That Time NASA Built A Tiny Tank To Pop Shuttle Tires

The Space Shuttle has often been called the most complex pieces of machinery ever built, an underhanded compliment if there ever was one. But it’s a claim not strictly limited to the final spacecraft. With a project as far ahead of the technological curve as the Shuttle was in the 1970s, nearly every component and system of the legendary spaceplane required extensive research and development to realize.

A case in point is that the speed and mass of the Shuttle at touchdown required tires that could survive forces far beyond that of a normal airplane. Pumped up to an incredible 350 psi, the space agency estimated each tire had the explosive potential of two and one-half sticks of dynamite. So while testing landing gear upgrades in the 1990s, they cobbled together an RC tank that could “defuse” a damaged tire remotely by drilling holes into it and letting off the pressure.

The TAV on display at Armstrong Flight Research Center. Credit: DutchSpace

As explained in a recent article on Tank Historia, the CR-990 Tire Assault Vehicle (TAV) was built by NASA contractor [David Carrott] out of a 1/16 scale Tamiya RC Tiger II tank. The toy provided the lower hull and locomotion components, and an upgraded deck and side skirts were fabricated out of metal. In place of the turret, the modified Tiger carried an off-the-shelf DeWalt drill motor with a 3/8-inch bit in the chuck.

There was also a camera and video transmitter which gave the operator a first-person view of the action; an expensive proposition in the 1990s. While the average Hackaday reader could probably rig up their own TAV today for a hundred bucks and the contents of their parts bin, back then, it cost the taxpayers around $3,000. Though to be fair, that was peanuts compared to the six-figure bomb disposal robot that NASA had been using previously.

More than a decade after its retirement, the Space Shuttle is still inspiring future engineers and scientists. While its complexity arguably kept it from hitting many of the program’s original design goals, the iconic winged spacecraft will forever be remembered as one of the most important milestones on humanity’s journey to the stars.

63 thoughts on “That Time NASA Built A Tiny Tank To Pop Shuttle Tires

  1. Seems like a cheap scoped .22 rifle could have done this easier and at less cost. And if a .22 didn’t have enough moxy to make it trhough the tire…well, there are lots of more powerful calibers. BTW, when did “diffuse” replace “defuse” to mean making something safe? Although in this story, you might be able to make a case for “diffuse” being correct…

      1. Yeah I’m with Havoc on this one, I’m usually all about the simplest fix but a piece of foam was enough to damage the heat tiles on those things. God knows what even a .22 ricochet might have done even assuming no one ever missed directly. Also given the pressures it’s resisting I wonder if a larger caliber might be needed to avoid the need for a perfectly placed shot.

        1. To be fair, diffuse in this case seems more technically correct. Defuse is to remove a fuse, but in this case it’s drilling a hole to allow the high pressure air in the tyre to diffuse into the low pressure atmosphere around it.

    1. European here. To be honest, this was my first thought, too. I assumed this would be the most American way to solve a problem. No kidding. From what we’ve learned through media, it’s an united nation under god ‘n’ guns, after all. But then I was sceptical, thinking that no one could possibly be that “tollkühn” (foolhardy?). Then I saw that comment here.. 🙂

        1. We can have guns in Europe, perfectly legally with no major barriers other than basic checks (hell, countries like Switzerland give them out to everyone as part of military service)… we just don’t worship guns or make them a big part of our personal or national identity like some weird cult.

    2. The drill was able to be stopped as soon as the most minor penetration occured, allowing pressure to be realeased as slowly as possible without an explosion occuring. The size of hole made by a bullet is uncontrolled.

    3. “defuse” is correct (as the article has been updated to) if it’s in quotation marks, since it’s used in metaphor with “defuse a bomb”, not in a literal sense. “Diffuse” makes far less sense.

    4. Sure they likely considered it but, probably decided that the risk of a ricochet damaging something important wasn’t worth it. Plus, a drill gives you enough finesse to just cause a slow leak rather than a fracture that rips the tire apart.

  2. $3000 in 1972 is around $22,000 today. That’s peanuts for a robot that performs a critical function. My company spent over $100,000 each for multiple Softbank Pepper robots for research and they’re not capable of drilling a hole in anything.

    1. >> The grim joke at the time was NASA stood for “Need Another Seven Astronauts”.

      I wonder how fast and in how many places that joke originated. I was in a collage class when the news went through the building about the Challenger accident. By the time the class was over and I walked back to the dorm (closest place to find a TV… ah, the 80’s) I’d already heard someone making that comment.

  3. Each shuttle flight they destroyed $33,360 worth of tires. I’m sure this was one of the smaller refurbishment costs per flight, but ouch. What under how much refurbishing a Falcon 9 costs?

