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Inside a Titan missile guidance computer

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Re: Inside a Titan missile guidance computer

#21

Post by chrisseaton »

pvg wrote: post #20
dmix wrote: post #15

Earlier quoted context omitted.

Yes that’s correct, I meant compared to more controlled guidance by wire, radiation, satellite, etc. I phrased that improperly.

Fun tangent - the most unguided missile ever. https://en.wikipedia.org/wiki/AIR-2_Genie

> Lethal radius of the blast was estimated to be about 300 metres (980 ft). Once fired, the Genie's short flight-time [12 seconds] and large blast radius made it virtually impossible for a bomber to avoid destruction.

Why can’t you dive or climb just 150m in 12 seconds and be out of the blast range?

Re: Inside a Titan missile guidance computer

#22

Post by duxup »

chrisseaton wrote: post #21
pvg wrote: post #20

Earlier quoted context omitted.

Fun tangent - the most unguided missile ever. https://en.wikipedia.org/wiki/AIR-2_Genie

> Lethal radius of the blast was estimated to be about 300 metres (980 ft). Once fired, the Genie's short flight-time [12 seconds] and large blast radius made it virtually impossible for a bomber to avoid destruction. Why can’t you dive or climb just 150m in 12 seconds and be out of the blast range?

I suppose you have to be sure of the rockets detonation point to know if you are moving away in the right direction. I'm not sure that is a thing you could be sure of the moment the rocket is fired (or if you would know).

Also the target (at least initially) was large formations of Tupolev Tu-4s who can only climb 15m/s. So that puts them right on the edge, but assuming more than one rocket is fired or that they simply don't always have time to realize it was fired quickly enough... that probably does it.

Re: Inside a Titan missile guidance computer

#23

Post by pvg »

chrisseaton wrote: post #21
pvg wrote: post #20

Earlier quoted context omitted.

Fun tangent - the most unguided missile ever. https://en.wikipedia.org/wiki/AIR-2_Genie

> Lethal radius of the blast was estimated to be about 300 metres (980 ft). Once fired, the Genie's short flight-time [12 seconds] and large blast radius made it virtually impossible for a bomber to avoid destruction. Why can’t you dive or climb just 150m in 12 seconds and be out of the blast range?

Why 150m? It says 'radius' so if the missile is on an intercept course, 150m is not going to help you. Beside the difficulty of knowing the exact launch time and having to move a 50mx50m 180 ton bomber in fewer than 12 seconds.

Re: Inside a Titan missile guidance computer

#25

Post by rootusrootus »

rgovostes wrote: post #6

I visited the Titan Missile Museum in Tucson, AZ, where you can see the control room from which the missile could have been launched. > At launch, orders from the National Command Authority would have specified one of three pre-programmed targets which, for security reasons, were unknown to the crew. ... Target 2, which is classified to this day but was assumed to be within the borders of the former Soviet Union, was…

> I wonder if the tape was original

I'd be very surprised. We used punched tape for initializing our crypto gear when I was in the Air Force, and it was accounted for carefully and destroyed promptly. Even more carefully than our regular classified documents, though maybe that was just a culture thing. I can't imagine them just giving it over to a museum.

Re: Inside a Titan missile guidance computer

#26

Post by tedivm »

chrisseaton wrote: post #21
pvg wrote: post #20

Earlier quoted context omitted.

Fun tangent - the most unguided missile ever. https://en.wikipedia.org/wiki/AIR-2_Genie

> Lethal radius of the blast was estimated to be about 300 metres (980 ft). Once fired, the Genie's short flight-time [12 seconds] and large blast radius made it virtually impossible for a bomber to avoid destruction. Why can’t you dive or climb just 150m in 12 seconds and be out of the blast range?

Fighters and interceptors can, bombers can't.

Re: Inside a Titan missile guidance computer

#27

Post by blueatlas »

kens wrote: post #11
kipchak wrote: post #9

If you're interested in the history of the Titan missile program and US nuclear program in general I recommend "Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety".

I definitely agree with your recommendation. Much of that book describes the Titan missile that blew up in 1980 after someone dropped a wrench socket that punctured the rocket's fuel tank, throwing the 9 megaton warhead 100 feet. (The warhead did not detonate.) What I didn't realize until I visited the Titan museum near Tucson is that it wasn't a regular wrench socket, but a big, fist-sized 8-pound socket. This made…

American Experience (PBS) did one of their documentaries on this event. It is very well done.

Prior to the socket being dropped, there was a change order issued to use a new type of socket that would not dislodge from the wrench. As I recall, the two technicians tasked with the repair didn't have the new type of socket, but proceeded into the silo anyway.

Re: Inside a Titan missile guidance computer

#28

Post by djmips »

kator wrote: post #7

I was just thinking, imagine trying to use a modern-day smartphone for this. So much complexity how could you be sure the missile would even get off the ground. There is a big advantage to systems that engineers can mostly "keep in their heads". Very few systems are that way these days.

A Teensy 4.0 just as an example which is much more like this. Has a bunch of general purpose I/O; it's quite powerful; and you can essentially keep it in your head.
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