Playing Lunar Catch

On 19/05/2009, Combs, Mike wrote:
> I would envision the catching mass-driver as having a kind of "bugle flare"
> at the entry end. If the mass-driver is in "pull-only" mode, there's a
> strong centering force on the bucket. One might have to design some way of
> dampening out oscillations, though.

If you have a 0.3m/s wobble, over a 6 minute flight you would miss the
centre of the catcher by about 100m. That's a heck of a bugle. And
longer flights require proportionately greater damping and accuracy
and an even bigger bugle.

I suppose in theory you could use rockets to do mid-course
corrections, but it's not exactly overwhelming me with confidence;
miss the catcher and it's all-she-wrote. Also if the thrower
underperforms and lobs more than slightly short then you're toast.
Really scary for anyone travelling on it; might work for cargo. Then
there's the g-forces- people would be squashed flat.

> Mike Combs

--
-Ian Woollard

"All the world's a stage... but you'll grow out of it eventually."