Author Topic: A hoax theory...  (Read 10498 times)

Offline smartcooky

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Re: A hoax theory...
« Reply #30 on: October 13, 2015, 02:31:38 PM »
However, round trip delay on voice communications is not the obstacle some think it is. You simply send your "uplink" directly from Houston to your nearby actor-astronauts on earth, and then route their response up to the relay and back. The total round trip time will be roughly as expected, and even if they interrupt each other or the crew microphones occasionally repeat the uplink audio you'll get the same effects as in the actual missions.

But then, wouln't the ham radio eavesdroppers hear CapCom and the quindar tones on the downlink?
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Offline ka9q

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Re: A hoax theory...
« Reply #31 on: October 30, 2015, 01:09:54 AM »
But then, wouln't the ham radio eavesdroppers hear CapCom and the quindar tones on the downlink?
You use a completely separate, low-delay path to transmit Capcom to your fake crew on the ground. At Houston, you combine Capcom with the downlink from the relay satellite parked near the moon, which is repeating "downlink" audio from the crew, and provide their sum to the media as the air/ground channel.

The radio eavesdroppers listening to the downlink would only hear the Capcom, delayed by one lunar round trip time, when there is acoustic coupling between the earphones and microphones -- as happened frequently during the actual missions.

BTW, you would not hear the Quindar tones even under these conditions because they're notch filtered at the uplink transmitter; the world hears them direct from Houston, but the astronauts do not. Their original purpose was just to mute the uplink transmitter (which is on continuously for tracking) when the Capcom is not talking so the astronauts don't have to hear crosstalk on the communication circuits from Houston to the uplink site. Today you'd use digital circuits without any crosstalk, so you wouldn't have this problem.

Anyone pointing an antenna at the moon while Apollo was there and listening to the uplink frequency would likely hear it passively reflected off the moon. So in our hypothetical hoax situation you'd have to pay attention to this detail and have an uplink transmitter even though no spacecraft up there was actually receiving it.

Offline Luke Pemberton

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Re: A hoax theory...
« Reply #32 on: October 30, 2015, 04:05:44 AM »
The more you know about Apollo communications, the more absurd the idea of a hoax relay satellite becomes.

I recall you explaining the absurdity of relay satellites when Phil Webb produced his critique of Jarrah's Exhibit D videos, outlining exactly the same problems that NASA would have setting up such a relay configuration. If I recall, Jarrah also suggested that they could transmit the contents of pre-recorded tapes from  relay satellites to fool the world. Again, another example in hoax world where NASA can create fantastical technology to pull off a hoax, when it would be simpler to actually send men to the Moon.  ???
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Offline Mag40

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« Reply #33 on: October 30, 2015, 05:24:39 AM »
The more you know about Apollo communications, the more absurd the idea of a hoax relay satellite becomes.

Has anyone highlighted the really obvious bit about faking the whole Apollo communications?

  • The volume we are talking about is kind of big. Two weeks of constant dialogue per mission.
  • It's all so very natural and effortless.
  • The voices can be verified.
  • Everything occurs exactly as it should.
  • There are no delay problems.

That thousand hours of natural and perfect audio is really crazy to think it's faked. You'd think :o

Offline ka9q

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Re: A hoax theory...
« Reply #34 on: October 30, 2015, 06:34:13 AM »
Faking the voices, even the conversations about current sports scores and stock market figures, having realistic delays, etc, would be the easy part.

You have to somehow attach those voices to periodic TV broadcasts in which the speakers are obviously in zero or 1/6 gravity for prolonged periods of time.

You have to make the radio signals appear to come from the correct parts of the sky, with the correct Doppler shifts.

You have to actually transmit the uplink signals towards the moon, just in case somebody is listening for the echoes of those signals off the moon.

And you have to cover multiple frequency bands, just in case somebody like Larry Baysinger decides to intercept low power PLSS VHF transmissions instead of the S-band signals intended to travel all the way to earth. As he did, successfully, during Apollo 11.

Offline Zakalwe

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Re: A hoax theory...
« Reply #35 on: October 30, 2015, 06:55:07 AM »
Faking the voices, even the conversations about current sports scores and stock market figures, having realistic delays, etc, would be the easy part.

