Random Musings from the Warped Minds of Jonathan Goff, Ken Murphy, John Hare, and Kirk Sorensen
Posted in Technology on Apr 1st, 2010
I read an interesting article yesterday on Valterri Maja’s blog (Gravity Loss) about a new class of hydrogen-based materials being researched out at the University of Es sen and a few other locations. Apparently they found a method for lining up the electron spin of the hydrogen atoms in a way that allows [...]
Posted in Lunar Commerce, MHD Aerobraking and TPS, Space Transportation, Technology on Feb 21st, 2010
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 [...]
Posted in Space Tethers, Space Transportation, Technology on Feb 18th, 2010
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tether (tether mass/tip mass) was first done (to the best of my knowledge) by Hans Moravec in an appendix to his unpublished 1978 paper, “Non-Synchronous Orbital Skyhooks for the Moon and Mars with Conventional Materials.”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 [...]
Posted in Space Tethers, Space Transportation, Technology on Feb 17th, 2010
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 [...]
Posted in Space Tethers, Space Transportation, Technology on Feb 16th, 2010
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, [...]
Posted in Launch Vehicles, MHD Aerobraking and TPS, Technology on Feb 14th, 2010
In this installment, I want to dig a lot deeper into the mechanics of how one might maximize the utility of MHD effects for orbital reentry. But first, I wanted to spend a few seconds discussing what is important for an RLV TPS system.
RLV Thermal Protection Systems
Protection from the harsh heating environment caused by [...]
Posted in Launch Vehicles, Lunar Exploration and Development, MHD Aerobraking and TPS, Space Transportation, Technology on Feb 10th, 2010
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 [...]
Posted in Space Tethers, Space Transportation, Technology on Dec 10th, 2009
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. [...]
Posted in Space Tethers, Space Transportation, Technology on Dec 3rd, 2009
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 [...]
Posted in Space Transportation, Technology on Dec 2nd, 2009
Kirk sent me the link to these yesterday, but I didn’t have time to blog them yet. These should hopefully give you a better idea of what we’re talking about. If you have time, the other videos on his youtube channel are pretty interesting as well (though I imagine some of them will be talked [...]