "plug in" some values and have it hand you a pat answer is pretty farfetched. You need to really start warming up to the prospect that you don't get to demand that the answer be easy no matter how you want to ask for it.

Let me tell you the biggest reason why you can't just "plug in" some values and have a dialog box pop up with a pat answer. While Fluent and all the other COTS CFD solutions are all reasonably capable and can be run on computers you might have access to, one thing they don't do well at all is integrate fluid effects and mechanical effects. You can get a very accurate picture of what your fluids are doing under progressing conditions of temperature and pressure, and given the appropriate fluid properties and flow regimes. But the solid objects don't respond. You have to do that on your own. Your LM will just sit there and go nowhere.

@JayUTAH - so do you have some professional Fluid Dynamic software to help model this?

Yes and no.

You were perhaps prescient in suggesting the simulation method of solving the problem because that has to do with why I was in Seattle.

Yes, a software system exists to combine the effects of fluid dynamics modeling and the mass and materials properties of objects with which the fluids come into contact. Predictably each iteration of the model employs certain constitutive relationships that can't be obtained by off-the-shelf software.

No, you don't get to use it and neither do I. While my company played a major role in developing it, it does not belong to us and cannot be used for any purpose other than that allowed by the customer who paid for it. That customer has fallen on hard times, and the disposition of this technology arose in the discussion. But the simple answer to your question is that no, you can't just naively type in some numbers to a computer and get an easy answer. If you want to use Fluent, you'll need to do a fair bit of custom programming.

I don't know what principles to apply for the various factors and concerns at play here, to do any meaningful calculations.

Which means you'd be just as in over your head trying to model this in Fluent as you are trying to pursue a crash course in fluid mechanics to solve it the analytical way. That doesn't mean you haven't made some good inroads into the subject, and haven't applied some judicious (and often justifiable) simplifying assumptions in your homework. But there's always more science.

The basics of fluid dynamics are fairly easy...

You may be the only person in human history to say that fluid dynamics are "fairly easy."

This is work for an experienced professional.

Then you should get right on that. You said you started a company to do 3D modeling including the Newtonian physics, and I'm pretty sure you can get an evaluation license for Fluent. Good luck.

[najak]

najak, I'm curious how you became a CT?  What initiated it in your past?  Have you ever considered that you are wrong?  Or has your hard headed conviction that "I'm right no matter what anyone shows me" bars any one from showing proofs that you are wrong, but it does not matter to you, because "you are right".

bknight - thank you for asking..

What opened-my-eyes to govt' propaganda the most was the August 2014 - ISIS journalist video beheading trio.  James Foley was first.  In order to deepen my hate for ISIS, I decided to watch this beheading video - because I had a hard time picturing "melodramatically evil people" - and thought this would help affirm it for me.  Instead, all I saw was a poorly acted video, with some tall skinny masked British guy with a small knife shouting threats against the world, telling us "this is what you get when you mess with us" - and the victim was not James Foley (missing his birthmark, wrong skull structure, wrong voice, poorly acted) -- and then when he went to cut off his head, it fades to black -- no one scream, not one drop of blood..  2 seconds later if fades back in to a "windy scene" (heavy wind sound) of a Still Shot of a beheaded body, that looked like Photoshop.   Despite this heavy wind - not one piece of clothing moved.  Despite ISIS supposedly trying to horrify the world with their barbarism (showing the beheaded body was showing that they wanted to show GORE)... so why not show the actual video with screaming and blood -- if they wanted to show GORE?  Was this PG13?

I was PISSED.  I felt betrayed!.. Flaberghasted.  Not a chance in hell it was real.  Whoever I could convince to watch it -- agreed.  Most wouldn't watch it.  But the News carried on like it was real...  My world was turning upside down here.

Then within the next month, 2 more journalists - an Israeli (Scotlof) and a British aid-worker (David Haines).   So I watched those -- same thing.  Not a drop of blood shed, no screams, very bad acting, and follows up with a "windy scene" showing a still frame with no signs of the actual wind in this film.