You have to somehow attach those voices to periodic TV broadcasts in which the speakers are obviously in zero or 1/6 gravity for prolonged periods of time.

You have to make the radio signals appear to come from the correct parts of the sky, with the correct Doppler shifts.

You have to actually transmit the uplink signals towards the moon, just in case somebody is listening for the echoes of those signals off the moon.

And you have to cover multiple frequency bands, just in case somebody like Larry Baysinger decides to intercept low power PLSS VHF transmissions instead of the S-band signals intended to travel all the way to earth. As he did, successfully, during Apollo 11.

In other words, to fake it is probably as hard as actually going there.
« Last Edit: October 30, 2015, 07:02:43 AM by Zakalwe »
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Offline Luke Pemberton

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Re: A hoax theory...
« Reply #36 on: October 30, 2015, 11:59:50 AM »
You have to actually transmit the uplink signals towards the moon, just in case somebody is listening for the echoes of those signals off the moon.

Never thought about that. Jarrah's 'they could have done this and done that' simply does not meet the scrutiny of a real communications engineer. I do like his communication theories [like used in the loosest sense of the word].
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline ka9q

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Re: A hoax theory...
« Reply #37 on: October 30, 2015, 07:17:27 PM »
Jarrah's 'they could have done this and done that' simply does not meet the scrutiny of a real communications engineer.
But naturally I'm just a "NASA shill" so what I say can be ignored.

It's really remarkable how widely the word "shill" is bandied about in conspiracist circles. It might be due to "crank magnetism" (cranks subscribing to a wide range of otherwise unrelated conspiracy theories).

I think it illustrates their inability to differentiate between an opinion, where popularity is relevant, and an assertion of a testable fact, where popularity is (or ought to be) irrelevant.

Offline Luke Pemberton

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Re: A hoax theory...
« Reply #38 on: October 30, 2015, 07:48:19 PM »
But naturally I'm just a "NASA shill" so what I say can be ignored.

Or an alleged engineer, a phrase he uses to describe Jay.

Question: I'm thinking about the rather iconic image of Bernard Lovell holding up the tracking data graph for the Apollo 11 LM, where the bump shows Neil's steely pilot skills as he pilots the LM past the boulder field.

Would there have been measurable Doppler shift from the signals received at Jodrell Bank, and if so, did the scientists measure the shift to confirm the landings as advertised?

I'm fairly sure that you have discussed this before, and pointed out that had the landings not happened as advertised it would have been fairly plain to see from the Doppler (it might have been in a private email when Phil Webb was putting together his Exhibit D critique). My memory is probably wrong on this matter.
« Last Edit: October 30, 2015, 08:12:56 PM by Luke Pemberton »
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline ka9q

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Re: A hoax theory...
« Reply #39 on: October 30, 2015, 08:39:28 PM »
But naturally I'm just a "NASA shill" so what I say can be ignored.

Or an alleged engineer, a phrase he uses to describe Jay.
I recently took my master's diploma to my auto insurance company. They grant discounts to certain professionals, including electrical engineers. It seemed to convince them, so I guess I really am an electrical engineer.
Quote
Would there have been measurable Doppler shift from the signals received at Jodrell Bank, and is so, did the scientists measure the shift to confirm the landings as advertised?
Sure, and very easily.

Apollo communicated with earth with S-band radio signals with a wavelength of about 13 centimeters.  A 13-cm change in distance between transmitter and receiver (the range) therefore causes the phase of the received signal to rotate through a complete cycle of 360 degrees. A velocity along the same line (range-rate) of 13 cm/s will shift the signal by 1 Hz: down if the distance is increasing, up if it's decreasing.

13 cm is pretty short compared to the earth-moon distance, but your ability to detect this relies on having very stable oscillators in both the receiver and the transmitter. This is somewhat difficult to do in a spacecraft, especially one that has to withstand lots of acceleration and vibration, but it's now done fairly often especially on interplanetary probes (e.g., New Horizons).

