Engineering a real-life "Star Wars" AT-AT


At Innovation News Daily, science journalist Jeremy Hsu explores what it would take to make Mike Koehler's AT-AT For America dream a reality.

Making a modern-day robotic walker is not impossible, said Heiko Hoffman, a robotics expert at HRL Laboratories in Malibu, Calif., but it easily could cost $100 million or more.

"[The cost] would likely be much higher for a seriously armored vehicle," Hoffman said of the cost. "If we just build an AT-AT that looks cool, it could be much cheaper."

The AT-AT walker lumbers along like a mechanical elephant, lifting just one foot at a time. That "statically stable" walking style works for a heavy vehicle, because the center of mass always sits above a "triangle" created by keeping three feet on the ground, Hoffman said.

But building a huge 50-foot-tall walker is challenging because structural strength does not increase on par with sheer mass, Hoffman explained. A vehicle 10 times the size of a smaller model might have a supporting beam 10 times larger, but it would have to support a mass 1,000 times greater.

The AT-AT walker also must deal with huge stress on its leg joints, which makes running virtually impossible.

Innovation News Daily: Could America Really Build a "Star Wars" AT-AT Walker?


  1. Sad… same reason 10 foot spiders aren’t very possible. We need better materials or new engineering methods. Or better energy supplies so we can power/move heavier support structures.

    You know I’d always think about this scaling of strength vs mass as a kid. I would fling Matchbox/Hotwheels cars into a solid wall at scale speeds of hundreds of miles per hour, and they would just bounce off unharmed.

    1. Excuse me, but I take exception to your statement about spiders. It is, in fact, not “sad” that we don’t have 10ft tall spiders. That would be terrifying.

    2. You know I’d always think about this scaling of strength vs mass as a kid. I would fling Matchbox/Hotwheels cars into a solid wall at scale speeds of hundreds of miles per hour, and they would just bounce off unharmed.

      For science!

    3. Sad… same reason 10 foot spiders aren’t very possible.

      8 foot spiders are the rule, unless they get hurt.

  2. Well, one assumes that the original AT-ATs were partially supported by some anti-gravity boosters, which that civilisation clearly had, at some desirable power/structural strength engineering trade-off point. The same technology was later used in giant Japanese robots.

  3. Yeah, as I recall, volume increases as the cube of the surface area. Which is why there are no giant insects or 10ft tall humans.

  4. Am I the only one who read the part about AT-AT’s running and had an image of a happy AT-AT prancing through a field of daisies?

  5. It’ll also probably cost another $10 million to let the thing aim at any targets outside the 20 degree cone directly in front of it.

  6. Fun to think about, but unlike the flim a real AT-AT could be taken down ridiculously easily. You only need to take out one leg and then it would crush any support vehicles in its fall path.

    A jet fighter or attack helicopter with AP missiles could probably take out an AT-AT. Heavy artillery would do the business also. Being such a big target doesn’t exactly help matters.

    Now Japanese mecha on the other hand – how about a budget for one of those?

    1. I’ve said it before, but an AT-AT makes a pretty ridiculous troop carrier. Slow and difficult to maneuver, guns only facing one direction, its means of propulsion is its weakest point, and there does not appear to be any way to unload troops easily. The only way it makes sense is if you examine the ideology that may have informed its design. Here is the tool of an Empire that is comfortable, even complacent, in its military and political domination of the galaxy. The AT-AT is more important as a symbol- it towers over the subject peoples of the Empire, the ground shakes when it walks. It moves with a slow inevitability. Like the Death Star, it was built to be so terrifying that no-one would dare to challenge it. Of course, when masters of asymmetrical warfare such as the Alliance actually do challenge it, it proves rather easy to defeat.

    2. this is exactly why I think fan projects like this at some point cross the line into pure silliness. The fact is that an AT-AT is one of the worst military-technology designs one could imagine for use in a heavy weapons environment. Obviously SW is fantasy and not Real Science Fiction so there’s no point in getting all “well that’s dumb” about it *in the context of the movie*….

      but as soon as the question becomes “Could America Really Build a “Star Wars” AT-AT Walker?” the real answer is just “no, because it’s a frickin’ terrible, stupid idea that just looks cool on camera.”

      in terms of “the big list of ludicrous combat mechanics in star wars” – a lengthy list – AT-ATs are up there with hand-guard-less lightsabers; but they’re also almost equally high up the list of “things that look so awesome on screen you’ll never forget it if you see it for the first time before 15 years of age” so there you go.