Creepy music.   And now I'm getting more pissed by the week.  Why are we being lied to?!!??

1 week later, Sept 10th, 2014 -- Obama announces Air Strikes against ISIS, with expected civilian casualties.  And the USA and British citizens were generally all supportive.  This "evil needed to be stopped".  It needed a response.

Then it clicked.   "Military Tactics 101 -- before attacking an enemy, propagandize them as evil."  This propaganda ensures that your nation's morale goes UP when you attack, rather than DOWN when you attack.  Suddenly there was also much less concern among the citizens of these nation for these "Civilian casualties" in Syria.

Now it made sense.  100%.   I wasn't mad anymore...  this was just our Military "being smart" - it would be dumb to attack without this propaganda.  I could only pray that their motives were "true"...  but surely a mix - probably a heavy mix of money-motives, but using the excuse of "morality based concerns" so that they could sleep at night.

==
My speculation: Were Foley, Haines, and Scotlof killed?  Probably -- but just not on that footage.    Who produced these films?  Probably a USA DoD private contractor, who in return received some profitable contracts.  Yes, this is speculation -- but take your pick.

The Videos were clearly faked.   The other factor at work here is that ISIS surely isn't dumb enough to release footage that taunts the world, as though this is not going to simply have the exact predictable effect that it had -- which is to motivate meaningful retaliation with Jet Bombings.   There's no way they would have been THAT STUPID.  And since they were clearly trying to show GORE... why cut out the video blood/screams? 

My Answer: IN 2014, they didn't have enough talent on this small propaganda squad to do that type of video faking.

And guess what??   This piss poor quality went over without a hitch.

This opened my eyes in 2014.   The videos were soon removed from the internet and could not be found soon after.

===
Two years later - in 2016, one of my well respected travel-the-world engineering classmates, and neighbor - gave me the Apollo scoop one drunken night.  I thought he was full of crap.  Laughed at him.  But the notion stuck - and over the next few years dabbled in it...  went back to him for more of his "reasons for believing" - which had more to do with "this is how politics work" and NOTHING about "faked film evidence" - but more simply "We didn't have the technology to Land and Ascend/Rendezvous" and he thought "didn't even have a rocket capable of taking this 110,000 payload out of Earth's orbit"...  He spent a lot of time in China on business, and as he spoke the language well enough.

I still thought he was crazy... but as I looked into the mechanics of what they did, their 50% accelerated schedule after Apollo 1, cutting more corners rather than slowing down...  The Thomas Baron 500-page report missing after his freak family death, and how we became Space-Exploration buddies with Russia before Apollo 17 launched.     Also Grissom's final words, are meaningful to me, "Jesus Christ, if we can't even talk between 3 buildings, how are we going to get to the moon?"

It simply became evident to me --- IF THEY COULDN'T DO IT - they'd fake it..   because this is what was "best for the nation - a Victory" - and they delivered.  Perception of Victory is the same as real victory -- since "perception" was the only real deliverable to the taxpayers.   

At this point I became 50/50 -- it finally seemed "FEASIBLE" - not fully dismissible.

By 2019 - I was 70/30.   After more dabbling -- this time in the Physics part - of Landing and Ascent. 

Most people have NO CLUE how incredibly unstable it is to balance this LM upon a single centered rocket engine -- and not only that, but to come to upright position from a 90-degree 3000 mph orbit... and hit your target pretty close.   It's like traveling on a pogo-stick while blindfolded (9" windows) on ice while juggling...   6x in a row -- no problem.   And the Ascent was even worse - as most do not realize the extreme difficulty of dealing with free-floating unconstrained rigid body off-axis rotations... (once a small amount of error is introduced from timing/output variance on the RCS thrusters -- you are no longer turning on 90-degree axes).  The RCS thrusters were overpowered, to make fine-tuned adjustments near impossible (because these same thrusters had to work from the 30,000 lbs starting weight down to the final 6,000 lb AM weight before docking ... where the RCS were over powered.  And the motions were very rigid with snap-stops and no off-axis drift, which should be unavoidable.

