Author Topic: Apollo 11 Lunar Lander Pre-Launch  (Read 203190 times)

Offline Zakalwe

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #195 on: December 18, 2018, 04:42:04 AM »
and you have failed to produce the MIT paper you claimed as evidence that the RCS was easily knocked into an unstable positive feedback loop. Where is it?


Indeed. Where is it?

Assuming (s)he produces it then we can see if it's relevant, says what (s)he thinks that it says and has been reviewed. Just because its an "MIT paper" doesn't imply that it's correct.
As it stands, it's nothing more than a paper-thin attempt at an appeal to authority. So, jr Knowing, where is the paper?
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Offline Jason Thompson

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #196 on: December 18, 2018, 06:09:55 AM »
and you have failed to produce the MIT paper you claimed as evidence that the RCS was easily knocked into an unstable positive feedback loop. Where is it?


Indeed. Where is it?

Assuming (s)he produces it then we can see if it's relevant, says what (s)he thinks that it says and has been reviewed. Just because its an "MIT paper" doesn't imply that it's correct.

It also doesn't imply that it has been properly understood. There may well be a scholarly paper that discusses the possibility of instability in an RCS system, because arising instability is a potential problem in absolutely any control system from a spacecraft RCS to riding a bike. Pointing out that the problem exists and saying it is an insurmountable problem requiring absolutely perfect conditions, and that any deviation must inevitably lead to a disastrous loss of control, are two different things, however.

I await jr producing the paper so we can see what it actually says.
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Offline Mag40

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Offline bknight

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #198 on: December 18, 2018, 07:44:58 AM »
and you have failed to produce the MIT paper you claimed as evidence that the RCS was easily knocked into an unstable positive feedback loop. Where is it?


Indeed. Where is it?

Assuming (s)he produces it then we can see if it's relevant, says what (s)he thinks that it says and has been reviewed. Just because its an "MIT paper" doesn't imply that it's correct.

It also doesn't imply that it has been properly understood. There may well be a scholarly paper that discusses the possibility of instability in an RCS system, because arising instability is a potential problem in absolutely any control system from a spacecraft RCS to riding a bike. Pointing out that the problem exists and saying it is an insurmountable problem requiring absolutely perfect conditions, and that any deviation must inevitably lead to a disastrous loss of control, are two different things, however.

I await jr producing the paper so we can see what it actually says.

Indeed, take for instance the combustion instability of the F-1 engines.  It was noted and the engineers worked long and tedious hours without the benefit of supercomputers modeling to solve the problem and allow them to work.
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Offline Peter B

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #199 on: December 18, 2018, 07:57:06 AM »
Wheels in different directions (All four LRV wheels were independently steered)

All four independently powered, yes.  Steering was pairwise, front and back.  Front and rear pairs could be independently enabled, though.

Can I just check something about the steering, though.

My understanding is that on ordinary cars here on Earth, when you turn the steering wheel, the front wheels turn by a slightly different amount given that the wheel on the inside of the turn has a slightly smaller radius to traverse. Is that so?

Was this the case with the lunar rover? After all, I understand the rover had a tighter turning circle than cars here on Earth, so the effect described above would be more pronounced.

Given that the rover in the photo JR Knowing linked seems to have stopped while turning, that would suggest to me that the rear wheels would logically not be parallel, but out of parallel by perhaps 10-20 degrees.
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Offline ka9q

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #200 on: December 18, 2018, 08:14:59 AM »
Indeed, take for instance the combustion instability of the F-1 engines.  It was noted and the engineers worked long and tedious hours without the benefit of supercomputers modeling to solve the problem and allow them to work.
Don't military ordnance people like to say that there's no problem that can't be solved with a suitable application of high explosives?

Offline bknight

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #201 on: December 18, 2018, 09:00:37 AM »
Indeed, take for instance the combustion instability of the F-1 engines.  It was noted and the engineers worked long and tedious hours without the benefit of supercomputers modeling to solve the problem and allow them to work.
Don't military ordnance people like to say that there's no problem that can't be solved with a suitable application of high explosives?

The only ordnance I was involved was in the FA and yes if you wanted to destroy something HE rounds were great. :)
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Offline Abaddon

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #202 on: December 18, 2018, 09:04:39 AM »
Wheels in different directions (All four LRV wheels were independently steered)

All four independently powered, yes.  Steering was pairwise, front and back.  Front and rear pairs could be independently enabled, though.

Can I just check something about the steering, though.

My understanding is that on ordinary cars here on Earth, when you turn the steering wheel, the front wheels turn by a slightly different amount given that the wheel on the inside of the turn has a slightly smaller radius to traverse. Is that so?

Was this the case with the lunar rover? After all, I understand the rover had a tighter turning circle than cars here on Earth, so the effect described above would be more pronounced.

Given that the rover in the photo JR Knowing linked seems to have stopped while turning, that would suggest to me that the rear wheels would logically not be parallel, but out of parallel by perhaps 10-20 degrees.

Yes.

Ackerman steering geometry

https://en.wikipedia.org/wiki/Ackermann_steering_geometry

Offline Peter B

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #203 on: December 18, 2018, 09:15:38 AM »
Hi Everyone,

A couple of things. And again I am not sure why everyone response's revolve around side topics that are somewhat meaningless.

If you do not want people's responses to include 'side topics' then stop bringing them up. The responses have only been to things you bring to the discussion, so quit whining about it and own your agency in this discussion instead of dancing around it and casting it off when it becomes inconvenient to you to admit you were wrong.

...

Quote
In any event, I don't really care about this.

Then why even mention it? If you want this discussion to avoid 'meaningless side topics' then don't bring them up in the first place. You're still doing it now.

...

Quote
I am just literally looking for answers.

