Re: Mechanism for Emergency Ballast jetison.

[John Brownlee <jonnie@chronic.lpl.arizona.edu>]

	Yes, actually magnetic ballast jettison has been used with various
degrees of success by some of the old gasoline float submersibles of the
TRIESTE family. The shot in the hopper was held there by a magnetic field
holding the shot together at the bottom opening. Should the batteries die,
the shot is automatically released. There was a story about when they used
TRIESTE to set the deep diving record that they had to fly in steel shot
with the proper magnetization from Italy, as the domestic shot was not
holding properly in the hoppers. Similar safety devices have been used
throughout since working on this principle, but I don't remember any other
specific examples off the top of my head.
	In terms of holding the weight without electricity on the surface,
that's a mechanisms problem. If you wanted to impliment a magnetic drop,
you would have a locking bar which was put in place on the surface to hold
the weight in with the magnet off. Just remember your 'Remove Before
Flight' ribbons on this one.

							John

John Brownlee
Lunar and Planetary Lab
University of Arizona
jonnie @ lpl . arizona . edu