Bochum Bunkum

Short and sweet for his one, but it does allow the addressing of many claims made about transmissions from the moon and how they were intercepted.

In this case, our faithful doggy is refuting claims made about a recording made by Bochum observatory of Apollo 11 descending to the lunar surface. That recording can be found here.

I haven’t seen the original claim to which he’s responding, but I’ve seen his response, as well as an earlier one relating to tracking.

The claim he’s disputing is that NASA sent tapes of Apollo recordings to be digitised, and he’s also stating that Bochum had no formal involvement in Apollo 11.

He’s absolutely correct: Bochum observatory did not form any part of any of NASA’s tracking or communications network - see the diagrams below from the Apollo 11 press kit, and from Honeysuckle Creek.

Germany is conspicuous by its absence, so there’s no reason whatsoever that NASA would ask them for anything, or to do anything.

Then it all seems to get a bit confused for stray as he copies and pastes his pet AI’s responses. He seems happy that Bochum was able to receive S-Band transmissions from the moon, but somehow this doesn’t mean they were on the moon:

Bochum could detect the S-band carrier and measure its Doppler shift.

Bochum could not extract or hear any astronaut voice or telemetry.

Bochum’s 20-meter dish detected and tracked the S-band carrier signal from Apollo 11 at lunar distance. The observatory did not have the capability to demodulate the signal, so it did not hear or record astronaut voices, telemetry, or TV. Its recordings consisted solely of the carrier signal itself.

What about the voice recordings made by Bochum then?

Now, I’m not sufficient an expert in Unified S-Band to know anything about what’s required to listen in to what it says, or what data it may contain. A point here is that neither is Straydog. Rather than educate himself on the topic, or stfu (which are the only two responses available), he just repeats what AI says.

While data, telemetry, TV and voice transmissions were all packed into USB transmissions, the lunar module and command module communicated with each other with VHF. The VHF signal wasn’t powerful, but there is absolutely nothing in the way of those transmissions other than a few miles of atmosphere. Radio hams send transmissions to the moon and back for fun as ‘moonbounce’ (or ‘EME’, Earth-Moon-Earth), including in the S-Band frequency range and with Doppler capability. All the S-band information is detailed here. The Apollo astronaut’s also sent signals to the LM while on the surface, and those signals could also be intercepted on Earth with the right equipment.

This diagram, from a 1969 ‘Electronics World’ shows the various communications links.

It’s those leaky transmissions that the receivers on Earth, be they amateur radio hams like Larry Baysinger, or professional astronomers like Bochum observatory, are picking up.

Baysinger’s recording was from the astronaut suit transmissions, but Bochum’s features the actual landing process itself, so has to come from the LM during flight. How come?

This site has the explanation.

The S-band downlink had two modes: PM and wide band FM. In the PM mode, used during flight, voice was on a narrow band FM sub carrier that phase modulated the main carrier along with other information. This could be received by relatively small dishes.

In simplest terms, the larger the amount of information being sent, the bigger the dish you need to intercept and decode the S-Band signal. While sending back TV, you need a big dish, and Bochum’s wasn’t big enough for that. What it could intercept was the much narrower voice only transmission sent during landing. It’s not clear whether Bochum were receiving S-Band or VHF transmission, but either way is possible with the equipment they had.

So the reality is that while you need a big dish to intercept and decode S-Band that’s returning a massive amount of data, you need a much smaller set up to receive much less data. You need an even smaller set up to intercept transmissions that aren’t in S-Band.

Stray makes many more errors in his interpretation of reality. He says this:

Most of the "Bochum tapes" people hear today were actually recordings of the Voice Call (NASA's public broadcast) or signals relayed to them.

When the reality is, like Baysinger’s recordings, all you hear is the Apollo 11 conversation, not the corresponding voice from Houston. He’s also critical of a claim that Bochum recorded lunar rover TV footage from Apollo 16. There is, as far as I am aware, no recording available of that broadcast, but it is reported in many places - this one, from October 1972, being the most detailed, giving a lengthy explanation (in German) of who was involved, what equipment was used, and even shows a still from Bochum’s recording, seen below with the same view in colour.

So despite his protestations that it was impossible, there we are. He doesn’t really say why it’s impossible, but trust me bro, AI says so. Stray does emphasise that they couldn’t have decoded colour TV, but there’s no claim (as far as I can tell) that colour was decoded, just a TV signal.

His notions about dish size are worth examining. He’s confident that Bochum’s 20m dish couldn’t decode TV, but a 3m wide portable S-Band antenna was used on Apollo 12 and 14 to transmit TV and other data from the surface, and an even smaller one from the LM itself on Apollo 11.  To be fair, receiving a TV signal and sending and decoding it are two different things. Once the signal leaves the LM, or CSM, it spreads out in a cone. By the time it reaches Earth, it’s a big spread of signal covering a wide area. The big dish is needed to collect all the data in that signal and focus it back again into a coherent signal. The more data, the bigger the dish needed to get it all. The signal being sent from Earth went through the same process of expanding into a wide cone, but contained far less information - pretty much just voice communication.

The command module’s S-Band antenna system consisted of four 0.8m dishes. TV was transmitted from the CSM, and it was felt that from lunar distances only the biggest dish would get decent quality TV, but the 85 foot dish was used on the return trip of Apollo 10 with excellent results.

