possible start to asteroid utilization?

Greeting Michael

I to have pondered 'asteroid mining' on a commercial
scale. Where shall I start?

A few year ago in a USC Astronautics class I did a
project and paper on a Solar Thermionic Electric
Generator (STEG) for use at a Lunar Colony on Malapert
Mountain in the southern latitudes of Luna.

After the class I thought of how easily this design
could be converted to Space Solar Power Satellites
(SSPSs). I also took another USC Astronautics course,
Advanced Propulsion, from which I came away from with
a rudimentary design for a Hybrid Solar Powered Rocket
(HSPR).

In high thrust mode it works on Solar Thermal, but in
high efficiency mode it works on Solar Electric. The
engine has a specific impulse of ~3000 sec in the
electric mode, 500 to 1500 sec (adjustable) in the
thermal mode. The working fuel is water, although
some additional degradation of the engine must be
designed away.

Anyway a 15 ton (empty) spaceship, engine tankage,
structure, Solar collectors / STEGs and 2 automated
Service arms plus 30 plus tons of fuel (water) plus a
4 ton Asteroid Tool Kit (ATK) (more on this later).
If the design proved out and was constructed and
tested, the HSPR could be launched on 4 Falcon 9 -
heavys, for $312M (2006) USD. My actual plan is to
launch the HSPRs using a low-cost electromagnetic
launch system (which is the key part of a much bigger
plan that includes Space-Gas-Stations, Automatic
Assembly of small 2 to 20 MW (electric to earth grids)
Space Solar Power Satellites, and a whole lot more),
then assemble and test them in space. However it
would quite probably be worth the effort to launch the
fully tested prototype in this manner as the mission
times are fairly long (3 years minimum, but 5 to 6
years and longer are more typical).

Once the HSPR is checked out and fueled, and at a
precise moment, it accelerates from GTO to a lunar
flyby, and on to a pre-selected Asteroid. There it
will open the ATK, monitor the motion of the asteroid
and determine which, if any large boulders may to
collected for return. The HSPR will land on the
asteroid (or possible a smaller remote walker?) and
collect large boulders, sands and dust and possibly
volitiles (including water) in plastic bags. The ATK
has many large plastic bags, rope/cable, and
transponders to further track the asteroids orbit. It
also has several Laser Spectroscopes and other devices
for chemical analysis. Once the million or so tons of
samples (the Chunk) were collected and bagged, the
HSPR (or the walker?) will wrap a long cable (with a
good anchor and automated release mechanism) several
times around the asteroids equator, attaching the
sample bags and HSPR to the free end. After extensive
earth based calculations are radioed back, the HSPR
blasts off, despinning the asteroid and picking up
several Km/sec Delta-Vee for the trip back toward
earth. The HSPR uses most of it's propellant aiming
itself and the Chunk, into a Lunar flyby resulting in
a 2X Lunar Periodic Orbit. This orbit is quite easily
attained and is very stable.

Once in this orbit, STEG powered machinery will start
to process it. The details have not yet been
completely worked out, indeed they really cannot be
until the asteroidal materials have been analyzed.

If we were fortunate enough by be able to sent 3 HSPRs
out to 3 NEOs, we would like 1st a metallic chunk
(especially heavy in Platinum Group Metals), 2nd an
asteroid or comet nucleus chunk (in a plastic bag)
containing volatiles such as water, methane, CO2,
etc.,
and 3rd, probably more metals, but that's very
tennative at this point. Then each of these 3 HSPRs
would refuel and repeat similar missions, many times.

Anyway once we start processing metal from asteroids
in HEEO, we would use our STEG technology plus MHD
technology to form tanks, pressure vessels, and space
habitats, (with Rad. shielding). Most of these would
be given propulsion systems, and the 100% automated
system would change over to a 99.5% automated system,
with human supervision and enhancement. After humans
live in these colonies, we would probable move these
asteroid recovery operations to earth's L-4 or L-5
zones for safety.

I don't want to discuss costs, time frames, or
technical details. This is just my personal
perception of what may come about. I would very much
like to be a part of this, and indeed I will if I live
long enough.

Dave Handwerk

--- Michael Persohn-Costa wrote: