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Old 15-05-2019, 11:26 AM
gary
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Project Artemis now has a name but not all the funding - NASA - Moon walk 2024

Well they don't have the funding, but NASA has at least got a name for their 2024 return to the Moon project.

They have also pledged to get a female astronaut to the Moon for the first time.

Quote:
Originally Posted by AFP
Bridenstine said the mission was named Artemis after the Greek mythological goddess of the Moon and twin sister to Apollo, namesake of the program that sent 12 American astronauts to the Moon between 1969 and 1972.
Story here :-
https://www.afp.com/en/news/826/nasa...on-doc-1gf3dv1
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Old 15-05-2019, 06:31 PM
Dennis
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Thanks Gary - I cannot quite believe that humanity will be returning back to the Moon in such a short time, I thought we had lost both the will and the appetite.

Cheers

Dennis
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Old 15-05-2019, 07:08 PM
gary
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Quote:
Originally Posted by Dennis View Post
Thanks Gary - I cannot quite believe that humanity will be returning back to the Moon in such a short time, I thought we had lost both the will and the appetite.
Thanks Dennis,

Though I believe it would be more accurate to say that "the United States"
or "the United States taxpayer" lost both their will and appetite to return,
rather than humanity.

After all, it was they who set it as a national goal, they who engineered it
and they who paid for the entire bill.

No other country had either the resources, money or absolute willingness
to do it.

Not even the Soviet Union saw it through and quickly abandoned their
half-hearted attempt after the N1 failures and never attempted to try
it again.

When we cast our minds back to the 60's and 70's, it was a period of
social unrest in the United States and elsewhere.

Vietnam, the civil rights movement and poverty were more pressing
concerns for the American public at large. Particularly once the goal
of landing a man on the moon had been achieved.

Meanwhile, Richard Nixon saw an early end to the Apollo project and
changed NASA policy in such a way that it would shape what it did for
decades. Nixon wasn't the biggest fan of the space program.
Historians say what he said publicly about it and what he
thought personally about it were two different things.

Under Nixon, the space program was made to become a domestic policy
that had to compete with other domestic policies and after the Apollo 11
walk was no longer of political interest to him.

It also lead to the decision to put the emphasis on low earth
orbit missions, the Space Shuttle and so on. A legacy that continues
to this day.

With each passing day, it only makes that achievement of 50 years ago
even more impressive in its skill and audaciousness.

As Mike Collins himself said, after the Apollo 11 success, he was touched
by the number of people he met around the world that said "we did it"
rather than see it as a purely American success. So in that sense, it very
much was perceived as a triumph for humanity.
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  #4  
Old 15-05-2019, 08:41 PM
Dennis
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Quote:
Originally Posted by gary View Post
Thanks Dennis,

>snip

With each passing day, it only makes that achievement of 50 years ago
even more impressive in its skill and audaciousness.

As Mike Collins himself said, after the Apollo 11 success, he was touched
by the number of people he met around the world that said "we did it"
rather than see it as a purely American success. So in that sense, it very
much was perceived as a triumph for humanity.
Thanks Gary, that pretty much sums it up.

Here are the contents of one of the Exhibit Display Cases from the NASA Exhibition running in Brisbane right now.

Note the Slide Rule...who would know what one of these is today.

Also note the "advanced computer technology" of that era as described on the associated display placard ...

Cheers

Dennis
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  #5  
Old 15-05-2019, 09:36 PM
gary
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Quote:
Originally Posted by Dennis View Post
Thanks Gary, that pretty much sums it up.

Here are the contents of one of the Exhibit Display Cases from the NASA Exhibition running in Brisbane right now.

Note the Slide Rule...who would know what one of these is today.

Also note the "advanced computer technology" of that era as described on the associated display placard ...

Cheers

Dennis
Thanks Dennis,

I've been following the videos of this group of individuals who have been
attempting to restore an Apollo Guidance Computer (AGC) so that it
can run code again.

Their goal was try to do this before the 50th anniversary of Apollo 11.

https://www.youtube.com/watch?v=2KSa...lisi_x7-Ut_-w7

Part 7, where they were attempting to find a fault in a potted core memory
module showcases their determination :-
https://youtu.be/uyxQmb2u6Hk
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  #6  
Old 16-05-2019, 09:37 AM
Dennis
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Quote:
Originally Posted by gary View Post
Thanks Dennis,

I've been following the videos of this group of individuals who have been
attempting to restore an Apollo Guidance Computer (AGC) so that it
can run code again.