  7. why didn’t the empire just blow up the rebel base from their starships? This would have had the added bonus of keeping the sucktastic ‘return of the jedi’ from ever being made.

    1. Energy shield protecting the Hoth base from aerial/space strikes, as well as the ion cannon that disabled the orbiting Star Destroyer.

      Duh. :)

      1. they had the technology to blow up entire planets! And when you’re riding around in something called a ‘star destroyer’, well, I think you see where I’m going here.

    2. The AT-ATs were there to take out the shield generator. The movies were better if you paid some attention.

      1. Actually, the movies had quite a few plot-continuity problems like the one I mentioned. So I would contend that they were probably better if you didn’t pay too much attention.

  8. In sheer coolness factor, a static statue of an imperial walker, like that Gundam in Japan, would be nearly as cool as a functional unit.

    One that really walked, would look nothing like the film’s version, because the laws of physics in the Star Wars universe are not the same as ours.

    If you abandon the look of the thing and go for just the functionality, then you would get a much cooler looking war toy that would excel at committing war crimes in urban areas.

    It’s an amusing fanboy fantasy, but it’s not going to attract any competent engineers. They’re busy building something too secret to ever display in public.

    1. I’ll take the robot from Robot Jox. At least they got the movement and speed right for something that’s 10 stories tall.

      Maybe we should focus on things that are a little more realistic to build, you know like Terminators. Judgement day has got to be getting close, better start cracking.

  9. America already HAS a Walker – that destroys everything in its path:

    The governor of Wisconsin.

    Stop America – before it’s TOO LATE!

  10. Weight isn’t necessarily proportional to volume – for a skin-heavy armored system, it’s mostly proportional to surface area, with only some volume dependence for the support structures and lower-density user space inside. So making it 10 times as big means you probably only need 100-200x as strong supports, not 1000x.

  11. “but unlike the flim a real AT-AT could be taken down ridiculously easily”

    Umm… not to be a pedant, but if you go back and watch Ep. 5 (Empire Strikes Back) you’ll notice that they are taken down by what amounts to ropes (OK, super-high-strength cables wrapped around them by fighters, but still…)

  12. The AT-AT is proof that by being evil, the Empire was also becoming inefficient.


    1. The AT-AT is proof that by being evil, the Empire was also becoming inefficient.


      That would explain a lot about the current state of North American nations.

  13. I want a Heavy Gear for myself, one of the few Giant Robots capable of playing hockey! Yeah, us Canadians have plans in place to ensure that we can kick your asses at hockey even if Giant Robots get involved :)

  14. AT-ATs are silly, as many others have pointed out. But the silliness is not just in the Star Wars series; for some reason, big budget Hollywood alien invasion movies usually seem to involve giant, ponderous ships or robots that have to be very close to their targets to do damage (Independence Day, Battle Los Angeles, Transformers, Terminator 4, etc etc). Star-faring species that want to take us out could easily do so by chucking rocks at us. If they wanted to do less damage, they could engineer biological weapons. If they wanted to do precision structural damage, drones are they way to go. Our drones are getting smaller, quicker, and smarter; already they are much more effective than those idiotic ships in Avatar. I don’t understand why hundreds of years in the future, an interstellar military would be so much less competent than it is now. Oh wait– probably an incompetent, rarely used military is a prerequisite for us to reach the stars.

    I know it’s difficult to make movies that withstand a few seconds of critical thinking, but it’d be nice if they tried once in a while. I’m not asking for perfect realism; I’d just like one or two films per year that rub our noses in the stupid.

    /nerd rage

    1. Bab5. Mass drivers dropping rocks on a planet from just outside the gravity well. Sci-fi dun rite.

  15. “A vehicle 10 times the size of a smaller model might have a supporting beam 10 times larger, but it would have to support a mass 1,000 times greater.”

    That’s incorrect. the relation is 100:1,000.

    The supporting beam would still grow in two dimensions (10^2) in regard to its cross section, and that’s what counts in structural calculations.

