ApolloHoax.net
Apollo Discussions => The Hoax Theory => Topic started by: ka9q on October 24, 2015, 09:37:47 PM
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Looks like Tarkus isn't the only one who has a problem with that DISCOVR sequence showing the moon transiting the earth last July. Our friend Hunchbacked/Inquisitivemind does too:
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The moon doesn't rotate during the video, looks like maybe 5-6 hours in the video, so how much rotation does one expect from a body that complete a rotation in about 720 hrs.? 6/720=3 degrees?
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The original NASA caption says the sequence lasted about 5 hours. During that time the earth rotates 75 degrees but the moon only 2.5 degrees.
Hunchbacked thinks it should have rotated more, but the spacecraft is far enough from both that the effect is negligible.
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He appears to be spatially challenged once again or is that still challenged?
I couldn't find any information on it from the website other than the image of the moon traversing the Earth.
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Not just spatially challenged but mathematically challenged. You can verify everything with a little trigonometry, but evidently he thinks that's another NASA conspiracy.
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Not just spatially challenged but mathematically challenged. You can verify everything with a little trigonometry, but evidently he thinks that's another NASA conspiracy.
Pythagoras was on the NASA payroll?
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Looks like Tarkus isn't the only one who has a problem with that DISCOVR sequence showing the moon transiting the earth last July. Our friend Hunchbacked/Inquisitivemind does too:
There's good reason why the two are having the same problems. I suspected very early that tarkus in fact is hunchbacked. Lots of indicies points to it - in my opinion.
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Did hunchback ever reveal a fondness for the music of ELP?
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If he did, he's mixing up their covers. His icon is the cover of Brain Salad Surgery, not Tarkus.
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Last I heard of him was the 'ohm's law' fail.
Nothing has improved it seems.
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Ohm's law fail? Did I miss that one?
He's also posting to Youtube as "Aerospace Engineer".
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Ohm's law fail? Did I miss that one?
He's also posting to Youtube as "Aerospace Engineer".
I'm going to have to look that one up again... but from what I recall he was calculating the energy requirements of some Apollo equipment and managed to get the formula for Ohm's law wrong.
Here it is :
http://www.apollohoax.net/forum/index.php?topic=460.msg16063#msg16063
Looks like you didn't miss it :)
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Looks like Tarkus isn't the only one who has a problem with that DISCOVR sequence showing the moon transiting the earth last July. Our friend Hunchbacked/Inquisitivemind does too:
This video has been removed by the user.. funny that! :o
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It's truly amazing how he'll keep pounding on the same misconceptions literally for years.
He still claims the LM ascent stage was deliberately imbalanced, even though it's been patiently explained many times that fuel and oxidizer have different densities so asymmetric tanks were needed to balance them.
He still can't understand that core rope memory (the read-only memory in the Apollo Guidance Computer) operates on a fundamentally different principle than the more common read-write core memory with which he was familiar.
Hunchbacked perfectly illustrates why I take the time to debunk hoaxers, even though they (almost) never admit their mistakes. Showing why the LM ascent tanks are asymmetric was trivial, but it took me a little longer to understand exactly how core rope memory worked. Although it's obsolete today, I was impressed with the cleverness of the design and how it overcame the limited technology of the day. I almost always learn something even though he never does.
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This video has been removed by the user.. funny that! :o
Wow! I suppose I should have grabbed a copy while I could.
This isn't totally unprecedented, though. On occasion he has pulled a video in which I've pointed out a major blunder, only for it to go back up later with minor revisions of the form "although all my evidence of fakery was utter nonsense, that's no reason to change my conclusions!"
And sometimes he'll put it back up unmodified. Probably his easiest way to purge a whole bunch of highly critical comments.
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Not just spatially challenged but mathematically challenged. You can verify everything with a little trigonometry, but evidently he thinks that's another NASA conspiracy.
Pythagoras was on the NASA payroll?
But of course, why didn't I think of that ::)
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Despite his persistence with long debunked arguments, Hunchbacked is the most reasonable of CTs. I don't think I have seen him throw insults around. He's actually quite a pleasant individual and quite refreshing compared to the usual offerings.