This dabbling took me to 90/10.

By 2020, I went to go find some "good MLH videos from 2016" and ALL WERE GONE!... I knew what I was looking for - and all were soft-censored hidden.  Instead, All I could find was linked to "top 10 debunked MLH theories"... the bad arguments (none good).   And also, was littered with Flat Earth links -- as though Moon Landing Denial and Flat Earth are equivalent.

As I found myself unable to do any more "looking for good videos" from Google/YouTube - this helped take me to 99%... where I sit now.  This reminds me too much of how the Mainstream truth about the 2014 ISIS Beheadings NEVER QUESTIONED IT -- this was "truth" by all of mainstream, yet I knew differently.

You call me CT -- but so are you, I would imagined... unless you think "Epstein surely killed himself",  "JFK/RFK's assassinations have no chance of being tied to a larger agency",  or even that "Daniel Ellsberg and Snowden must be liars".    MOST people believe in SOME conspiracies.   Not all are created equal.

The Mainstream has effectively brainwashed most into firmly associating ALL Conspiracies to "Flat Earth Stupid".  Now I fear for how easily our Mainstream truth can be manipulated by partnerships with Google/Yahoo/YT/FB...  soft-censorship is HIGHLY EFFECTIVE.   And one of the best ways to discredit MLH is to make sure that "all of the bad/stupid arguments get LOTS OF AIR TIME" - these are the ones you can find easily...  the Good arguments are hidden by Google/YT, unless you know them by-name...

So, this is my calling.  I'm doing it for Grissom, Thomas Baron, and the many unknown whistleblowers who were stopped pre-maturely.  If not for Apollo 1, Baron himself would have been simply FIRED and forgotten... the media treated him like a lying crank, like he was making-it-up...   Until Apollo 1.    Once he compiled this 500-page report, calling on a dozen other witnesses to corroborate - he has a "freak accident late at night with a one-car train at 45 mph"...  after that, his report that he SUBMITTED TO CONGRESS - went missing... never read.   And no more witnesses came forth.

Who knows, maybe I'm wrong.  If so, I'll proudly admit it, and use that as a GOOD EXCUSE TO NEVER WASTE MY TIME WORKING FOR FREE LIKE THIS AGAIN.     I have a calling, and I'm answering that calling.

[najak]

.... much good stuff...

Thank you for the detailed response.

Moving forward, lets Keep things simple where feasible, until there is need for delving into complexity.  And start with indicating your "overall approach", rather than just asking me a question about a specific step, without telling me the "general approach".  It helps a student if they know "the approach" you have in mind.

I wish from the start, you had simply said:
"When exhaust is constrained, the static pressure can build up to cause immense thrust.   To approximate this, you can compare the effective nozzle exit aperture to the inlet aperture from the combustion chamber which is 16.4 sqIn.   With max safe/prolonged Chamber pressure of 130 psia, we can use these aperture ratios to calculate approximate MAX Nozzle pressure, based upon simple gas Flow, Pressure, and Resistance equations for these two apertures in serial, as the exhaust escapes into a vacuum.  So as the rocket rises, and the effective nozzle exit aperture increases, we can estimate the expected Nozzle pressure as a function of altitude/distance.   The expected Thrust Force from this contributor will be: PSI * 750 sqIn.   For example, if the two apertures were the SAME, this method would estimate the Nozzle pressure to be 65 psia (half of the chamber pressure), which would produce IMMENSE THRUST.  (65 psia * 750 == 217kN!)
==
and I'd say, "Wow Thanks!  That makes perfect sense; this sounds important; I'll do it."

And when I raised concern about "Creating New Energy" simply say "Combustion energy is 40 MJ/sec... while the kinetic energy transfer to the AM in the first seconds is only measured in kJ... You should rethink this."