    1. Space Shuttle cost $1 Billion per flight. But that includes all the ground support. If launch tempo had increased then that cost would have come down. Still, I doubt it would have be as cheap as the Falcon 9 costs. Best numbers for Falcon 9 are “Less than $67 Million” as that’s the publicly posted price.

      1. That’s a fantasy price that has nothing to do with the actual signed launch prices. For two reasons: the company has to make profit, and they can easily get 2-3x the price out of NASA.

        The rest is just about what numbers you choose to include in the launch cost – what is development cost, what is the actual vehicle cost… I bet even Elon Musk doesn’t know the real number, but he will say anything that suits the marketing. Like, “This car will go 300 miles on a battery and cost $50.000”, when in reality the “and” in that statement was actually XOR.

    1. Yeah…the Buran’s first launch and flight, including landing, was by remote. I would feel much safer in a Russian spacecraft (especially now with Boeing making capsules)…they don’t use their astronauts as guinea pigs. :-)

        1. > I’m hoping that’s sarcasm. How much have you read about the Soviet space program?

          I’ve seen enough to know never to get refueled at a Russian space station without a quick getaway plan :)

    1. Being very familiar with building Tamiya models, I also got the feeling that Tamiya tank is a bit light in the pants. Wonder how long it took to drill through? If it is built like an airplane tyre, then there are at least 3 carcasses to get through…

  4. I like the PRC/DeWalt stickers. Around that time I worked for PRC which was owned by Litton. Litton also owned Black and Decker/DeWalt, so we could get discounts on microwaves and power tools. We got spun off shortly after that, but it was a good deal at the time.

  5. What does this remind me of? Promise not to laugh? Find an episode of the late-Sixties Supermarionation TV series Captain Scarlet and the Mysterons entitled “Winged Assassin”. Actually one of the more suspenseful episodes. No spoilers.

  6. “The Space Shuttle has often been called the most complex pieces of machinery ever built”. I’ve always suspected it was a “jobs” project for STEM folks. As a product, it was exactly what you expect when you try to hire WAY too many skilled people — there just aren’t that many really top-notch ones, so you wind up with a whole lot of mediocre designers. Too many cooks …

    1. I have always found the space shuttle a big abomination. I guess it was mostly praised into heaven to justify it’s cost and to justify other personal agenda’s, but anyone with a reasonable technical back ground should have been able to realize they were trying to make a “reusable” spacecraft at a time that they simply did not have the technology yet to make a reusable spacecraft.

      I guess it’s also politics that decided to put O-rings in an area that should have been a much lighter single piece. Because every village had to be able to make some contribution, instead of making the whole tank in one single on-site factory. But still, quite sad it ended the way it did.

      1. It wouldn’t have been possible to cast the fuel into the solid boosters in one piece. Too much chance of bubbles that would cause problems. Then there was transporting them.

        Far easier to clean out and cast new fuel in segments, and if a casing segment was damaged it could be replaced VS having to scrap an entire one piece rocket casing.

        The issue with having the fuel and casing segmented is the original design didn’t provide enough of an obstacle to hot gas getting to the O rings, and it didn’t have enough O rings in the joints.

        The revised design had more of a “labyrinth seal” that made a longer path hot gas had to move through before reaching the O rings plus an additional O ring was added.

      2. “but anyone with a reasonable technical back ground should have been able to realize they were trying to make a “reusable” spacecraft at a time that they simply did not have the technology yet to make a reusable spacecraft.”

        Making technology that doesn’t exist yet is literally the purpose of NASA, along with inspiring more people to join the science and technology field.

  7. Anyone looked at the first picture, started reading, looked at the second picture, seen the tank tracks closer and got a “wait a minute, thats a Tiger, no, the glacis is angled, is a Panther, but wait again, the glacis is smaller and is has flat wheels, not conical like the Panther’s, it’s a Konig Tiger!” Then continued to read and confirmed it?

  8. Small-scale analogue video transmission wasn’t that big a deal, a VCR emits a weak signal through its coax connection to the TV, and there were regular adverts in the newspapers for cheap (and illegal) video transmitters to beam singals around the house from the VCR in the lounge.

  9. I wonder if they had a pair of round wrenches to tighten that drill bit in the chuck.
    Hand tightened lug nuts, lets go drive on a winding mountain road.
    Even NASA has to use that useless kind of chuck.

  10. You guys realize that this mini-tank was not used (and not intended to be used) on the shuttle? Only on a single test tire, which was fitted on an additional landing gear fitted under a test airplane.

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