Using Sling Shot Power to Hurl Into Orbit
the_2nd_coming writes "space.com has an article
about a new application of a very old technology.
NASA is putting money into Momentum-eXchange/Electrodynamic Reboost tether technology -- MXER for short -- an innovative concept that if implemented would station miles and miles of cart-wheeling cable in orbit around the Earth. Then, rotating like a giant sling, the cable would swoop down and pick up spacecraft in low orbits, then hurl them to higher orbits or even lob them onward to other planets."
The tether system (more at www.tethers.com) decreases its potential energy after propelling the payload. Which is why they suggest a mix of tether technologies, one for the payload transport, and another electro-dyanamic propulsion. Brin wrote a story about the latter.
What is kind of sad is that Dr. Robert Forward was one of the originators of the technology but he never got to see his work in space.
Again, tethers.com explains it all much better than I can.
--foolish