    And this assumes that the skin is load-bearing and thus grows in thickness.

    1. When I was in college I was part of the group of geeks who built a float for the Rose Parade each year. Every time we had a contest to decide what the next float would be some guy would submit a photo of that damn Volkswagon Spider sculpture and insist that a school with such a strong engineering department should be able to build a functional version of the thing for the parade (and if the walking mech broke down, it could lower itself and drive on its wheels as a failsafe!).

      I was an art major and I still knew enough physics to realize that there was no chance in hell of something like that ever off the ground, but it was kind of flattering that someone thought we could build one if we wanted to.

  16. The solution to this problem is evident in the article itself:

    Tank-like tracks might prove more suitable for a vehicle the size of an AT-AT, Hoffman said.

    That’s right- a JAWA SANDCRAWLER FOR AMERICA. Ideal for swap meets in the Mojave desert.

  17. I don’t care what it costs or the engineering obstacles. We need these before the Chinese get them.

  18. Palm Springs is a treasure trove of giant, crazy, metal, junk sculpture. In a lifetime of pursuing the weird, this Christmas display is in the top five.

  19. I reckon its doable if you change some of the assumptions. For a start make the body and head as light as possible. Put the engines and fuel tanks in the feet where they can rest on the ground. The biggest load will be when one foot is off the ground. Use lots of aluminium and titanium. No armour in the body. The imperial troops were set up to loose anyway.

  20. This might sound stupid, but I always thought they were for low- or no-atmosphere planets or moons, and used on Hoth because it was close to that anyway (yes, I remember the yeti in the cave and that there was clearly oxygen to breathe). They kind of make sense if you imagine that they have to be completely self-contained units to be dropped onto hostile worlds to attack moon bases, mining colonies, etc. Basically, anywhere that wasn’t a real functioning biosphere but that might have your enemy doing something you’d like to put an end to. Dropped out of line of sight on a rocky moon where they ‘walk’ up and attack a base, dropping off troops to take the position once close in sort of thing. In my imagination, most of these places were lower gravity and alter the load somewhat.

    (Yes, I’m aware of the numerous holes in this reasoning. Just saying it made sense when I was 8 and still sort of does).

  21. $100 million or more, huh? Sounds like a fairly small slice out of the US Defence budget to me…

    Hell, not even lightsabres are technically feasible, but that doesn’t stop them from being “cool”.

  22. Yes: neat-o. And, yeah. . .it’s just not a good design.

    Slow as crap, once you get behind one, you’re pretty safe: what is the turning radius of those All Terrain Armored Transports anyway? A quarter of a mile??

    And even IF you built a massive hulking walker, unless beam weapon tech improves, what are you going to do, put a couple of gatling guns in it’s ‘mouth’? Yawn. And for all of the sound and fury; the weaponry was pretty basic. Why not open the side with two score rows of laser gunners like the cannons on a Man-o-War! Turrets on every exposed space! A walking disco ball of burning hot death. . .

    I agree with Boba Fett D.’s breakdown; well played. And a Jawa sand crawler for America?! It’s so terrible it just might work: using solar power it slowly creeps across the southern desert border lands, zapping immigrants and repatriating them: ‘These aren’t the Guatemalans you’re looking for’ -waves hand-

    See?! Awful…

  23. I read most of the responses but not all… Being that I am a Diehard Mecha nerd there is something you are all forgetting. In the Starwars universe weapons were all energy based not projectile based so assuming that the AT-AT needed to have tons and tons of heavy steel armor is false. By looking at the Han Vs Greedo confrontation this proves my theory 100% a Blaster could easily punch a hole through a stormtrooper suit or a metal door But it just made a black spot on the wall of the cantina. At-Ats would most likely be built from the most energy absorbent material available to them and it does not have to be heavy at all, Gypsum or silicon based materials would not be as heavy as steel armor and would protect well against energy weapons. The Belly is constructed from thin lightweight aluminum as proven by Luke being able to slice though it so quickly with his lightsaber compared to how look it took the Jedi to cut thought the armored door in episode 1. Modern memory wire technology is very lightweight and something similar could let the AT-Ats walk.

  24. Just please don’t send them to the many places you wage war… On a second thought those thing would be very easily tripped by insurgent forces, sell the idea to your army.

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