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This video has been removed by the user.. funny that! :o
Wow! I suppose I should have grabbed a copy while I could.
This isn't totally unprecedented, though. On occasion he has pulled a video in which I've pointed out a major blunder, only for it to go back up later with minor revisions of the form "although all my evidence of fakery was utter nonsense, that's no reason to change my conclusions!"
And sometimes he'll put it back up unmodified. Probably his easiest way to purge a whole bunch of highly critical comments.
Rather like kill the mesenger
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Despite his persistence with long debunked arguments, Hunchbacked is the most reasonable of CTs. I don't think I have seen him throw insults around. He's actually quite a pleasant individual and quite refreshing compared to the usual offerings.
I have to agree with this. He also performs his own (highly flawed) analyses of Apollo technology instead of just parroting the usual claims about no stars, von Braun in Antarctica, etc.
But man, is he stubborn.
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Looks like Tarkus isn't the only one who has a problem with that DISCOVR sequence showing the moon transiting the earth last July. Our friend Hunchbacked/Inquisitivemind does too:
There's good reason why the two are having the same problems. I suspected very early that tarkus in fact is hunchbacked. Lots of indicies points to it - in my opinion.
Did hunbacked keep changing the goalposts, or re-directing to a different subject?
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Despite his persistence with long debunked arguments, Hunchbacked is the most reasonable of CTs. I don't think I have seen him throw insults around. He's actually quite a pleasant individual and quite refreshing compared to the usual offerings.
I have to agree with this. He also performs his own (highly flawed) analyses of Apollo technology instead of just parroting the usual claims about no stars, von Braun in Antarctica, etc.
But man, is he stubborn.
He isn't so polite if you corner him on his deliberate deceptions, i.e. his video claiming footage of Apollo 9 was footage of 16 really in Earth orbit, misrepresenting Apollo footage timestamps, deliberatly speeding video up to make his case, posting 3 totally different versions of his degree as an Aerospace Engineer and claiming it's the same document. He gets nasty when you demand explanations, lol.
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He isn't so polite if you corner him on his deliberate deceptions, i.e. his video claiming footage of Apollo 9 was footage of 16 really in Earth orbit, misrepresenting Apollo footage timestamps, deliberatly speeding video up to make his case, posting 3 totally different versions of his degree as an Aerospace Engineer and claiming it's the same document. He gets nasty when you demand explanations, lol.
I've never seen that side of him. In fact, I've seen many ad hominen attacks on his videos and he has handled his attackers with dignity.
On a scale of 1-10, how would you rate nasty (10 being Jarrah White being full flow)?
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He isn't so polite if you corner him on his deliberate deceptions, i.e. his video claiming footage of Apollo 9 was footage of 16 really in Earth orbit, misrepresenting Apollo footage timestamps, deliberatly speeding video up to make his case, posting 3 totally different versions of his degree as an Aerospace Engineer and claiming it's the same document. He gets nasty when you demand explanations, lol.
I've never seen that side of him. In fact, I've seen many ad hominen attacks on his videos and he has handled his attackers with dignity.
On a scale of 1-10, how would you rate nasty (10 being Jarrah White being full flow)?
Pretty mild, maybe a 6 at his nastiest. He thinks I'm a CIA shill, lolz. He got tired of me, I'm blocked now.
To be fair, I've relentlessly hounded him about that stuff, he honestly has good reason to dislike me. I despise liars, though.
He's got a new youtube sockpuppet , Aerospace Engineer. AE has appeared in some of Hunchie's newer videos to offer his "professional endorsement" to Hunchie's claims.
In a stunning coincidence, AE has uploaded a number of videos that are similair and in some cases IDENTICAL to Hunchbacked's work. Weird, right? He was also using the logo of the school Hunchie claimed to be a graduate of. It's a small, small world, lmao!
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On a scale of 1-10, how would you rate nasty (10 being Jarrah White being full flow)?
Talking of jarrah, he now has a new career interviewing vending machines.. :D :D
(http://i60.tinypic.com/2wmfmtz.jpg)
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On a scale of 1-10, how would you rate nasty (10 being Jarrah White being full flow)?