You're getting them. The next step is for you to acknowledge them, not brush them under the carpet as 'no biggie'.

Once again, you are playing a big part in how this discussion progresses. You've had this explained to you several times now, so if you want to have a debate then have a debate. Engage with the answers, don't dismiss them and say 'well it still doesn't look right to me'. How much would be required for you to admit your ideas about how it 'should' look are wrong, and that this might just mean your entire conclusion is also wrong?

It's an intriguing aspect of Apollo Hoax beliefs which keeps cropping up - regardless of whether we answer questions or ignore them, the Hoax Believers find both courses of action puzzling/disturbing/suspicious. If we fail to answer then we have something to hide; if we answer them then there must be something we want to deflect attention from.

Come on JR Knowing - you've read enough of these threads to see that the denizens of this place are quite willing to openly admit they've been shown to be wrong. Do you think you can do that with regard to the questions you've airily waved in our direction?
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Offline JayUtah

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #204 on: December 18, 2018, 09:16:30 AM »
Just because its an "MIT paper" doesn't imply that it's correct.

Since it was MIT who designed the system, I'd stipulate that the paper -- taken as a whole -- is almost certainly correct.  The Charles Stark Draper lab produced a host of written materials discussing the theory and practice of three-axis control as it related to Apollo spacecraft.  And why shouldn't they?  They're academics, the premier academic institution for this sort of thing.

But that won't stop someone from quote-mining any of their work and handwaving up a case for overall instability based on it.  Again, the standard work here is Sidi's Spacecraft Dynamics and Control, which presents the generalized MIT solution in a more didactically friendly format and covers the rest of the topic thoroughly.
« Last Edit: December 18, 2018, 09:59:13 AM by JayUtah »
"Facts are stubborn things." --John Adams

Offline JayUtah

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #205 on: December 18, 2018, 09:27:00 AM »
As already mentioned by others, it's because you keep introducing [side topics] (and do so again below).

My impression is that by "side topics" he means the references to the rhetorical games he thinks he's getting away with.  I gather he wants the debate to be solely about fenders and antennas and plume deflectors, not how he's failing at manipulating the discussion so as to avoid intellectual honesty or responsibility.  It's like someone playing football (the kind actually played with the feet) and complaining that the ref keeps stopping the game to penalize him for using his hands.  Let's just play "football" already!  So yeah, he's trying to play more games by shaming people away from noticing all the games he's playing.
"Facts are stubborn things." --John Adams

Offline JayUtah

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #206 on: December 18, 2018, 09:44:51 AM »
Yes, the LRV used Ackerman-geometry steering.  Outer wheel can deflect 22 degrees off-axis; inner wheel can deflect 50 degrees off-axis.
« Last Edit: December 18, 2018, 09:49:36 AM by JayUtah »
"Facts are stubborn things." --John Adams

Offline Von_Smith

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #207 on: December 18, 2018, 10:07:50 AM »
Hi Von_Smith,

At the risk of adding one more meaningless post. My first post tonight was in response to a few days of posts aimed at me talking about the government and the foreshortened Rover. I made it clear in that post that we are off topic and need to get back on track. And the posts since then (including yours)? All off topic. I get it. If you want me to admit I am guilty of introducing side topics. I guess I am. And if Jay wants me to admit that people have given plausible explanations for some of the questions I have asked. Sure.

Can we just move on? Lets focus on the topics and I will do my best to keep on topic.

Very well.  We can start by going back to a question I asked you about the original topic that I have yet to see you answer:

You said in your original post that the deflectors were "problematic" and claimed that an MIT paper had suggested that they would create significant instabilities in anything other than perfect conditions.  Now you're suggesting that the deflectors would have been considered necessary by any competent observers, and so had to be there in order to fool them.  So which is it?  Are the deflectors what one would expect on a legit mission or not?  Are they features that "don't look right" or ones that look exactly the way they need to in order to fool the experts among the audience?

Offline Northern Lurker

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #208 on: December 18, 2018, 10:45:48 AM »

You also mention that questioning the moon landings is akin to "smearing one of humanity's great engineering achievement". I get that. That is why I try to tread lightly. I know this means a lot to many people.

I want to clarify that moon landings, Apollo program or space flight in general are not sacrosanct topics which cannot be criticized. We can debate whether they are good use of tax payer's money, are they the best way to make science or what Apollo with today's technology would be.

Smearing which I loathe is efforts of some unnamed entities to cherry pick parts that look weird, parts that look wrong for layman's common sense and (un)healthy dose of bald lies and omission to create hoax narrative and then monetize that by patreon supporters, website ads or selling magazines, books, DVDs and other paraphernalia.

Second form which I loath almost as much are those who want to be something special and accomplish that by pushing others down. Apollo was scientific, management, engineering, manufacturing and Cold War propaganda success story which was founded on talented individuals who accepted mortal risks, sacrificed their family lives and some even their lives.

On the other hand people who have genuine questions about Apollo or space flight in genereal are heartily welcomed. Answering their questions gives opportunity to talk about the thing we are interested about. And it gives satisfaction when someone clears they misconceptions, thank you and either stay to learn more or walk away little bit wiser.

Unfortunately you don't act like the third type. You seem to have preconceived idea that Apollo was faked and when your concerns get addressed, you don't thank for new information and rethink your attitude. Instead you just ignore it and raise another concern. And another. And finally complain that the discussion won't stay in one topic.

Lurky

Offline bknight

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Re: Apollo 11 Lunar Lander Pre-Launch
« Reply #209 on: December 18, 2018, 10:48:33 AM »
jr:

I don't understand (something about images) therefore they must be fake.  It doesn't look right to me (something about images) therefore it must be faked.  I can't believe that works(don't understand how it works) therefore it must be faked.  The images are similar therefore they are faked.


Anymore propositions?
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan