Mass drivers as spaceship launchers

>
> I think you are oversimplifying the space tower to make it sound
easy
> to build. Even assuming that carbon nanotube caould be built in
> suffucient quantities, the tower would have to be much more massive
> than you believe. The tower has to support its own wieght, the
weight
> of everything you hang on it (I'll get back to that point) and the
> forces associated with the motion of things up and down it.

Yes, an 800 thousand ton elevator to lift 20 ton cargos. Bear in
mind that the elevator is a ribbon about a meter wide and only a few
microns thick at the earths surface, tapering up to a meter by a few
millimeters at GEO.

>
> The minimum stuff you need on the tower is an electrical grid 36
000
> km long. Power to run everything has to come from somewhere and
has to
> be available where it is required. After that you probably want a
> couple of way stations along the way.

Power would be beamed to the climbers.

>Assuming a maximum speed of the
> 1000 km/hr, which is probably way to high for a vehicle that needs
to
> be attached to the tower (even magnetically attached), the vehicle
> will take 36 hrs to get to its destination. I don't think there are
> many flights that are that long. Also the way stations are needed
for
> scheduling low speed freight vs high speed passenger vehicles.

Nothing would be going at high speeds on an SE. The estimated
length of a trip to GEO is one week.

Finally
> a way station is probably a great place a tourist resort.

Probably the best way to do this is to leave the SE bare, and have a
space station orbiting in GEO a few tens of kilometers ahead of or
behind the SE.

>
> Now, let us look at the 'first stage' coil gun. This is a great
idea.
> The perfect place for such a launch facility is Ecaudor and Peru.
Both
> have extensive high mountain ranges on the equator.

I was thinking of that area, perhaps Venezuela.

> Also if you could
> start in the tibetan plateau and build a glorified pyramid another
10
> km up using existing earth moving techniques as well.

That won't happen. It would collapse under its own weight. No
materials have the compressive strength to hold up a structure that
extends 10 km above sea level.

>There is no
> physical region why a pyramid that pops up above the atmosphere
> couldn't be built using existing mining and building techniques.
Once
> above 90% of the atmosphere, the muzzle speed of this coilgun
could be
> orbital velocity or close too it.
>
> Bill

Fortunately, one does not need to have an assist from a coilgun to
escape velocity or orbital velocity; an assist to say Mach 0.7 at
12000 feet is an enormous savings in fuel that must be carried by
the craft.

Ed