Talking of jarrah, he now has a new career interviewing vending machines.. :D :D
(http://i60.tinypic.com/2wmfmtz.jpg)
He'll be outwitted..
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He isn't so polite if you corner him on his deliberate deceptions, i.e. his video claiming footage of Apollo 9 was footage of 16 really in Earth orbit, misrepresenting Apollo footage timestamps, deliberatly speeding video up to make his case, posting 3 totally different versions of his degree as an Aerospace Engineer and claiming it's the same document. He gets nasty when you demand explanations, lol.
I've never seen that side of him. In fact, I've seen many ad hominen attacks on his videos and he has handled his attackers with dignity.
On a scale of 1-10, how would you rate nasty (10 being Jarrah White being full flow)?
Isn't Jarrah an 11?
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He'll be outwitted..
Excuse me while I wipe coffee from my laptop screen.
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It's truly amazing how he'll keep pounding on the same misconceptions literally for years.
He still claims the LM ascent stage was deliberately imbalanced, even though it's been patiently explained many times that fuel and oxidizer have different densities so asymmetric tanks were needed to balance them.
He still can't understand that core rope memory (the read-only memory in the Apollo Guidance Computer) operates on a fundamentally different principle than the more common read-write core memory with which he was familiar.
Hunchbacked perfectly illustrates why I take the time to debunk hoaxers, even though they (almost) never admit their mistakes. Showing why the LM ascent tanks are asymmetric was trivial, but it took me a little longer to understand exactly how core rope memory worked. Although it's obsolete today, I was impressed with the cleverness of the design and how it overcame the limited technology of the day. I almost always learn something even though he never does.
Is this the video you are describing? Not being an EE I was lost through all the video and for a non EE it sounds like it makes sense. Of course his proposition is defeated by the fact the AGC worked at least 16 times, not counting A7
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Can some kind person sum up what his problem with core-rope memory is? I'm not up for suffering through his grating voice while waiting for him to get to the point.
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From what I gathered, there are too many wires for sensing and nullifying, then he transistors and amplifiers are all wrong..
That is the best I can do
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Can some kind person sum up what his problem with core-rope memory is? I'm not up for suffering through his grating voice while waiting for him to get to the point.
I've never heard Hunchbacked's voice in any of his videos.
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Can some kind person sum up what his problem with core-rope memory is? I'm not up for suffering through his grating voice while waiting for him to get to the point.
I've never heard Hunchbacked's voice in any of his videos.
All I heard was music along with his flip board diagrams of electronic components and their wire diagrams
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Can some kind person sum up what his problem with core-rope memory is? I'm not up for suffering through his grating voice while waiting for him to get to the point.
It seems to amount to the fact that he can't figure it out, therefore it de facto cannot be true.
Personally, my opinion is he really has not even made the attempt. It really is not difficult.
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My recollection is that he could speak knowledgeably only about relatively recent Intel-type home computer architectures and their associated technologies. Other architectures were simply unknown to him. The notion that there could be other architectures was similarly unknown to him.
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My recollection is that he could speak knowledgeably only about relatively recent Intel-type home computer architectures and their associated technologies. Other architectures were simply unknown to him. The notion that there could be other architectures was similarly unknown to him.
He railed against the MIT personnel with a last comment "they" couldn't speak up with their concerns. Actually I thought the MIT guys did great in problem solving real time issues, along with the original design. abbadon probably said it correctly, I don't understand how it works therefore it can't work
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I admit, I don't pretend to know how that stuff works, but then, I don't pretend to know how that stuff works.
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Can some kind person sum up what his problem with core-rope memory is? I'm not up for suffering through his grating voice while waiting for him to get to the point.
He often invents spurious design "rules" violated by the system in question. He's never able to explain where the rules come from or to derive them from basic physics. His only real justification is that he's never seen things done that way anywhere else, and besides it comes from NASA so it can't possibly work.
Basically, it's a lack of imagination coupled with limited experience and knowledge that makes him think he knows much more than he does. Few things are more dangerous.