Their goal was try to do this before the 50th anniversary of Apollo 11.

https://www.youtube.com/watch?v=2KSa...lisi_x7-Ut_-w7

Part 7, where they were attempting to find a fault in a potted core memory
module showcases their determination :-
https://youtu.be/uyxQmb2u6Hk

Wow, so the owner of the AGC worked on the LEM and purchased 2 tons of discarded NASA Apollo HW at a warehouse somewhere, found the AGC and the young guy testing the Apollo AGC core memory has also built an AGC Emulator.

Astonishing to see their demo of how ferrite core memory works, the wiring and stacking in those modules blows my mind. Then the Formal Peer Design Review considers them not suitable for flight…Where was Silicon memory when you needed it.

And, reading it is destructive. Wow.

How on earth DID they get to the Moon…and back.

Cheers

Dennis
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  #7  
Old 16-05-2019, 10:49 AM
gary
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Quote:
Originally Posted by Dennis View Post
Wow, so the owner of the AGC worked on the LEM and purchased 2 tons of discarded NASA Apollo HW at a warehouse somewhere, found the AGC and the young guy testing the Apollo AGC core memory has also built an AGC Emulator.

Astonishing to see their demo of how ferrite core memory works, the wiring and stacking in those modules blows my mind. Then the Formal Peer Design Review considers them not suitable for flight…Where was Silicon memory when you needed it.

And, reading it is destructive. Wow.

How on earth DID they get to the Moon…and back.

Cheers

Dennis
Hi Dennis,

It's pretty cool.

I have attached a couple of snapshots I just took of a core memory board
I own which came out of an IBM 360/50 mainframe from the 1960's.

When it was new, it would have cost some eye-watering amount of money.

This has higher density than the core memory that was in the AGC
and the cores themselves are even too small to see naked eye.

Where you mentioned reading was destructive, that is right.
Three wires pass through each core. One to flip it to the '1' state,
another to flip it to the '0' state and a sense wire.

So to read a bit back, you would attempt to flip it to the '1' state whilst
monitoring the sense wire. If it was already in the '1' state then the
magnetic flux would barely change and the sense wire would detect
nothing. If it was in the '0' state and you just flipped it to '1', you would
detect the change in flux in the sense wire and then you would have to
restore it by flipping it back to '0' again.

It did have one enormous advantage over the DRAM sitting in your
PC right now in that if you cut the power it would retain its contents.

Remarkably the AGC firmware was woven into the core as a form of
read-only memory (ROM).
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Old 16-05-2019, 11:06 AM
gary
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Hi Dennis,

If you have not read it already, I highly recommend "Digital Apollo"
by David A. Mindell.

Mindell is Professor of Aeronautics and Astronautics, and Dibner Professor of the History of Engineering and Manufacturing at the Massachusetts Institute of Technology.

As you will be aware, MIT played a key role in designing the guidance systems, computers and software that took us to the moon.
Mindell's book describes the philosophy and design that that went into the pilot-machine loop.

https://www.amazon.com/Digital-Apoll.../dp/B0031AI0X0
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  #9  
Old 16-05-2019, 05:47 PM
Dennis
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Quote:
Originally Posted by gary View Post
Hi Dennis,

It's pretty cool.

I have attached a couple of snapshots I just took of a core memory board
I own which came out of an IBM 360/50 mainframe from the 1960's.

When it was new, it would have cost some eye-watering amount of money.

This has higher density than the core memory that was in the AGC
and the cores themselves are even too small to see naked eye.

Where you mentioned reading was destructive, that is right.
Three wires pass through each core. One to flip it to the '1' state,
another to flip it to the '0' state and a sense wire.

So to read a bit back, you would attempt to flip it to the '1' state whilst
monitoring the sense wire. If it was already in the '1' state then the
magnetic flux would barely change and the sense wire would detect
nothing. If it was in the '0' state and you just flipped it to '1', you would
detect the change in flux in the sense wire and then you would have to
restore it by flipping it back to '0' again.

It did have one enormous advantage over the DRAM sitting in your
PC right now in that if you cut the power it would retain its contents.

