"13 Minutes to the Moon"

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rwilkinson
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"13 Minutes to the Moon"

Post by rwilkinson » Mon May 13, 2019 1:09 pm

BBC World Service has compiled a series of podcasts to commemorate the 50th anniversary of Apollo 11.
The first 45-min episode has just been released: https://www.bbc.co.uk/programmes/w13xttx2

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Re: "13 Minutes to the Moon"

Post by rwilkinson » Sat May 25, 2019 6:49 am

The second episode https://www.bbc.co.uk/programmes/w3csz4dk features interviews with some of the young men who operated the Mission Control Center and explains how their response to the Guidance Computer's infamous Program Alarms was only formulated after the final practice simulation, a fortnight before the launch.

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Re: "13 Minutes to the Moon"

Post by rwilkinson » Mon May 27, 2019 3:23 pm

The third episode is now available: https://www.bbc.co.uk/programmes/w3csz4dl

This covers the extraordinary design of the Grumman Lunar Excursion Module ("it looks like an angry creature with four legs, staring at you, daring you to call it ugly!") and its landing procedures. As Neil Armstrong said "there were a thousand things to worry about in the final descent!" I'd never realised that the LEM's Descent Engine was the first-ever rocket engine designed with a throttle (to control the descent rate).

The programme features an interview with astronaut Charlie Duke, who was CapCom on Apollo 11 and later the LM Pilot on Apollo 16. He said "I probably landed on the Moon 2000 times in simulation - but I crashed 1000 times too!"
They also talk to one of the Grumman technicians who had to retro-fit extra thermal insulation onto the Eagle's lower stage and legs just a few weeks before launch - when it was already stowed on top of its Saturn V!

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Re: "13 Minutes to the Moon"

Post by rwilkinson » Wed Jun 05, 2019 2:53 pm

Episode Four includes the catastrophic fire of Apollo 1, and then the successful test-flight of Apollo 7 just 21 months later:
https://www.bbc.co.uk/programmes/w3csz4dm

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Re: "13 Minutes to the Moon"

Post by rwilkinson » Mon Jun 10, 2019 11:00 am

Episode 5 is all about the Apollo Guidance Computer - the "fourth astronaut" on each mission.
This was the world's first portable digital programmable computer, and the first electronic flight-control system.
As well as shrinking a computer from the size of a room down to that of a couple of shoe-boxes, they also had to make it ultra-reliable, using the emerging technology of Integrated Circuits.
The team at MIT also had to develop the software to run on a machine with 76KBytes of memory (only 4K of which was RAM), which then had to be woven into magnetic-core "rope" memory.

I've since found an interesting simulation of this remarkable machine: http://svtsim.com/moonjs/agc.html

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Re: "13 Minutes to the Moon"

Post by rwilkinson » Tue Jun 18, 2019 7:17 am

Episode 6 https://www.bbc.co.uk/sounds/play/w3csz4dp covers Apollo 8, and includes interviews with astronauts Frank Borman, Lim Lovell & Bill Anders.
This was such an audacious mission that Anders told his wife that he had a one in three chance of not making it back alive - but this was about the same as if he'd been flying in Vietnam, so they "just got on with the job".
As we know, it was a success, and their Christmas message from the Moon and historic Earthrise photo helped to "save 1968".

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Re: "13 Minutes to the Moon"

Post by rwilkinson » Mon Jun 24, 2019 10:40 am

Episode 7 is all about the "third man": Apollo 11's Command Module Pilot Mike Collins:
https://www.bbc.co.uk/sounds/play/w3csz4dq
He says that his participation in the mission was "10% shrewd judgement and 90% luck" - and only got into NASA's astronaut selection at the second attempt.
The programme includes a number of readings from his classic book "Carrying the Fire": https://www.amazon.co.uk/gp/product/1509896570
He reckons that Neil Armstrong was "the best possible choice - the ideal man to represent our country or planet, in being the first to walk in the Moon". But when Armstrong and Aldrin set off for the Moon in the Eagle, Collins "felt like a father whose teenagers have taken the car out alone for the first time"! Alone in the Command Module, he had no fewer than 18 contingency plans to cope with possible emergencies below.

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Re: "13 Minutes to the Moon"

Post by rwilkinson » Mon Jul 01, 2019 1:39 pm

Episode 8 takes us through the "Powered Descent" phase of the flight:
https://www.bbc.co.uk/sounds/play/p07fgvq2
As well as the audio-stream from NASA's archives we also hear interviews with Flight Director Gene Kranz and his team from Mission Control, particularly the Capsule Communicator Charlie Duke.
I'd read several times about the patchy communications and telemetry links from the Lunar Module, but it's fascinating to hear the tension in their voices. We also hear about the cause of the 1200-series Program Alarms from the computer and how they mitigated them.
Kranz says that it was "miraculous" to watch how his team responded to these challenges.

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Re: "13 Minutes to the Moon"

Post by rwilkinson » Tue Jul 09, 2019 7:56 am

Episode 9 covers the landing itself:
https://www.bbc.co.uk/sounds/play/w3csz4ds
I was interested to hear about the Landing-Point Designator which Armstrong used to visualise his landing site whilst in flight. It was merely a graduated scale etched onto his window, past which he could sight the terrain as Aldrin read the projected target angle off the computer display and called it out to him.
It also features Flight Controller Bob Carlton's famous stopwatch, from which he estimated that they had just 18 seconds' of fuel left on landing.

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Re: "13 Minutes to the Moon"

Post by rwilkinson » Mon Jul 15, 2019 6:55 pm

In Episode 10 we hear an annotated version (with Kevin Fong's detailed explanations) of the voice recordings of the descent and landing:
https://www.bbc.co.uk/programmes/p07grjp4
And this includes the root-cause of the 1200-series Program Alarms: the astronauts having turned on their Rendezvous Radar, which led to the computer overloads. They hadn't used this during their simulations, which is why the computer hadn't thrown up those errors before.
The programme concludes with a set of interviews with some of the protagonists (including Mike Collins and Charlie Duke), considering the legacy of Apollo 50 years on.

Then Episode 11 runs the CapCom's audio Loop uninterrupted, exactly as Charlie Duke heard it at the time:
https://www.bbc.co.uk/programmes/p07grkvh
You can hear in the first few minutes how poor the signal was from Eagle in the early part of the Powered Descent.
If like me you found the last half-hour of yesterday's Cricket World Cup Final nerve-jangling, this is on a different scale entirely!

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