And we'd have saved many hours....

Here are two things I'm asking from you:
1. A50 combustion energy... should be well-known... I just can't find it anywhere.  But Hydrazine is easy to find, 19 MJ/kg.
2. Confirmation of my method for estimating MAX average Nozzle pressure as a function of "lift-off distance" assuming a max sustained-Chamber pressure of 130 psia.

[beedarko]

Who knows, maybe I'm wrong.  If so, I'll proudly admit it

"If we really went to the moon, then anyone who says otherwise is an idiot"
  - Bart Sibrel 

[najak]

"If we really went to the moon, then anyone who says otherwise is an idiot" - Bart Sibrel

I couldn't find this quote from him, only 2nd-hand sources.  So I'll withhold judging Bart for yet another thing, until I know he said it, and the context.  I already hold a general disdain for Bart.

I don't think this way AT ALL.  I know too many geniuses who accept the Moon Landing as Truth, based upon the smart approach of simply defaulting to agreement with "Scientific Consensus".  This SHOULD be reliably the best way to approach most things.  So if this concept has been corrupted, it makes my mission even more important.

I think the average intelligence of the Apollogist may be higher than that of the MLH advocates, as the majority of MLH believers hold this belief based on bad logic/arguments.  Why?  Because for the vast majority, they only get to see what Google shows them, and they can't tell a dumb argument from a good one.  They are merely "lucking in" to being on the side of Truth, despite a lack of aptitude.

If Apollo were 100% genuine - my world just got better, not worse.  But if Santa were real, we could say the same thing.  I'm rooting for Apollo here, but for me, the most compelling evidence indicates MLH.

[ApolloEnthusiast]

6x in a row -- no problem.   

I corrected you on this point once before, and here you are repeating it again. They didn't land six times "in a row". They landed twice in a row, and then 4 times in a row. You don't get to dismiss Apollo 13's existence just because it doesn't fit your narrative.

The "no problem" is also false. There were program alarms on the A11 landing that could have aborted the landing. A12 was struck by lightning on launch. A13 was a well documented, near fatal catastrophe that required a great deal of good fortune to go along with the hard work and ingenuity employed to return the men safely home. A14 had a failure of the landing radar that nearly aborted the landing. A16 nearly missed their landing window, which would have aborted the mission. I don't remember the reason why, but I think it had something to do with the the final orbital adjustment from the initial eccentric orbit to the more circular position.

These are the issues I remember off the top of my head. I'm fairly certain there were issues on both A15 and A17 as well, but I don't remember them well enough to state that affirmatively and I don't have time to look it up at the moment. If it matters to you I will do so later.

The point is, 6x in a row with no issues is a lie. They absolutely failed on the third attempt and most, if not all, successful landings had significant issues that threatened the success of the mission at the minimum. It's a testament to the engineering, planning, training, and overall preparation that they were able to work through the problems and succeed in the 6 of 7 missions, and even in the failure, at least prevented loss of life.

I expect to not see this mischaracterization from you again.

[najak]

I corrected you on this point once before, and here you are repeating it again. They didn't land six times "in a row". They landed twice in a row, and then 4 times in a row. You don't get to dismiss Apollo 13's existence just because it doesn't fit your narrative.
I expect to not see this mischaracterization from you again.

Thanks.   My "6x in a row no issue" is an abbreviation.   Thanks for keeping me honest on it.

I will try to upgrade it to "6x in a row, no significant issues" -- because I'm talking here about the "attempted landing/ascents"... Apollo 13 didn't "attempt" this part.  When I speak of this, I am specifically referring to the Landing/Ascent attempts.   Apollo 13 didn't attempt it.   So I'm not talking about "6 full missions in a row" just "6 successful attempts at landing/ascent".

Apollo 13 made for a good movie, playing on our superstition of the #13... with the Houston take-off time even set to 13:13.   Unlucky by coincidence, or because #13 is really magical like that?   