There's a simpler way when tracking a probe close enough to earth that noise and propagation delay aren't serious problems: with a coherent transponder. To work around the need for an ultra-stable oscillator on the spacecraft, it locks onto the uplink signal from the ground, multiplies its frequency by a specific ratio, and sets its downlink transmitter to that frequency. For Apollo, and every other spacecraft using the same S-band range, this ratio is exactly 240/221. Now you can keep your ultra-stable oscillator on the ground, and even if it changes it will affect the uplink and downlink frequencies by almost the same amount. Note that now you'll see a full 360-degree rotation for each half-wavelength change in range.

This is obviously simplest when the same ground antenna is both the uplink and downlink; this is 2-way coherent tracking. During the Apollo 11 landing, this was done by the Goldstone site in California. Jodrell Bank was simply listening in, making it a 3-way path, so their observation of Apollo's downlink signal would have been affected by all these things:

Frequency errors or drift between the reference oscillators at Goldstone and at Jodrell Bank. (I don't know what they each had, but atomic clocks were already fairly common and I suspect both sites were equipped with them).

The relative motions of the two stations along the earth-moon line caused by the rotation of the earth and moon and the orbital motion of the moon around the earth.

The position and motion of Eagle relative to the lunar surface.

The effect of parallax between the two stations as they viewed Eagle.

Nowadays it wouldn't be hard for a 3rd party site like Jodrell Bank to correct for all these effects and determine Eagle's absolute velocity with respect to the lunar surface, but I suspect they weren't doing this at the time. That explains why they still saw a continuing change in frequency after Eagle landed but one that was abruptly different from what it was during Eagle's descent.


« Last Edit: October 30, 2015, 08:46:07 PM by ka9q »

Offline Count Zero

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Re: A hoax theory...
« Reply #40 on: November 01, 2015, 12:19:22 AM »
I don't know if anyone has posted it in this thread yet, but here is the link to the Jodrell Bank page about tracking the Apollo 11 signal.
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Offline Tedward

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Re: A hoax theory...
« Reply #41 on: November 01, 2015, 01:12:25 AM »
Believe that came up on a TV program on the event in recent years. If memory of the program serves they were tracking the Russian probe that was going to try to upstage the landing (perhaps?) but Jodrell had another dish on 11.

Offline molesworth

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Re: A hoax theory...
« Reply #42 on: November 01, 2015, 04:57:29 AM »
Believe that came up on a TV program on the event in recent years. If memory of the program serves they were tracking the Russian probe that was going to try to upstage the landing (perhaps?) but Jodrell had another dish on 11.
This rang a bell with me, as I was sure I'd read a few things about it.  A quick google turned up a post on some old board about Apollo ;-) http://apollohoax.proboards.com/thread/1988. (I'm not sure if the messages have been copied here, or how to search for them.)

It covers the tracking, and contains a quote from Ian Morison :

Quote
We only needed a 50ft antenna to get a good signal from both the Command Module and the lander (the Eagle).

So maybe a little bigger than the average amateur antenna, but it certainly shows that lots of people all over the world would have had the capability to track the missions.

You can also find the graph of the frequency tracking for the Apollo 11 landing here : http://www.jodrellbank.manchester.ac.uk/multimedia/images/apollo11-eagle.html

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Offline ka9q

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Re: A hoax theory...
« Reply #43 on: November 02, 2015, 04:34:30 AM »
Yes, that's the one I remember. Note the straight but sloping line after the landing. That's not due to the "relative velocity between the telescope and that point on the lunar surface" but to the acceleration along the range vector. A constant range-rate (first time derivative of range) would produce a fixed frequency offset, ie a horizontal line.

Note that this doesn't necessarily mean either end is actually, physically accelerating. It just means that the velocity projected onto the range vector is changing in magnitude as the angle between them changes. You see (or hear) the same thing when a car drives by at constant speed.
« Last Edit: November 02, 2015, 04:39:03 AM by ka9q »

Offline ka9q

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Re: A hoax theory...
« Reply #44 on: November 02, 2015, 08:58:18 AM »
So maybe a little bigger than the average amateur antenna, but it certainly shows that lots of people all over the world would have had the capability to track the missions.
I don't know about "lots", but with an event as big as Apollo 11, enough would that NASA could never get away with a hoax.