Tuesday, July 21, 2009

40 Years Later: Moon Communications Questioned in Blogsphere

In honor of the 40th anniversary of Neil Armstrong's first walk on the moon, I thought I would find a little microwave trivia from the Apollo 11 mission. My search produced the following exchange from an online forum (www.2012forum.com). I thought it was worth sharing with all of you. Enjoy!

"I have a MA in Communications/Computer Engineering.(IBM Veteran Engineer/Inventor) One thing that I have always questioned in the Moon landings was:In communications there is a thing called Attenuation, weakened signals even when used in radio waves. When an average radio wave travels here on earth, there are many even thousands of Transponders(Amplifiers) that take that signal and amplify it, otherwise the signal is lost.. When you make a call to say Europe, you will get that very same attenuation and delay of about 1-2 seconds, if you have a good connection there may be a one second lag. How was it possible to hear voice, data, and video and greater than 3GSpeed when that technology was not even present in Early 1969 - 1974. Microwave Communications was present but how is a signal amplified from the Moon in full duplex back to Earth without amplification? This is impossible without a Microwave Tower/ Transponder on the Moon! It is well known the the Moon Capsules had the basic computing/ and processing power of a modern day microwave oven. A Modern Automobile has more computing power than the lunar module itself (Google space capsule computing); so how was it possible to receive in Real Time, Voice, Data & Video from (221,600 miles) and greater than 3GSpeeds from a distant at perigee and 406,997 kilometers, WITHOUT AMPLICATION - IT IS IMPOSSIBLE! This from of Communication Technology Did not exsist in 1969-1974, Even if it did exsist, there would have to be an array of Towers on the Moon and Transponders in the line of the path to receive these signals. Per Every 1000 Mi a basic radio signal will need amplification by way of a Microwave, Transponder Tower and or Satellite Amplification. There are absolutely NO Satellites orbiting the Moon, as any modern Communications Engineers will tell you, unless they are gullible and want to believe just in the name of being a Patriot for a lie. Again it is impossible to have Voice, Video & Data at Real Time with less than 1 Second Delay as many NASA VIDEOS PORTRAY from a distance of 221,600 miles (what they claimed to use on ALL NASA MOON MISSIONS) these supposed Voice, Data & Video signals would not reach the Moon target for Weeks and even Months Without Proper Amplification. Lets get real here...My 2 Cents,"

by Artemeus

This conspiracy theory and explanation of microwave communication systems was countered with the following response:

"The attenuation might be a problem but it is vacuum between Earth & Moon - many of the reasons for attenuation on Earth don't exist. The Moon doesn't have a magnetic field so the siganl would leave there pretty much at original strength. It has only the can Allen belts & about 100kms of atmosphere to travel.

There's no reason the signal would take 'Weeks and even Months' or even days - there is no difference between a strong signal or a weak one in speed. The signal would take 221,600/186,282 (if I recall my school day SoL figure) seconds each way, no matter how strong it was.

The delay you experience in Earth transmission of phones has to do with the equipment processing going on - the signal gets picked up & resent several times on it's journey to the receiver & at several points the header has to be read to decide where it is going. There's also contention - it is a packet system so the receiver has to wait for packets to arrive to before being able to reassemble them into coherent speech.

Radio is not like that at all - it is an analogue system & travels across the line of sight in fractions of a second. It also bounces off layers in the atmosphere, which is one of the reasons amateur radio guys are so pissed about the Sun right now - no sunspots means some of their transmissions simply don't work. While signal strength might be a factor, I don't think the transmitter on the lander would have too much trouble boosting a signal to either the orbiter (does anyone know if we lost signal when the orbiter went behind the moon?) or Earth. Given the vacuum we're talking the equivalent of sending a signal about maybe 300 miles as far as signal loss goes."

by Acolyte

I read a statistic that 6% of the population believes the moon landing was a hoax. Anyone else want to shed light on the science at work here?

Oh and here's that story on the microwave transmission of the landing:

It was 1969, and a moment by which humanity would come to measure itself flickered from a wall of monitors before Bruce Ekert’s eyes.
As Neil Armstrong stepped from the lunar module Bruce, 23, prayed that the signal beaming the pictures to earth wouldn’t fail. It was his job, at the Honeysuckle Creek transmission station near Canberra, to make sure it didn’t.
“We were told not to touch anything,” he said, “unless it stopped working. Sort of an ‘if it ain’t broke, don’t fix it’ approach. So we sat there drinking tea, just hoping nothing would go wrong.”
Now Bruce, his face filled with computer glare, is scrolling through a web page in his Forster flat.
“There he is,” he says, swivelling in his seat. On the screen is a black-and-white photo of a man in thick glasses glued to a monitor.
“That’s the moment the first person on Earth saw pictures of the landing. His name’s Ed von Renouard.”
Bruce, a couple of rooms across, absorbed the same vision a split-second later. Doesn’t it follow, then, that he was among the first dozen or so witnesses of the moon landing?
“Yeah, I would’ve been in about the first 20,” he says.
Monday is the 40th anniversary of the day Armstrong and Apollo 11 crewmates Buzz Aldrin and Michael Collins became the most famous men on Earth.
NASA had decided at the last minute it would be worth the cost of sending cameras to capture it, and more than six hundred million huddled around TVs and radios to hear the first words crackle from another world.
Armstrong’s “One small step for a man, one giant leap for mankind” was scripted. Aldrin’s description of “Magnificent desolation” was his own.
But, days earlier, NASA hit a snag.
“They realised that, at the time of the landing, the moon would be on our side of the Earth,” Bruce says.
“America would be out of communications. So they looked for tracking stations that could pick it up. There was one at Parkes, and one at Honeysuckle.”
It’s worth noting that the Parkes station, romanticised in Rob Sitch’s comedy The Dish, was never actually the sole link to the mission. There was always additional contact through Honeysuckle and Goldstone, California. But Parkes was in a position, at one point, to provide the best signal, thus briefly becoming the focal point of the broadcast.
Bruce and three other technicians had set up a microwave link between Honeysuckle, the Apollo 11 spacecraft and mission control.
It would be wrong to say a failure of Bruce’s monitors would’ve been a complete disaster. There was a backup connection. But it would have been one giant leap toward losing the telecast.
“When Honeysuckle was chosen as one of the transmission stations, it had pretty old infrastructure. Even for the time,” he says.
“It was old valve equipment, not the new transistors. It could fail anytime. It could get hot and” - Bruce clicks his fingers - “just die.”
As the pictures beamed through, neither Bruce nor his workmates spoke of making history, or watching it unfold.
“There was a cheer when it happened, but more of that feeling came later when we watched the news reports,” he says.
“We didn’t see the celebrations happening like everyone else. And we didn’t know all the children had been given time off school to watch the landing.”
With a 40th anniversary reunion – “I haven’t seen some of those people since 1969” – coming up, Bruce wants more credit for the Australians who brought the moment into living rooms and moved Walter Cronkite to tears.
“There were about 100 Australians behind the scenes, and we worked as hard as anyone for very little recognition,” he says, looking out at the traffic below.
The giant dish that loomed over Honeysuckle and skimmed history’s most famous pictures across the globe is now at Tidbinbilla Deep Space Tracking Station, ACT. It’s about to be decommissioned.
Asked if he hopes the dish will be preserved, Bruce chuckles.
“It’s 26 metres across. You’d need a big museum,” he says. But then he folds his arms over his grey woollen jumper, and smiles faintly.
“But I used to think it was quite a sight, that enormous dish turning across the sky.”

1 comment:

  1. Acolyte is an idiot and doesn't understand radio transmission theory. Education is a wonerful thing.