I say "Significant", because they "hit their marks" (which I think they did within a few miles EVERY TIME) -- which is a big deal given that they started from a speed of almost 1 mile/second horizontally.

They also performed all 6 rendezvous without notable hiccup.   Right?

Did they ever lose comm's?  Tip over?   Miss their mark by more than a few miles?    (all 3 failures were experienced by Odysseus in 2024)

1967 -  They couldn't even talk between 3 local buildings.  1969 - it was all magically better.  Right on Time to make JFK a prophet.

[Zakalwe]

Did they ever lose comm's?  Tip over?   Miss their mark by more than a few miles?    (all 3 failures were experienced by Odysseus in 2024)

Yes, yes and yes.
Not very good at the old research bit, are you?

[ApolloEnthusiast]

Thanks.   My "6x in a row no issue" is an abbreviation.   Thanks for keeping me honest on it.

"Abbreviation" is an odd way to spell "mischaracterization" or "lie".

I will try to upgrade it to "6x in a row, no significant issues"

What qualifies you to determine if the issues were significant, and what criteria are you using for your definition? Near aborts (a dangerous option) on A11, A14, and A16 would seem to be significant to me. Is there something you know that I don't that trivializes those issues?

-- because I'm talking here about the "attempted landing/ascents"... Apollo 13 didn't "attempt" this part.  When I speak of this, I am specifically referring to the Landing/Ascent attempts.   Apollo 13 didn't attempt it.   So I'm not talking about "6 full missions in a row" just "6 successful attempts at landing/ascent".

I can understand and accept that defense of 6 in a row in this context.

I say "Significant", because they "hit their marks" (which I think they did within a few miles EVERY TIME) -- which is a big deal given that they started from a speed of almost 1 mile/second horizontally.

So another example of you dismissing the efforts and competence of a large number of people based on your personal incredulity.

They also performed all 6 rendezvous without notable hiccup.   Right?

I would have to look to be certain, but going with this assumption, why would you expect problems with orbital rendezvous? They'd been doing it successfully since the Gemini program. A9 and A10 also proved the rendezvous techniques in both Earth and Lunar orbit.

1967 -  They couldn't even talk between 3 local buildings.  1969 - it was all magically better.  Right on Time to make JFK a prophet.

Why do you think a communication issue in a machine that had design problems is some kind of barrier to all of the other facets of equipment needed? Why do you find it so hard to imagine that the deaths of 3 of the astronauts didn't motivate people to do better? This isn't the great point you think it is.

Did they ever lose comm's?  Tip over?   Miss their mark by more than a few miles?    (all 3 failures were experienced by Odysseus in 2024)

Yes, yes and yes.
Not very good at the old research bit, are you?

If it's not in a hoax video that he's deemed credible, apparently based on what sounds right to his ear rather than any responsible vetting, then it is certain he is unfamiliar with it.

[Zakalwe]

If it's not in a hoax video that he's deemed credible, apparently based on what sounds right to his ear rather than any responsible vetting, then it is certain he is unfamiliar with it.

Absolutely.
Which is why I'm not bothering to try and educate him. He is not interested in learning in good faith.
I'm happy to let him flounder in his own ignorance. Bringing horses to water and all that.

[JayUtah]

Thank you for the detailed response.

You're welcome. The bottom line is that there's no useful shortcut to answering these questions, or even to arrive at a ballpark estimate. NASA cared only that the ascent motor wouldn't explode, and their primary method of determining that it wouldn't was empirical measurement and testing. That's the easiest way when you have the actual hardware on hand. They didn't care about exceeding rated thrust at launch. They only levied the standard requirement that 90% thrust occur within a certain time.

Moving forward, lets Keep things simple where feasible, until there is need for delving into complexity.  And start with indicating your "overall approach", rather than just asking me a question about a specific step, without telling me the "general approach".  It helps a student if they know "the approach" you have in mind.

