The analog computer for the Nike missile system (2001) | Hacker News Reader

The analog computer for the Nike missile system (2001)

ed-thelen.org

112 pointsgreesil42 comments

I used to live near Sandy Hook in NJ. There was a Nike base there, but also several decades of various gun emplacements. They even secretly had nuclear warheads on the Nike Atlas missiles there to take out incoming bombers where the missiles were less accurate. No one in the towns around was told.

It’s an interesting historical place to walk around Fort Hancock as you see the batteries (no guns, sadly), and the Nike station.

The fortifications date from the civil war.

They have tours of the guns and missiles from time to time.

https://www.nps.gov/gate/planyourvisit/sandyhookniketours.ht...

https://home.nps.gov/gate/learn/historyculture/sandyhookpeop...

> They even secretly had nuclear warheads on the Nike Atlas missiles there to take out incoming bombers where the missiles were less accurate.

I think you mean Nike Ajax, although Ajax missiles adapted for nuclear warheads were actually called Nike Hercules.

Yes, sorry, going from memory, and just had that it was another A-something god in mind. You’re right, Ajax, not Atlas.

A few years back when I was at sandy hook the missile system gate was open. Some veterans who used to operate it gave us a free tour of the equipment and explained all about it.

I live near it now and can highly recommend a visit.

I’m still surprised how many New Yorkers are unaware of this half of the Gateway area and the summer accessibility via the ferry.. though of course it’s plenty popular nonetheless.

The trip down 36 can get brutal, but it’s a great bit of land all year round. Especially right up at the north end walking around the dunes. The inner beaches are beautiful and calm for young kids too. It’s a soft warm calm puddle in the summer, where the outer side gets rougher. The toddlers loved the inside and teens the outside.

Taught my wife and one of the kids to drive down there too. Up at the end are really good, mostly empty roads and parking lots for beginner drivers to practice on.

Have you toured the Battleship NJ? The firing computer is a mechanical analog computer. It's wild to see what can be done with some precision ground gears.

Never made it, but they have some great YouTube explanations I’ve seen.

Very interesting to see this here. I bought the Nike missile control unit years ago from some guy here in the Netherlands and it still sits in my garage. It has cool mechanical gyroscopes and microwave components. I disassembled most of the electronics modules and made a guitar amplifier from some of the pencil tubes. Sounds great and it's kind of cool I think, making a musical instrument out of a weapon.

Awesome! Did you document your teardown and guitar amp build anywhere? What a unique project. Would love to see it.

> Analog computers may seem to be "simple" or "like a toy computer", in fact they are powerful tools that were used during the 1950s and 1960s to design and test systems like ICBMs, supersonic aircraft and spacecraft.

this is indeed a very interesting quote that we -dealing with digital- often tend to forget.

As someone who builds essentially analog computers (modular synthesizers) this is just as viable a form of computation as anything else. Of course you have common analog pitfalls, like noise, drift, temperature stability, etc. but the results are nearly instant. And of course there is something magical about putting some analog voltages in and getting the result out as yet another analog voltage.

Not directly related, but brings to mind the training video for the fire control mechanical computers on US Navy ships: https://www.youtube.com/watch?v=s1i-dnAH9Y4

Also not directly related:

David A. Mindell, "Between Human and Machine: Feedback, Control, and Computing before Cybernetics" https://press.jhu.edu/books/title/1207/between-human-and-mac...

Absolutely epic book.

It feels a bit strange when you hear naval people from the 40s talking about 'computing a firing solution'. But these systems must have been reasonably sophisticated for 2 moving warships 10+ miles apart to stand any chance of hitting each other, allowing for wind, changes in atmospheric pressure, the earth's curvature, pitching and yawing and coriolis force.

Also these things existed prior to WWI so by 1940 they were several iterations in.

If you’ve never watched a video of one of these interceptor rockets, it’s worth a view. They take off at an insane speed.

https://en.wikipedia.org/wiki/Sprint_(missile)

https://www.youtube.com/watch?v=kvZGaMt7UgQ

Mach 10 in five seconds. Ablative cooling, due to the surface reaching 3500c from air friction.

