Crane to Heaven: Tensegrity Catapults

Ken Snelson invented Tensegrity, Bucky stole it or liberated it, promoted it to the World as a engineering technology, a way to do so much "more with less" that everyone on Earth could be provided for in comfort, without "disadvantaging" anyone.

It has still yet to be fully appreciated as a tool for building machines and structures.

For example, Bucky pointed out that the towers built out of compression-only struts and tension-only tendons could serve as compression struts in bigger towers. You can repeat this fractal-wise to make truly colossal structures. They would weigh next to nothing, yet be stable and able to support tonnes.

People have been exploring what is called "actuated" Tensegrity, which basically means controlling the structures you build by changing either the struts, the tendons, or both under computer control. By deforming the tension "quasi-membrane" you can change the geometry of the structure without giving up its strength and resilience.

Take a look at Ken Snelson's "Arch" structure above.

Unlike a normal arch, this one doesn't require support at both ends. You can disconnect one end and the structure would remain standing. You can start from a base and, by selectively lengthening and shortening certain tendons, create a tower that conforms to a wide range of trajectories.

Let's say you build one of these towers. You use elastic tendons, and you allow for a way to "draw" or tighten the tendons to bend the arch, storing the energy in the elastic.

Imagine attaching some weight or load to the end and using the bounciness of the arch to carry it through the air and drop it back down again somewhere else.

Because the arch is basically a spring, you'd be storing energy in it when you lifted rather than expending it . When you put your load back down, you'd get back most of the energy you put into lifting it (neglecting thermodynamic losses.)

So there's a terrific new form of crane, especially when you consider that you can make them as big as Godzilla and they only become more efficient. But wait, there's more.

A reusable non-polluting path to space?

I love space and everything about it. One day I intend to visit it and take a pee-pee. (It both freezes and boils at the same time. In the sunlight? That's gotta be nice!) But rockets, as fun and sexy as they are, tend to be terribly messy, and hard on the air.

(Not all of them. You can use hydrogen peroxide as fuel and react it with a platinum catalyst and it makes a pretty decent, totally non-polluting rocket. The exhaust is steam.)

Well, you know how a bullwhip makes a noise because the tip is going super-sonic at the end of the curl?

Well, I haven't run the numbers, but what if you were to make a giant, say, kilometer long tensegrity "whip"?

You need to reach about 8kps to make it to LEO. Even if you can't get that fast with the catapult, you could still get a huge kinetic head start. Throw your rocketship into the air and then light 'er up!