The key element of the core rope memory, which I didn't understand when I first looked at it, is magnetic saturation. Unlike read-write core memory, where individual cores retain a magnetized state encoding a 0 or a 1, core rope memory cores are "soft" -- they do not remain magnetized when the external field is removed. They are actually transformer cores whose degree of magnetization follows the strength of the current in the wire(s) running through them. But like all magnetic materials, you can magnetize them only so far; once all the little domains are pointing in the same direction, you can't point any more and core magnetization stops rising. The core saturates, and as long as it remains saturated any further changes in the applied magnetic field no longer induce a voltage in other wires running through it. (A transformer can induce a voltage only when the magnetic field in its core is changing.)
This is the key to the core rope memory. Each address line is provided in inverted and non-inverted form, i.e., there are two wires for each address bit, one carrying current when the address bit is a '1' and the other carrying current when the bit is a '0'. They are all weaved through the cores in such a way that every core has at least one wire carrying current except the one being addressed.
The current in each address line is strong enough to saturate the magnetic core material, inhibiting its ability to couple (act as a transformer) a pulse in a readout query wire to a sense wire. The query wire runs through every core, but the sense wire either goes through a core or around it, depending on whether a '1' or a '0' is encoded at that location. (The data is literally woven into the rope.) The sense wire then goes to an amplifier to detect the pulse, if present.
Again, the key feature is magnetic saturation. The only core able to act as a transformer to couple the readout pulse to the sense wire is the one with no current through any of its address lines, and there's only one of those for any given address. A core with one or more active address lines saturates and is inhibited. In other words, it forms a multi-input NOR (negative OR) gate without using any semiconductors.
To me this was the really clever part. It would have taken thousands of ordinary logic gates to decode the address lines. That's easy today but not in the 1960s when every integrated circuit in the AGC contained just two 3-input NOR gates.
Of course this technique has long been obsolete, and because hunchbacked has never seen it anywhere else he insists it can't work here.
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Some more on core rope memory (since it's such a clever design, even though it's long obsolete).
My previous description encodes only a single bit per core, so why not just use ordinary read-write core memory?
Because core rope isn't limited to a single bit per core. You can have multiple sense lines in a single rope, each going through a core or bypassing it depending on whether you're encoding a '1' or a '0'. With 8 wires you can encode a byte at each core, with 16 you can encode a word, and so on. This is how core rope memory got its high density at the cost of being read-only and difficult to manufacture, but that's what counted in the Apollo project.
This is where hunchbacked objects with a spurious design rule. He claims that with so many wires running through a core the readout pulses would be too weak to detect, but he can't base his objection in actual physics. He would actually be right if the extra wires were short-circuited, but they're not. The non-driven address lines are open circuited, and the sense wires feed a high impedance amplifier that puts a minimal load on them.
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Can some kind person sum up what his problem with core-rope memory is? I'm not up for suffering through his grating voice while waiting for him to get to the point.
I've never heard Hunchbacked's voice in any of his videos.
Ah, sorry -- I was thinking of the Blunder.
The waiting until he gets to the point still stands, tho. My experience of too many conspiracy believer videos is they like the emotional build-up and the long stretches of sombre/scary music over slow Ken-Burnsing of grainy stills...a lot more than they like actually explaining what it is they are so hopped up about.
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Another example (one of many) of Hunchbacked's spurious design rules is in the FM transmitter on the LM, used when transmitting video.
I looked at the design. I recognize it as being in just about every amateur (ham) radio FM transmitter since I became a ham in 1971; it's a classic. It uses a frequency synthesizer to produce the desired S-band frequency from a reference oscillator using a high stability crystal.
A voltage-controlled oscillator (VCO) produces the actual carrier signal. The VCO is also digitally divided down to a relatively low comparison frequency. So is the reference oscillator, by another division factor. The two signals are compared and an error voltage is generated that's proportional to their phase difference. The error signal is filtered and fed back to the VCO, keeping the loop in lock. If the VCO divisor is N and the crystal divisor is M, then the VCO output frequency will be the reference frequency multiplied by N/M. So to tune the radio you change the values of N and/or M. The LM transmitter, however, is tuned to a fixed frequency, 2282.5 MHz.
