Eduardo Longoni, a very smart guy I’ve been lucky to work with, was well-known amongst amateur radio operators. When an opportunity came up for them to design and launch an amateur radio relay satellite he was quite excited. I was surprised to find that his main area of interest in that project was heat. I knew heat in space was an issue, but I didn’t quite think it was something to get so excited about.

Perhaps it is thanks to him that I’ve been somewhat careful to explain how pods would deal with heat. After all, any large electrical motor does produce heat, they even have fins to keep them cool. In space, there is no air for a fan to move about. In the space elevator, the electrical motor is part on the pod itself and the other part is the ribbon, were electrical currents are induced, which might warm up dangerously to the point of melting or even burning. After all, any object at such a height above the surface of a planet does have a lot of potential energy and, if you want it to come to rest at the planet surface, all that energy has to go somewhere.

So, that is why I devoted a few sentences to explaining how the heat would be dealt with and how it imposed serious limitations on the speed of the pods.

What I have been not so keen to talk about was about vibration. After all, those long ribbons are like guitar strings ready to be plucked. If vibration gets out of hand, bad things happen, like in the famous Tacoma Narrows bridge, but I admit I don’t know enough to even discuss the subject. My guess is that by carefully spacing the pods, probably not at regular intervals, controlling their acceleration and braking so as not to make stationary waves and adjusting the tension on the cable itself, excessive vibration can be controlled, but I really don’t know that much about that.