George William Herbert wrote:
John Schilling wrote:
(garfangle) writes:
Instead of hauling their own fuel for propellent, which adds to its
weight, why not have manned craft launched from massive high-altitude
cannons? Why not further what the late-Gerald Bull envisioned (see
world.std.com/~jlr/doom/bull.htm) to build a supergun that could
launch projectiles large enough to be duplicated as manned capsules?

Because conventional powder guns absolutely cannot accelerate a projectile
to even one-quarter the necessary velocity.

That's not entirely true; there are conventional guns with
muzzle velocities around 3 km/s, which is 1/3 of the way there.

That's still 2/3 of the way not there, though.

Or 8/9ths, depending on how you do the numbers.

--
http://inquisitor.i.am/ | | Ian Stirling.
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"I am the Emperor, and I want dumplings." - Austrian Emperor, Ferdinand I.