The Mass Driver Project

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

Thank you for your response. I looked at your extensive work on
orbital development. Very interesting.

> 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.

Very shortly I'll have the privileges changed so guests can post
comments. I will notify you here when the change is made.

If you would like your own personal login with full privileges
please contact me (dgerl@...

> Now, I'm unsure of exactly what your purpose is other than
> designing a mass driver.

This project has two purposes:

1) Evaluate the effectiveness of open source principles to develop a
feasible physical system design. As the project proceeds new
methods or software tools may be introduced to make the
collaboration process easier.

2) Develop a feasibility study and conceptual design of a mass
driver system capable of delivering material from the Earth surface
to Earth orbit. A mass driver was chosen as the physical system to
be developed using open source principles because it is an
interesting, complex problem that would have minimal potential
intellectual property disputes.

The initial concept system that I am trying to analyze for
feasibility is as follows.

1. The launcher mechanism is located on (or near) the Earth
surface; it will launch a series of material pellets as a stream.
The launch technology used must be capable of a rapid launch rate.

2. The material pellets are to be relatively small, to keep the
launch energies low (probably below 1 kg total mass). The material
pellets may be a layered construction; a heat resistant material
encases more sensitive material like water and fuel.
*The idea is the first few material pellets of the material stream
will be sacrificed to "cut" through the atmosphere. A rapid launch
rate will allow the material pellet stream to travel through
essentially a "hole" in the atmosphere. I.E. the first few pellets
rarify the atmosphere by burning and pushing the atmosphere out of
the way.
*It also has been suggested that the atmosphere may also be rarified
by ionizing it with a laser.
*It is hoped that the construction of the material pellet can be
very simple and therefore cheap. It is intended that the pellet
remain 'dumb'; i.e. no guidance, telemetry or propulsion systems.

3. A 'catcher' satellite, located in geo-synchronous orbit,
captures the material pellets. This satellite uses the material
pellets or distributes to other satellites.

*GEO was selected because it simplifies the design of the launcher,
since with respect to the launcher the 'catcher' satellite will be
stationary. The launcher will not have to be aimed at a moving
target in the sky.
*The velocity difference between the orbiting 'catcher' satellite
and the material pellet will have to be minimized to simplify
the 'catcher' satellite design.

These are the big boxes that will be defined as the project proceeds.

Note: The concept system is not set in stone. Please consider it
as iteration ONE. It is intended the concept will evolve as
problems are discovered and resolved.

Any ideas, suggestions, references and volunteered time will be
appreciated.

--- In ssi_list@... "victoriatangoman"
> > 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