When I and others tried that, you mounted a bunch of knee-jerk objections from positions of ignorance that you expected to sidestep the necessary complexity that you didn't understand and decide the problem all on its own. So no. I will not change my approach and I have told you why.

I wish from the start, you had simply said:

I'm not interested in your ability to imagine an alternate universe where you have been a diligent and honest student and where you understood the foundational concepts ab initio.

Here are two things I'm asking from you:
1. A50 combustion energy... should be well-known... I just can't find it anywhere.  But Hydrazine is easy to find, 19 MJ/kg.

Okay, these are reasonable questions. Aerozine-50 is a trade name for a 50-50 by mass mixture of two constituent fuels: hydrazine and unsymmetrical dimethylhydrazine. They don't react with each other; they react individually with the oxidizer. The latter goes by a number of names in the baffling nomenclature of chemistry, so you're not alone in having trouble looking it up. As for how to run the numbers for a mixture, you can just split any relevant mass values down the middle and do the computations for each component by mass separately, then sum the results without any loss of rigor.

Where do we find the heats of combustion? In various engineering manuals, standardized references, and supplier data sheets. In the profession we use a set of printed manuals provided by our suppliers who have done their own calorimetry and other scientific measurements that our in-house labs can't do easily or better.

In the quote, you cite 19 MJ/kg as the heat of combustion in air for hydrazine. That's too imprecise, but if I remember correctly you actually used 19.5 MJ/kg in the computation and that's precise enough. My reference gives 19.41 MJ/kg, but that doesn't mean 19.5 is not acceptable. Mine is just what my supplier measured.

For UDMH, this source https://cameochemicals.noaa.gov/chris/DMH.pdf , which is a fairly standard manufacturer's data sheet (§9.13) gives "Heat of Combustion" as –329.3×10⁵ J/kg, or 32.93 MJ/kg in the form you've been using. Similarly, NIST https://webbook.nist.gov/cgi/cbook.cgi?ID=C57147&Mask=1A8F gives us the standard heat of combustion as -1978.7 ± 3.6 kJ/mol and a molecular weight of 60.0983 for a comparable figure of 32.924 MJ/kg in your preferred units. Note with sympathy that those references each give a different formulation of the "standard" name for the substance. Engineering is hard enough without that nonsense.

However, If those are the values you think you need, then I want you to assure yourself (and/or provide us a rationale) that a standard heat of combustion in air is the right figure for this problem. That presumes that the combustion reaction is with atmospheric O₂ under standard temperature and pressure conditions. You did a very reasonable thing at the start and used hydrazine by itself. But the reaction from which you've obtained heat is

N₂H₄(l) + O₂(g) → N₂(g) + 2H₂O(g) + Δ_cH^⦵₂₉₈

(The obligatory energy term is festooned with plimsolls and such to remind you that it's the value that holds only for combustion in air at a standard pressure and standard [given] temperature; thus I've expressed it properly as enthalpy.)

But that's not the reaction that is used in the ascent motor. The oxidizer is not atmospheric oxygen, but rather nitrogen textroxide, N₂0₄. So instead of using the enthalpy of formation for molecular oxygen under standard conditions (i.e., zero), the computation has to use the enthalpy of formation for N₂0₄.

Here's some values you'll find helpful:

Reactant	Molecular Weight (g mol-1)		ΔfH°gas (kJ mol-1)		ΔfH°liquid (kJ mol-1)
hydrazine N2H4	32.0452		95.35		50.63
UDMH (CH3)2N2H2	60.0983		83.3 ± 3.6		48.3 ± 3.6
(di)nitrogen tetroxide N204	92.0110		9.08		-19.56

And you can use these basic molecular formulas for the combustion reaction:

N₂H₄ + N₂O₄ → 4N₂ + 4H₂O

(CH₃)₂N₂H₂ + N₂O4 → 4H₂O + 2CO₂ + 3N₂

Here are some questions to consider as you grapple with the need to employ general forms.

