Magleving up Chimborazo

> The mass driver would have to be very long, much longer than what is
> proposed here as a first stage substitute.

> If you plan on a human cargo, then the mass driver would have to be
> hundreds, perhaps thousands of kilometres long. You cannot drill
> this distance vertically.

> Alternatively, if you drill down a couple of kilometres, the
> acceleration needed would be hundreds, perhaps thousands of G's.

> If I have time in a few days I could work up a spreadsheet with some
> sample acceleration versus length examples.
From s=at^2 and v=at we get a=v^2/s, where s is distance - in this
case, the length of the mass driver - v is velocity and a is
acceleration. Assume this vertical mass driver must propel its cargo to
12 km/s to overcome air resistance. If the mass driver is 1000 km long,
you get an acceleration of a bit over seven g's.
Seven g's is survivable, but as you say, it is impossible to drill
this distance vertically. Even if you accept ten times that
acceleration (using a water tank and filling even the lungs with
breathable liquid?) and drill from the summit of Mount Everest, you'd
get below the Moho and into the astenosphere. If my memory serves, the
deepest hole that has been drilled is about eleven kilometers, and that
was a narrow hole drilled for scientific purposes, namely to recover
samples.
Alternatively, you could define a maximum acceptable acceleration,
say 10 g (98 m/s^2), rework the equation into s=v^2/a, and get more
than seven hundred kilometers...

Jon L. Beck.