This document describes dishes as small as 30 feet (just over 9 metres) at 11 stations in the tracking and communications network, 3 stations with 85 feet dishes (25 metres), and the largest 210 feet (64 metre) dishes at Goldstone and Parkes.

It describes how:

“The 85-foot antennas provide communications and tracking capabilities at lunar distances, while the 30-foot antennas are used during the earth-orbital and pre-injection phases of the missions and for carrier Doppler extraction during lunar descent and ascent to supplement data derived from the 85-foot-antenna sites.”

It also says:

“A 210-foot JPL antenna in conjunction with either the LM or CSM steerable antenna provides the necessary system gain to support color television at lunar distance. An 85-foot MSFN antenna is also adequate when the LM erectable antenna is used for down-link transmission of color television from the lunar surface.“

The document also discusses ‘herringbone’ interference, noticeable on the ground, caused by the presence of other information in the signal (such as telemetry) that better decoding equipment can remove, but obviously hasn’t been here.

So while bigger dishes are preferable, smaller dishes would do an adequate job of sending TV, and would obviously be more than capable of receiving voice alone.

Similar arguments are made relating to Soviet interception of S-Band data. Straydog and his ilk are keen to emphasise that the Soviets did not have the capability to intercept and decode S-Band, and there’s no evidence to support the idea that they did. As I discuss here, and as can be implied from the above, they certainly did.

This document discusses the equipment aimed specifically at intercepting signals from Apollo. This one, when translated, says:

“Under [M.S. Ryazansky's] leadership, a ground control complex was created to control Soviet manned and unmanned spacecraft for lunar exploration, which included two flight control centers, six ground and three ship control posts equipped with appropriate tracking stations, and located both on the territory of the Soviet Union and at certain points in the World Ocean. However, these facilities could not be used to receive information from the Apollo ships, since they operated in a different frequency range with signals that had a different structure. Therefore, at the suggestion of M.S. Ryazansky, it was decided to create a special control complex capable of receiving data from the Apollo ships. It was supposed to receive not only telephone (voice) and telemetry information from the American spaceships, but also television information.

It was decided to include in the control complex the TNA-400 antenna with a mirror diameter of 32 m, which was located in Crimea, near the city of Simferopol.

It was later used as a receiving antenna for the Saturn-MS radio engineering complex, which provided control of the Soviet automatic spacecraft for exploring the Moon, the Lunokhods, devices for delivering lunar soil to Earth, and lunar satellites.

To operate as part of the control complex, the TNA-400 antenna was equipped with a low-noise receiving device operating in the 13 cm range (the "S" range), in which the transmitters of the Apollo lunar modules operated. In addition, the complex includes: a demodulator for the group signal transmitted on the carrier frequency and signals transmitted on subcarrier frequencies, equipment for extracting voice, telemetry and television information, as well as equipment for displaying and controlling the complex.

The control complex, created in a short time by the enterprise in cooperation with several industrial enterprises, was ready to receive signals from the Apollo spacecraft in November 1968.

In order to track American lunar ships during their flight in orbits around the Moon and during landing on its surface, it was necessary to have ballistic data of these orbits to calculate target designations for the antenna. However, such information was not published by the Americans. Therefore, data on flight orbits were calculated by ballisticians based on the time of launch and arrival to the Moon of the Apollo ships, which were reported by American radio. Based on this data, targeting instructions were calculated for pointing the antenna, which were refined based on signals received by the control complex from the lunar ships.

This approach to calculating target designations made it possible to receive signals from the Apollos quite reliably. The task of searching for signals was made easier by the fact that the antenna pattern covered almost half of the Moon's disk.

The Apollo 8, 10, 11, and 12 spacecraft were tracked from December 1968 to November 1969.

All these ships received good quality telephone conversations between astronauts and Earth and telemetry information about the state of onboard systems. The received television signal was of low quality due to the insufficient energy potential of the radio link based on the 32-meter antenna.”

And they even produce a (poor quality, admittedly) view of Earth broadcast from the moon.

The still is from EVA-2, station 4.

Their own spacecraft also used S-Band transmissions.

In addition to Bochum and Baysinger, Italian and Dutch amateurs and observatories also intercepted signals from equipment and people on the moon - see my discussion here. It doesn’t matter that it’s only equipment: we have live TV footage of equipment being left on the moon, and that equipment transmitted information for many years afterwards. Photographs of the equipment in situ show other details that have been confirmed but subsequent unmanned probes but were not known about beforehand.

All stray and his fellow deniers have is, well, denial. Insisting (or rather getting AI to insist on your behalf) that something wasn’t done, or couldn’t be done without any actual evidence that this is the case proves nothing.

In a nutshell: you don’t need an massive dish to get S-Band. If you want TV signals equivalent to terrestrial broadcasting then yes you do, but just receiving the S-Band signal, no. If you are receiving an S-Band signal from an antenna pointing at the moon, and you lose that signal when you stop pointing at the moon, then take a wild guess at where that signal’s coming from. On top of that, there was enough VHF transmission, with nothing to stop it apart from a few molecules of air, leaking from suits and LM antenna to get back to anyone with a good enough aerial. There were plenty of those.

Amonst those amateurs are those documented in this June 1972 issue of QST magazine, who not only heard voice communications from Apollo 15 but used S-Band receivers to do it. The various set-ups are described in detail, and even describes building an S-band antenna using

“window screening, fishing string, and 1/2-inch aluminum tub”

So if they can do it with a relatively low budget 4m dish, Bochum could certainly manage it with their set-up.