The Mass Driver Project

> Hello,
>
> This is my first time posting on a message board, so forgive me if
I
> violate any rules (and tell me what i have done wrong).

Welcome. I went over to your site and was going to leave a message
for you but I suppose you've restricted posting privilges for
guests, therefore this post will have to serve as the vehicle for my
comments.

First off there are a few people from this list who immediately come
to mind when I think of collaborative project management. I'm sure
they'll chime in in due course.

Now, I'm unsure of exactly what your purpose is other than designing
a mass driver. It appears that you want to locate it at the south
pole and launch packets into orbit.

If this is correct, I'd suggest doing some more feasability studies
on the concept itself. First, is there a need for this service.
Payloads launched via mass-driver will have to reach escape velocity
and if all of that velocity is provided by the mass driver you'll be
looking at horrendous accelerations that will restrict the type of
payloads to only a few commondities. Rockets gain most of their
velocity in lateral acceleration through the atmosphere. With a
massdriver all of the KE will have to be imparted at launch.

You also have atmospheric drag issues, heating, sonic booms at the
launch site at ground level unless you're launching through a vacuum
tube and then your sonic issues occur at the interface, if at the
interface then you have synchronization issues at opening the tube
at just the right millisecond to allow the payload to exit but not
flood the tube with atmosphere and impede the acceleration within
the tube, etc.

If the project is simply to design a mass driver, I would suggest
that you look at a lunar mass-driver instead. Any serious effort at
orbital infrastructure development will *never* launch the
construction material from Earth; it will all be sourced from
orbital resources, either the moon or NEOs.

With the moon you would have a lower escape velocity 2.4 km/sec. No
atmosphere. You could launch and deliver the payload to a catcher at
L2. Look to the seminal work by Gerard K. O'Neill "The High
Frontier" and also Tom A. Heppenheimer's "Colonies in Space" for
good introductions to the issues. The books should also give you
good background on ancillary issues.

If the purpose of your project is to deliver material into HEO, then
I would suggest looking at means other than mass drivers, perhaps
tethers. Look to Tethers Unlimited for a series of papers on the
mathematics, physics and orbital details.

Lastly, split the task between your members and work your way
through the archives of this e-mail list and you'll find lots of
detailed discussion on the issues you may be facing with a
massdriver designed to launch payloads from Earth.

Feel free to post your questions to this list. Also, look in the
FILES section for some resources. You have a very ambitious project
and I look forward to reading of your progress.

*Shameless plug* Look here for a first order logistic overview of a
bootstapping process for orbital development.

TangoMan