So how is the FM done? The error signal is filtered by a low pass filter so only "slow" phase errors are passed and tracked out by the loop. High frequency phase noise in the VCO is not corrected, so it's designed to minimize it. You simply add the FM signal to the VCO input downstream of the loop filter, and voila -- the VCO frequency varies with the FM signal around its nominal value. The only drawback is that modulation frequency components must be above the loop frequency cutoff or the loop will track them out as VCO phase noise. "DC restorer" techniques have long been used to do this with analog video waveforms.
Again, this is a classic circuit, widely used for many decades. So what's hunchbacked's problem? He claims the values of N and M are "too big", despite the fact that similar values are used in lots of places and there's no real limitation. Showing him schematics of ham and FM broadcast transmitters that use the same technique didn't seem to phase (!) him; he always managed to find some irrelevant difference from the Apollo transmitter.
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Great descriptions, both went over my limited knowledge of EE, and I believe that is how he may attract many, because his approach while flawed from an experts knowledge id good enough to fool novices like myself. When he talks about shadows or perspective I'm more at ease attempting to debunk him, even though I'm not an expert there either, but his descriptions are nonsense many time.
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Showing him schematics of ham and FM broadcast transmitters that use the same technique didn't seem to phase (!) him;...
I see what you did there. ;)
But seriously, thanks for the explanations. My impression is that Hunchback's tactics very much depend on people accepting him as a qualified aerospace engineer, a graduate from a prestigious French school. As a matter of actual fact, he seems to know very little -- perhaps only that which he's picked up as a hobbyist. But apparently he wants people to think that his eminent academic qualifications mean his explanations should be given unquestioned authority.
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My impression is that Hunchback's tactics very much depend on people accepting him as a qualified aerospace engineer, a graduate from a prestigious French school.
Exactly. He even has a sockpuppet account called "Aerospace Engineer".
As a matter of actual fact, he seems to know very little -- perhaps only that which he's picked up as a hobbyist. But apparently he wants people to think that his eminent academic qualifications mean his explanations should be given unquestioned authority.
I can't tell if he's a hobbyist. He claims to work in the industry, though he's rather vague about exactly what he does. I will say I know quite a few hobbyists who know more than he does, though that's damning with faint praise.
What I can't figure out is how he ever learned anything at all with his know-it-all attitude -- even just enough to be dangerous.
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But seriously, thanks for the explanations. My impression is that Hunchback's tactics very much depend on people accepting him as a qualified aerospace engineer, a graduate from a prestigious French school. As a matter of actual fact, he seems to know very little -- perhaps only that which he's picked up as a hobbyist. But apparently he wants people to think that his eminent academic qualifications mean his explanations should be given unquestioned authority.
That was precisely what I was thinking about those that aren't educated in EE, especially. I question them because of the subject matter (Apollo) happened, but he can persuade the novices or fence "sitters"
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He did mention Clavius in a recent video concerning videos of landing/ascent of the LM. He makes bug ASSUMPTIONS on the ability of the RCS systems to correct the sinusoidal motion of ascent and the orientation of the lander during descent. Both observation were laughable. He doesn't see what he should and see what isn't there. In addition his demonstrations of the movement are grossly exaggerated as opposed to the actual motions.
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I am going at him (again) on his ridiculous assertion that "whistleblower" engineers deliberately mounted the ascent stage propellant tanks asymmetrically to throw the LM off balance. His "proof" of this is the wallowing motion seen on the ascent movies and the statement in the manual that the RCS is needed to correct for off-axis thrust because the ascent engine is not gimbaled.
It was hard to know where to start with that one. Since he doesn't think Apollo is real, it's hard to see how he could think the mission films are evidence of anything. And he seems quite deaf to the fact that no matter how carefully one tried to align the center of gravity with the thrust axis, some imbalance would remain that would require active steering.
When I finally got him to understand that the oxidizer is 1.6 times heavier than the fuel, and that this would require asymmetric tank mounting to balance the stage, he retorted that the asymmetry was more than what was needed. So I found a good blueprint, brought it up in Gimp (similar to Photoshop) and carefully measured the tank positions. The fuel tank was exactly 1.6 times as far from the ascent engine centerline as the oxidizer tank. And now he says he needs to look for himself.
