"Paul F. Dietz" wrote in message ...
The OSP is cast as the latest folly:

http://www.spacedaily.com/news/rocketscience-03zj1.html

In that article it says:
"But surely all the technological advances made since
Dyna-Soar/Shuttle/Hermes will allow OSP to be much
faster/better/cheaper," some of you are saying. Whenever anyone says
this, I demand that they name those technological advances. Nobody
is ever able to, since there haven't been any since about 1964,
when NASA's narrow focus on the Moon Race caused them to stop funding
basic rocketry research.

As a space tether enthusiast, my answer to this is:

1) Spectra-2000 - very high strength cable for tethers
2) Hall Thrusters - can now get enough high ISP thrust to make
reboosting a tether practical
3) The computers and software used for simulation are better now

However, I too am amazed at how little progress there has been
in areas I would expect NASA to do research in. In particular,
I am amazed at the lack of progress in reentry technology. When
looking for papers on transpiration, most of them are from back in
the 1960s. It seems the DOD has ICBMs that use transpiration during
reentry, but details of mass of vehicle, mass of water used, etc
are secret (as far as I can tell anyway). It seems NASA has not
done a single reentry experiment using transpiration.

-- Vince

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Vincent Cate Space Tether Enthusiast
http://spacetethers.com/
Anguilla, East Caribbean http://offshore.ai/vince
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You have to take life as it happens, but you should try to make it
happen the way you want to take it. - German Proverb