Remarkably the AGC firmware was woven into the core as a form of
read-only memory (ROM).
Thanks Gary - but that begs the question, who assembles the wiring looms and multi-plane boards for the core memory boards in Argo Navis...

It was interesting to see the re-furb team playing around with the various input signal levels to obtain a clean core switching profile, noting that they were also concerned about the heating effects, so had to use short pulses.

I am now even more enthralled by and astonished with the Mercury, Gemini & Apollo program achievements.

Time to visit the museum again methinks.

Cheers

Dennis
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  #10  
Old 16-05-2019, 05:49 PM
Dennis
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Quote:
Originally Posted by gary View Post
Hi Dennis,

If you have not read it already, I highly recommend "Digital Apollo"
by David A. Mindell.

Mindell is Professor of Aeronautics and Astronautics, and Dibner Professor of the History of Engineering and Manufacturing at the Massachusetts Institute of Technology.

As you will be aware, MIT played a key role in designing the guidance systems, computers and software that took us to the moon.
Mindell's book describes the philosophy and design that that went into the pilot-machine loop.

https://www.amazon.com/Digital-Apoll.../dp/B0031AI0X0
Thanks Gary - heading over there right now, quite a steal at $20 on Kindle.

Cheers

Dennis
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Old 16-05-2019, 06:24 PM
gary
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Quote:
Originally Posted by Dennis View Post
Thanks Gary - but that begs the question, who assembles the wiring looms and multi-plane boards for the core memory boards in Argo Navis...
Hi Dennis,

LOL.

In that case you may be interested in this 1965 short documentary
that was part of a regular MIT series called the Science Reporter.

In this episode, MIT reporter John Fitch visits the MIT
Instrumentation Laboratory and Raytheon whilst they are assembling
the Apollo computers.

In particular I draw your attention to the 20m45s mark where they
show the assembly of the core memory modules.

It was true then and largely true today that the most patient, skilled
and dexterous operators on a factory floor where some intricate work
is involved tend to be women rather than men.

Note how they hand stitch the core.

Video here :-
https://youtu.be/ndvmFlg1WmE

At the same time all this was going on, skilled woman at the
International Latex Corporation, the same company that made
Playtex bras and girdles, hand-stitched the Apollo EVA spacesuits.
Arguably up to that time, the most sophisticated and possibly most
expensive garments ever made.

By the way, there are other episodes in the MIT Science Reporter series
from the same period on YouTube, including others devoted to
Apollo.

For example, this one where he speaks with none other than Thomas
Kelly, the engineer who led the team at Grumman, on building the
Lunar Excursion Module, is absolutely fabulous.
https://www.youtube.com/watch?v=ikYHsXF_k0Q
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  #12  
Old 17-05-2019, 08:24 AM
Dennis
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Thanks Gary, but Whoops – though I had lost the colour calibration profile on my monitor, it was all in B&W.

I loved the pre-PowerPoint diagrams, charts and illustrations and the concept of using San Francisco Bay as a landmark for the navigation computer.

I was also so surprised to see a motorised GoTo operation commanding the on-board telescope back in 1965, well before the modern era of GoTo mounts.

The comment about the Apollo Computer being similar to much larger ground-based computers “that are dominating our lives today” was quite humorous, given this was back in, wait for it… 1965!

The DSKY Verbs and Nouns input method wasn’t lost on me given that this is what we do today; Print: DocumentName, Open: Filename, Send: E-mailMessage, etc.

It was very interesting to see how they tested the discrete components, the metal can semi-conductors going through accelerated burn-in, environmental shock at 20,000G, thermal cycling to account for the extremes of temperatures, etc. And, if 1 in the test batch failed, the whole batch was rejected, and a new batch submitted for test. This obviously predated the modern Quality Management movement, whereby conformance to requirements are designed and built into the product, rather than just trying to “test quality” at the end.

Loved the automated wiring and welding machines that created the Logic Sticks and the hand weaving of the ferrite cores. The machinery to index the correct location for the assembler to pass the wire through the core was quite remarkable, controlled by IBM punch cards.

It took 512 cores and over mile of wire to represent over 65,000 pieces of information. Gulp!

Another mindblower was seeing the density and complexity of the wiring pattern at the back plane of the memory tray assembly which required a machine to route the wires according to a program.

Those were the days eh!

Cheers

Dennis
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