The guy seems to have no sense of real-world engineering at all. Or of the real world, for that matter.
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And he seems quite deaf to the fact that no matter how carefully one tried to align the center of gravity with the thrust axis, some imbalance would remain that would require active steering.
This baffles me no end. In real-world spacecraft engineering, it is a given that mass distribution alone cannot achieve practical passive stability. It's a goal so unrealistic it's not even attempted. Which is to say, we design spacecraft with passive stability in mind. But first-order effects such as the depletion of consumables and second-order effects such as mechanical articulation simply cannot be made perfectly passive. And the control techniques go right down to third-and-greater order effects such as elasticity and resonance in the spacecraft structure. No spacecraft has been designed to achieve stability purely by passive means. At best you need some kind of spin stabilization. Usually you need moment-generating machinery, attitude sensors, and a closed-loop control system. For practical manned space flight including rendezvous, these must be robust and capable systems.
Conversely, control design has never required "perfect" organization and distribution of control-moment generators. There is no perfect placement for RCS jets such that you get no residuals. As such, the mathematics for control system design have been fully generalized since the early 1960s and remain so today. By "fully generalized" I mean based on linear algebra methods such that any combination of attitude errors and rates, and any combination of conjugate control inputs can be reckoned using the same generalized formulas regardless of actual direction or magnitude. This gives rise to reliability engineering in the form of deliberately off-axis and/or non-orthogonal moment generators that tolerate the failures of single units (e.g., reaction wheels or jets). Apollo had a limited ability to do this.
In other words, he's coming at the problem from someone who has some reasonable understanding of the basic dynamics problem, but who quite clearly has no experience whatsoever in the actual design and construction of spacecraft.
The guy seems to have no sense of real-world engineering at all.
Agreed. This is why I'm skeptical of his education claims. He may indeed have some sort of diploma, but it's abundantly clear he's never worked in the industry in any country. And I think he wrongly believes people wouldn't be able to tell that.
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It's not like this stability/control stuff is intuitively obvious without some study or education. IIRC, even Robert Goddard fell for the usual misconceptions when he put his engine nozzles at the top of his rockets hoping that the rest of the mass would automatically hang below it like a pendulum. At least he eventually figured it out, though his obsession with secrecy probably made him take longer than it would have otherwise.
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I am going at him (again) on his ridiculous assertion that "whistleblower" engineers deliberately mounted the ascent stage propellant tanks asymmetrically to throw the LM off balance. His "proof" of this is the wallowing motion seen on the ascent movies and the statement in the manual that the RCS is needed to correct for off-axis thrust because the ascent engine is not gimbaled.
It was hard to know where to start with that one. Since he doesn't think Apollo is real, it's hard to see how he could think the mission films are evidence of anything. And he seems quite deaf to the fact that no matter how carefully one tried to align the center of gravity with the thrust axis, some imbalance would remain that would require active steering.
When I finally got him to understand that the oxidizer is 1.6 times heavier than the fuel, and that this would require asymmetric tank mounting to balance the stage, he retorted that the asymmetry was more than what was needed. So I found a good blueprint, brought it up in Gimp (similar to Photoshop) and carefully measured the tank positions. The fuel tank was exactly 1.6 times as far from the ascent engine centerline as the oxidizer tank. And now he says he needs to look for himself.
The guy seems to have no sense of real-world engineering at all. Or of the real world, for that matter.
Another point in his video the RCS wasn't powerful enough to change orientation or abate those oscillations.
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Another point in his video the wasn't powerful enough to change orientation or abate those oscillations.
The RCS was plenty powerful enough to overcome the residual imbalances and point the ascent engine as it needed to be pointed.
The "wallowing" motion so apparent in the ascent movies is caused by a "dead band" in the control laws. Instead of trying to hold attitude precisely in the desired direction, the computer fires the RCS only when the attitude drifts off nominal by some predetermined amount. Then it fires the RCS long enough to push attitude off-nominal by an equal amount in the opposite direction. The spacecraft swings back and the cycle repeats.
