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."

Comments

This might not be as easy as it seems

[jj_johny]

From an earlier experiment it is clear that there are forces that will wreak havoc on most equipment. Travelling that fast through even the thinnest atmosphere or magnetic field will do some serious stress on things.

Re:Degrading Orbit

[foolish]

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

The Jules Verne Gun

[Jon Abbott]

One similar device is the Jules Verne Gun -- essentially it is a huge cannon that fires things into space, at about 1000 g's. The idea originated from Jules Verne's book From The Earth To The Moon. Popular Mechanics had a write-up about it a few years back (check out the pictures on page 2!) -- apparently some guy at Lawrence Livermore National Labs is trying to build one that actually works. :^)

Re:not a sling shot

[shadowbearer]

Actually, I made and learned to use one for Eagle Scouts (a lot) of years ago. They're not too hard to learn - it's just a matter of timing. Took me maybe 3-4 hours to be able to put a marble into a target about 100 ft away, a few more hours to do so consistently.

They can be devastatingly powerful. I put a small round stone about the size of a marble thru a pickup truck door once :-) Ooops. It didn't penetrate the vinyl interior but left a nice hole in the door metal, and we had to take the truck door apart to get the rock out. My friends' folks were understandably pissed.

What works best for cord is something non-stretchable - makes you aim better - and small diameter, to cut air resistance. As I remember I used carpenters string (used for leveling, strong stuff) and a plastic shot pocket from a wristrocket.

SB