• Heats of formation are given for standard conditions, hence the °. What adjustments, if any, need to be made to those values for any non-standard conditions that pertain to this problem?
• What chemical phases do the reactions occur in? What phases are the reactants stored in? Does a phase change occur? How should that be accounted for in the balance?
• You can usually ignore the PV term in enthalpy manipulations that occur under standard conditions (or conditions held constant over the reaction). Do those conditions hold true here? Is there an adiabatic change in conditions? (hint: what happens Newtonianly if a magic spell prevents the combustion from occurring at all and the propellants are simply pushed out into space by the upstream pressure of the helium alone?)
• Are the reactions 100% successful? Is there such a thing as a combustion efficiency coefficient?

2. Confirmation of my method for estimating MAX average Nozzle pressure as a function of "lift-off distance" assuming a max sustained-Chamber pressure of 130 psia.

Short answer: no. But I don't have time today to dive into it. We'll do that right and make sure you get credit for the parts you got right.

[najak]

Did they ever lose comm's?  Tip over?   Miss their mark by more than a few miles?    (all 3 failures were experienced by Odysseus in 2024)
Yes, yes and yes.

1. Was not Apollo 11's 4 mile miss the only one who missed by more than a mile?
2. When did they lose comms during landing?  Odysseus lost it for 10 minutes+, and was unable to tell it's own horizontal speed!...  ever wonder why?
3. Tip OVER?  Which ones tipped over?

In comparison to Odysseus 2024 -- Apollo landings were rather uneventful.

[najak]

#1: ....Are the reactions 100% successful? Is there such a thing as a combustion efficiency coefficient?
#2: Short answer: no. But I don't have time today to dive into it. We'll do that right and make sure you get credit for the parts you got right.

#1: Aerozine50 + N2O4 already has a known rating for expected combustion energy per kg.  If you know this answer - just answer it.   It'll take you 5 seconds, and I'll trust you.
#2: How far off do you think is this method I'm using?   What other factors are at work?
#3: With 170 psia fuel feed pressure, and target chamber pressure of 120 psia - what would be a typical "max SAFE pressure at which the engine could operate with our oscillation/instability" (where the pressure reduces the fuel flow, which then cuts pressure, which then increases fuel flow, which then increases pressure --  these type of unwanted (dangerous?) oscillations)

==
I do not see how "starting with a MAX AVERAGE acceptable chamber pressure" cannot be used to at least figure, fairy closely (with 25%) the EXPECTED MAX PRESSURE that might end up occurring inside the nozzle.... as it lifts off and expands the exit aperture.

I get that it won't be exact -- but if something simple can be done to get estimate a value that is "the MAXIMUM, or HIGHER -- or with 25% of it" -- this can tell us a lot real fast.

I believe we can therefore make use of "Average Max Combustion Chamber pressure" in this calculation... and get a decent answer (to at least say that "the contribution can't be MORE than X").

What is the nature of the factors not addressed by this which would make more than a 25% impact on the end result?

[Zakalwe]

Did they ever lose comm's?  Tip over?   Miss their mark by more than a few miles?    (all 3 failures were experienced by Odysseus in 2024)
Yes, yes and yes.

1. Was not Apollo 11's 4 mile miss the only one who missed by more than a mile?
2. When did they lose comms during landing?  Odysseus lost it for 10 minutes+, and was unable to tell it's own horizontal speed!...  ever wonder why?
3. Tip OVER?  Which ones tipped over?

In comparison to Odysseus 2024 -- Apollo landings were rather uneventful.

Go and research it. It's not my responsibility to educate random eejits on the Internet.

[onebigmonkey]

I'm not presuming to comment on rocket science, but it seems apt to share this that was posted on collectSpace:

https://whatsthisthen.com/saturnv/saturn-v-step-by-step-v1.2.pdf

This book:

https://www.cgpublishing.com/Books/Saturn.html

also has lots of material (and an accompanying DVD of short films from the time), and there's also the Spacecraft films box sets on 'The Might Saturns' that can be found on eBay.