My understanding is that this is done to use RCS propellant more efficiently. They can't be throttled, but they can be fired in very short bursts to give you some desired average thrust over time. But it takes a finite time for the valves to open and for the propellants to flow and ignite, so even though you can command a very short burst it is quite inefficient because most of the propellants come out unburned. By firing longer and less often, more of the propellants are usefully burned. The small errors in attitude have negligible effect on the efficiency of the main ascent engine, and the autopilot can easily steer out any small course deviations that result.
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The LM RCS was sized for the fully-docked, fully-fueled lunar module. The notion that it wouldn't be able to control the relatively empty, relatively light ascent stage only is absurd in the extreme. These are 100-lbf Marquardts on outriggers designed to lengthen the moment arm, rigged so that four jets could operate in concert for each roll, pitch, or yaw moment. They were so oversized for this flight stage they often had to be operated in pulse mode. Ed Mitchell described flying the ascent-only stage as "sporty."
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I wonder if thrusters would still be optimal for an LM designed with today's technology. An alternative would be a set of control-moment gyros for fine attitude control plus one or more thrusters used only to offload them periodically.
You'd still need thrusters for translation, e.g., during docking.
I guess it depends on how long the mission has to be, and particularly if the vehicle were designed to be reusable (e.g., refueled with propellants manufactured from lunar materials). The longer the mission, the more propellant could be saved by a set of gyros and the more attractive they look vs pure thruster control.
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My understanding is that this is done to use RCS propellant more efficiently.
Yes, but in addition there are many reasons in control theory to allow a deadband, especially -- as you note -- when the system has a certain measurable latency.
The small errors in attitude have negligible effect on the efficiency of the main ascent engine, and the autopilot can easily steer out any small course deviations that result.
They average out. If the spacecraft spends half its time on the negative side of the deadband and half its time on the positive side, the instantaneous attitude errors nominally integrate out to zero. It's like changing lanes every 100 meters on the freeway (or dual carriageway). You're constantly driving a few degrees either left or right of the centerline, but on average you're going down the road. The initial ascent was allowed to have quite a wide dispersion, both in up-/downrange errors for LOI, and out-of-plane errors. The idea for the initial ascent was to get to any orbit. Then once a semi-stable orbit had been achieved, phasing maneuvers would bring the ships into compatible orbit. In an extreme emergency, the CSM had some 17 contingency orbits planned to swoop down and rescue the (presumably disabled) LM.
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Reaction wheels are preferred for ships that have a good supply of electrical power.
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They average out. If the spacecraft spends half its time on the negative side of the deadband and half its time on the positive side, the instantaneous attitude errors nominally integrate out to zero. It's like changing lanes every 100 meters on the freeway (or dual carriageway). You're constantly driving a few degrees either left or right of the centerline, but on average you're going down the road. The initial ascent was allowed to have quite a wide dispersion, both in up-/downrange errors for LOI, and out-of-plane errors. The idea for the initial ascent was to get to any orbit. Then once a semi-stable orbit had been achieved, phasing maneuvers would bring the ships into compatible orbit. In an extreme emergency, the CSM had some 17 contingency orbits planned to swoop down and rescue the (presumably disabled) LM.
You can clearly see that in the A17 Ascent and then he complains about the controller not centering the LM in frame, as it drifts to the left I think he assumes that the trajectory must be along the same direction as the camera is facing without rotating. One other aspect, he seems to speed up the videos when is attempting to present his case. ie. A15 landing with the DAC camera.
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I think he assumes that the trajectory must be along the same direction as the camera is facing without rotating.
It was expressly otherwise, and easy to find in the literature. The LM ascended straight up for 10 seconds to avoid local terrain, then began a programmed sequence of increasing pitch-forward maneuvers.
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I think he assumes that the trajectory must be along the same direction as the camera is facing without rotating.
It was expressly otherwise, and easy to find in the literature. The LM ascended straight up for 10 seconds to avoid local terrain, then began a programmed sequence of increasing pitch-forward maneuvers.
