While using electromagnetic effects for atmospheric reentry and thermal protection is interesting, it’s only one of several promising options that have been proposed over the years. There is another application though, where exploiting magnet-hydrodynamic effects could be a much bigger “game changer” — aerobraking and aerocapture for reusable in-space vehicles.
Traditional Aerobraking and Aerocapture
One of the [...]
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Computing the mass ratio for a tapered tether (tether mass/tip mass) was first done (to the best of my knowledge) by Hans Moravec in an appendix to his unpublished 1978 paper, “Non-Synchronous Orbital Skyhooks for the Moon and Mars with Conventional Materials.”
The expression uses the Gaussian error function, erf(x), which is not typically available in [...]
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The history of momentum-exchange tethers goes back many, many years but is bound by a common thread that, until recently, limited the realization of this technology. That common thread is the need for high specific tensile strength.
The first idea of concept of a tether dates back to the imagination of Konstantin Tsiolkovsky, the Russian [...]
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Rotating momentum-exchange tethers are a very exciting technology, but one of my first thoughts after being exposed to the technology was the tricky rendezvous. The space industry has spent all kinds of money and time on satellite rendezvous, and these are typically slow, long, drawn-out affairs with two satellites in almost precisely identical orbits, [...]
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I’ve been meaning to write for a while about a rather fascinating, but not very well known, area of research that I think might have significant implications for several areas of space transportation. The research I am referring to is focused on exploiting Magneto-hydrodynamic forces to manipulate weakly-ionized plasmas caused by hypersonic flight in [...]
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One of the reasons I haven’t blogged much about my reactions to the President’s NASA budget proposal is because I’ve been doing a lot of commenting over at NASASpaceflight.com. I just realized that my latest post could actually serve pretty well as a blog post too, so I’m copying it over here for discussion. One [...]
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The more I think about the Lunar One-Way-to-Stay concept, the more intriguing it is. Fundamentally, it’s one of the only ways with existing transportation systems to get the cost of early lunar experimentation anywhere near low-enough to be useful and interesting. Ultimately, for thriving two-way cislunar commerce, you need tugs, and depots, and [...]
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So I’ve started out telling you that momentum-exchange tethers are great. Why? you might ask. Well, because a spinning momentum-exchange tether is capable of transferring a fair fraction of the orbital energy and angular momentum in its orbit to a payload in just a few minutes. That’s a pretty impressive trick. [...]
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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 [...]
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I want to clean out some of the Skribit suggestions that I’ve been neglecting for a while. Some of these may end up somewhat brief, but I wanted to at least try to be responsive.
Drop Tanks to Enable SSTO?
I don’t like drop tanks. While they do definitely make the rest of the SSTO [...]
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