It’s a strange kind of love.

Techno-archeologist Ken Shirriff has started the inspection of some of my historic space artifacts. He is the fellow that helped the team that rebooted the Apollo Guidance Computer and got an old IBM punch-card mainframe to do some bitcoin mining. When peering into the black box of space history, what better place than the literal black box of a Titan II nuclear ICBM guidance computer? And I have some HDR photos to share of the big boy in the silo.

In the FV Space Collection, I have the 1978 Titan II flight computer, IMU and early 1959-era Titan I TARS (Three Axis Reference System) as well as complete computer + IMU stacks for the Lunar Module and Space Shuttle. Here we dive into the 80-pound Titan guidance computer built by General Motors’ Delco Division. Pop the lid, and we find a 24-bit processor spread across multiple boards full of TTL mystery chips and a beautiful unfolding accordion of magnetic core memory arrays (more of Ken’s photos below).

The Titan II was the largest nuclear missile ever made by the U.S. It seems a bit cheeky to use seven digits for the serial number. I have lucky #0000069

9 responses to “Titan II / IIIC Flight Computer — Universal Space Guidance System (USGS)”

  1. jurvetson Avatar
    jurvetson

    Peering inside the black box… From Ken’s postAnd pulling out the core memories. The Titan II ICBM / IIIC rocket guidance computer used magnetic core memory. Each bit is a tiny ferrite ring threaded on wires. Unlike most core stacks, this one used a flexible circuit board, so it opened like a book for repair. Two stacks, each with 8K words of 24 bits + parity. From another Ken postAlthough the planes are mounted on the flex PCB, most of the core plane wiring is individual loose wires that go from board to board. According to GM’s patent, it should be possible to unfold the whole core stack into a single long strip. Just above the core planes are sense amplifier chips to read a bit from the plane. To prevent noise, a twisted pair (red/green) goes from the core plane’s sense line to the amplifier. The white chip is a resistor network to bias and terminate the sense line, connected to the black chip which is the amplifier. One advantage of the flex PCB is that the amplifiers are very close to the cores (as opposed to other core stacks where the amplifiers are on separate boards outside the core stack) so it reduces noise pickup.And the bad boy in the silo, some of my photosNuclear Missile SiloThis missile is from underground complex 571-7, all that remains of the 54 Titan II missile sites that were on alert 24×7 across the United States from 1963 to 1987. This was the era of MAD. The infrastructure to protect this missile is massive, as its intended use was a retaliatory strike — after most of the U.S. was destroyed, these missiles needed to guarantee the destruction of the attacker in return.Titan II Missile WarheadSo, the entire underground launch complex was capable of only being used once… and ideally never.Here’s an interesting historical summary of the Titan program, the medium-lift predecessor to the Atlas/Delta era."Whatever trouble NASA managed to get itself into, the Titan was still there to keep its planetary exploration program going."

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  2. sbove Avatar
    sbove

    Long way from Dayton and battery ignition systems for cars to Titan guidance computers made in Goleta, CA! – "Delco came from the Dayton Engineering Laboratories, founded in Dayton, Ohio, by Charles Kettering and Edward A. Deeds in 1909.[1] Delco was responsible for several innovations in automobile electric systems, including the first reliable battery ignition system and the first practical automobile self-starter." – en.wikipedia.org/wiki/Delco_Electronics

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  3. sbove Avatar
    sbove

    Why 24 bit? Targeting accuracy?

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  4. sbove Avatar
    sbove

    The Delco story reminds me of Motorola…co-founded by Bill Lear (a Tesla fanatic) and his partner Paul Galvin to make the first car radios that didn’t suffer from horrible alternator interference. Their flagship product was the "Motorola"… "The product was such a success that Galvin changed the name of the company to Motorola." Most folks also have no idea Bill Lear invented and profited greatly from the 8-Track cassette system. He loved music in his cars and planes! He also invented tech that eventually became the basis for the tuning dials found on most TVs for 30 years (pre-set channels tuned by small coils made of ultra-thin "Litz wire" with high surface conductivity at RF), and the first practical aviation "radio compass" or ADF (automatic direction finder) which was made in several models by Lear Avia in Dayton before being sold to Bendix. en.wikipedia.org/wiki/Bill_Lear

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  5. oklo Avatar
    oklo

    Remarkable photos of the silo and detail of the core memory on the guidance computers. Eric Schlosser’s book Command and Control — http://www.amazon.com/Command-Control-Damascus-Accident-Illusion... — provides a gripping narrative of the precarious demands presented by the need for continual 24-7 readiness to launch on warning.

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  6. jurvetson Avatar
    jurvetson

    Thanks Oklo and Stephen! Ken posted additional shots of the strange beauty inside.

    Reply
  7. precious amount Avatar
    precious amount

    I’m interested in system safety. I guess that’s oxymoronic in this case. Thanks for sharing these wonderful photos of technology history! What a gem!

    Reply
  8. jurvetson Avatar
    jurvetson

    And now with a detailed blog post writeup: http://www.righto.com/2020/03/inside-titan-missile-guidance-comp...

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  9. jurvetson Avatar
    jurvetson

    And I just found a video of the disassembly (and the gem of a core memory module inside).

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