The aerodynamic stress of that sort of acceleration close to sea level must be massive. it is a wonder they could make anything strong enough to survive it while being light enough to achieve that sort of acceleration.

On the plus side, the high temperature is only there for a few seconds. So it doesn't need to permanently withstand it, just for long enough to keep the systems operating.

we have multiple former Nike missle sites here in Anchorage. in a modern day city park, you can check out a missle stabilizer on interpretive display at the former launch command center turned cross country ski chalet. there are doors in that building that are like time portals to tha past. you go through an unassuming modern commercial steel door from a room where kids gather before weekly lessons into a world of concrete hallways with enormous blast doors welded open and narrow staircases leading down to lower levels with remnants of launch and other equipment.

ed-thelen.org is one of the most fascinating sites on the web to me, look around, its gigabytes and gigabytes of old missile tech.

If we lived in a peaceful world, building miniature missile systems to shoot down clay targets would be a hell of a hobby, but unfortunately, that seems like a bad idea given the ... world.

There are plenty of model rocketry competitions. For example to take an egg to a specific height and land it again by parachute in a specific time (unbroken). My son competed in the UKROC competition with friends: https://www.ukroc.com/

Building a rocket with guidance would be pretty cool. But would probably get you on a government watch list!

A miniature heat seeking rocket might be possible, like an early Sidewinder. Use it to shoot down model jet aircraft.

That would definitely be a fun project. I guess you would connect the sensor to a small processor which would drive steerable fins. Not sure RC aircraft give out much heat for a sensor to track though.

If necessary, use a cooperative target with an IR emitter.

It might be easier to ditch the Sidewinder-like custom IR sensor for a stock camera, and make up for this in software instead.

At the same time, I'm not sure if working on cheap guidance systems is the best idea at the moment - it could be used by Russias and North Koreas out there.

-Do bear in mind both Russia and DPRK has vast funds available for R&D; I'd be much more concerned about some three-letter agency knocking on your door, asking pointed questions about your innocent guided-missile pastime...

Looking how Russia still can’t make their own drones and needs to buy them from China and Iran - nah. They lost most of the potential inherited from USSR.

As for TLA - what’s wrong with asking questions? Especially when they might also provide you with a free legal advice wrt ITAR ;)

I accidentally and unintentionally violated ITAR a couple of decades ago. Free legal advice aside, it was hardly fun (not until afterwards...)

I definitely prefer not to end up on any government watchlists! I do worry a bit about my son's online searches. He is really into rocketry, not terrorism, but I wouldn't want to rely on the government to know the difference.

Related (a bit):

Notes on Nike Missile Site SF 88-L - https://news.ycombinator.com/item?id=22813836 - April 2020 (1 comment)

Nike Missile Sites of the San Francisco Bay Area (2001) - https://news.ycombinator.com/item?id=9956954 - July 2015 (48 comments)

You can still visit SF-88. It's open three days a week.[1] I've been there, and I've seen the analog computer. There are mechanical sequencers with motor driven cams. It's only partially electronic.

The blast doors and the missile elevator still worked, but the electronics and radar did not do much, although parts of the system could be powered up.

[1] https://www.nps.gov/goga/nike-missile-site.htm

I've hiked around there for decades and had no idea.

I'm totally going - thank you so much!

There is a Nike site in Florida as well. We tried to visit it in the summer, but it was closed.

So the short story is that the missiles were essentially radio controlled drones, radar measured the location of the target and the missile and from the ground the analog computer flies them together (or close enough that the bang will bring it down)

And the bang could be nuclear[1], so it didn't have to get that close.

[1] What could possibly go wrong?

Fallout. But you know, war never changes.

That's the only way they could possibly work: impossible to see through all that burning air at the front.

Each Sprint missile had an S-band transceiver and actively emitted signals that the ground systems could detect. They weren't just bouncing signals off the missile passively.

According to the radar operator I talked to, the coordinates from the search radar were transferred by hand to the guidance computer. And by transferred, they twiddled some knobs so the voltage sort of corresponded to the right values. Not even punch cards here. My millennial mind is blown.

I actually went to middle school in a former converted Nike missile radar site, we had the radar up and a lot of old hardware lying around. Definitely a cool experience as a kid.

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