My bad, in his information panel this is what he states "it is very clear that the plane of its ascent is perpendicular to the plane of the camera. The trajectory of the lunar module remains in this plane for all the initial the phase. The LM has tilted nearer horizontal as we are looking at the engine. it is right after this that the LM is yawing to the left from the perspective of ther camera I know you don't like going to YT, but if the description isn't understandable here is the linkhttps://www.youtube.com/watch?v=KAmQVZUUosg around 10:21
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I may look at it later, but the fact also remains that the 16mm camera's line of sight was neither aligned along the line of flight nor oriented with respect to any LM axis. This is most apparent in the descent videos (using the same camera mount) where one must tilt one's head to the side to see it as it might have appeared to someone standing at the LMP's station.
That said, there are also out-of-plane corrections done on the ascent. At a certain fuel-optimal point, the LM could be programmed to "yaw" left or right (not strictly a yaw, but the informal equivalent) to change the plane of the orbit. Basically Hunchbacked seems to have little understanding for what the ascent was meant to accomplish. He's comparing the data to what sts60 accurately terms a "cartoon view of the world."
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I may look at it later, but the fact also remains that the 16mm camera's line of sight was neither aligned along the line of flight nor oriented with respect to any LM axis. This is most apparent in the descent videos (using the same camera mount) where one must tilt one's head to the side to see it as it might have appeared to someone standing at the LMP's station.
That said, there are also out-of-plane corrections done on the ascent. At a certain fuel-optimal point, the LM could be programmed to "yaw" left or right (not strictly a yaw, but the informal equivalent) to change the plane of the orbit. Basically Hunchbacked seems to have little understanding for what the ascent was meant to accomplish. He's comparing the data to what sts60 accurately terms a "cartoon view of the world."
chuckle, it definitely yaws before the camera pans away, it may be programmed or corrective you know better than I
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It was expressly otherwise, and easy to find in the literature. The LM ascended straight up for 10 seconds to avoid local terrain, then began a programmed sequence of increasing pitch-forward maneuvers.
It also performed a yaw maneuver during the vertical ascent phase to place the +Z axis in the desired orbital plane.
The main purpose of the vertical rise is to get some upward velocity to clear terrain before heading downrange. Pitchover is a rather abrupt 52 degrees.
If the LM doesn't start level, this isn't corrected until about 2 seconds after liftoff. This is most visible in the Apollo 15 ascent; you can clearly see the ascent stage initially moving to the left as it rises.
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It was expressly otherwise, and easy to find in the literature. The LM ascended straight up for 10 seconds to avoid local terrain, then began a programmed sequence of increasing pitch-forward maneuvers.
It also performed a yaw maneuver during the vertical ascent phase to place the +Z axis in the desired orbital plane.
The main purpose of the vertical rise is to get some upward velocity to clear terrain before heading downrange. Pitchover is a rather abrupt brutal 52 degrees. In His words
If the LM doesn't start level, this isn't corrected until about 2 seconds after liftoff. This is most visible in the Apollo 15 ascent; you can clearly see the ascent stage initially moving to the left as it rises.
Is that description in the mission report?
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Just in case it's causing any confusion, note that the LM axes were named differently than those of the CSM or Saturn V because the crew stood looking perpendicular to the thrust axis rather than along it as in those other two vehicles. In each case the longitudinal axis containing the main thrust vector was the X axis, but while rotation around it in the CSM and Saturn V was "roll", in the LM it was "yaw". What the Saturn/CSM called "yaw" was "roll" in the LM, and pitch was the same in both.
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Is that description in the mission report?
No. "Brutal" is one of hunchbacked's favorite (and most amusing) words. Right up there with "incoherence" as a noun (plural: incoherences).
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Is that description in the mission report?
No. "Brutal" is one of hunchbacked's favorite (and most amusing) words. Right up there with "incoherence" as a noun (plural: incoherences).
Ok so I don't spend an inordinate amount of time searching, where is it?
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You mean in the mission report?
There's also the Apollo Experience Report "Mission Planning for Lunar Module Descent and Ascent" by Floyd V Bennett.
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You mean in the mission report?
There's also the Apollo Experience Report "Mission Planning for Lunar Module Descent and Ascent" by Floyd V Bennett.
That is what I meant, I have the mission reports downloaded, but haven't memorized them. :)