Anyone who’s interested in going to the Moon ought to take a serious look at the technology of momentum-exchange tethers. My own interest began back in 1998, when as a summer intern on the X-33 program at Lockheed Martin Skunk Works, I spent time after work trying to come up with a new lunar exploration architecture. My ideas were based on the heavy expectation of ISRU, a heavy-lift rocket, and helium-3 mining at the Moon and later the gas giant Uranus.
After working on the effort for a few weeks, I summoned up the courage to show my ideas to my coworkers. One of them read through my work, and said to me “that’s it? can’t you come up with something better than that?”
I was really crushed and I asked him what he meant. He said, “Don’t you think that after 30 years that we can come up with a better way to go to the Moon than big throwaway rockets?”
Like someone who had just been told that their baby was ugly, I went back to the drawing-board, so to speak, humbled by my colleague’s response to my idea.
I started poking around the internet and found a company called Tethers Unlimited, owned by Robert Hoyt and Robert Forward, the late science fiction writer. This company (TUI) was talking about a kind of space tether I had never heard of before. It spun round and round and caught and threw a payload from one orbit to another. It sounds fantastic (as in fantasy) and I sat there and thought about, fresh from my orbital mechanics course a year earlier. After a few hours I had convinced myself that it didn’t violate the laws of physics or orbital mechanics, and that, in theory, it should be possible to do what they claimed. But I thought it was hopelessly complicated from an engineering perspective. The “catch maneuver” in particular seemed nigh-unto impossible.
Little did I know what I would be getting myself into–some of the most professionally rewarding and frustrating years were to follow that little discovery…
…as a preview, enjoy this animation, which a team of animators and I spent the better part of a year (2004) working on, so that we might make momentum-exchange tether principles easier to understand.