A.W.R. wrote:

Shaped charges using normal explosive via explosions perpendicular not
behind path of travel "fingers on watermellon seed" squirt a molten
bunch of formerly solid materials to 6 - 10 km/s. Not efficient I
think, but maybe benefits make it worth it.


Shaped charges (or, in particular, "retarded shaped charges") are a
standard technique used to simulate orbital debris in laboratory tests.

It is a very effective way to create a spray of 10-12 km/s metal
particles. Do a search on "shaped charge" and "hypervelocity impact"
and you will find lots of examples.


thus maybe squirting molten
metal or even water in solid stream across solar system to wherever
needed? Not an accurate sytem, but moon with its gravity well is big
target, maybe terraform it by dumping 10 meters of water over surface.
Sorry to raise crazy idea, just is a novel and working method of launch
maybe worth exploring.


Fritz Zwiky may have done just that (spray a shaped-charge jet into
solar orbit from atop of an Aerobee sounding rocket) in 1958:

http://utenti.lycos.it/paoloulivi/aerobee.html
http://www.slac.stanford.edu/pubs/be...1-1-maurer.pdf
--
Andrew J. Higgins Mechanical Engineering Dept.
Associate Professor McGill University
Shock Wave Physics Group Montreal, Quebec CANADA
http://www.mcgill.ca/mecheng/staff/academic/higgins/