Baby steps to the High Frontier

I promised that I'd post some ideas about bootstrapping HF without
going through the government Mega-Project route, so here goes...

It seems to me that *the* critical issue is markets. Who is going to
buy what, and why are they going to choose extraterrestrial resources
over launch from earth? Most people on this list are probably aware of
Orbital Recovery's plans for a satellite life extension scheme using a
small vehicle that snags the satellite and provides attitude control
after the satellite's onboard ACS fuel is exhausted (the company
homepage is here:http://www.orbitalrecovery.com/>). This seems to me
to hold the possibility of seeding a market for on-orbit refueling. If
the recovery system is designed for refueling it can extend the life of
the satellite still further. Initial deliveries of fuel could be done
using contingency payload capacity on existing launchers. In other
words, if a launcher with a capacity of 5000 lb is launching a 4800 lb
satellite into a convenient orbit (which might be GTO, for example),
you send a 200 lb package along, consisting of basically a bag of ice
(the bag would need to be engineered carefully, but that's no major
obstacle). On orbit you have a retrieval vehicle to pick up the ice and
a processing facility to render it into useful fuel (it might be smart
to send carbon dioxide as well, so you can make fuels other than
hydrogen). The processor is necessarily a high cost item, but retrieval
can be done by something derived from the satellite life extension
vehicle. Now you're in a position where you are generating revenue
(satellite life extension) and you have a market for water and maybe
CO2 in LEO. Once this market is established, the next logical step is
to retrieve volatiles from NEOs. NEO supplies of volatiles can almost
certainly be provided at competitive rates to even contingency payload
supplies. From NEO volatile extraction comes some knowledge of how to
work effectively on resource extraction from NEOs in general, reducing
the risk associated with extraction of platinum group metals from NEOs.
Once PGMs are being extracted the basic infrastructural elements are in
place for building large orbital structures entirely out of ET
resources. This places SPS and orbital colonies within reach.

So far it's nothing more than a story about a possible path forwards.
Obviously there are many variants possible, but I think the outline
above makes the point. If this line of thinking is to be taken
seriously, we have to look at potential pitfalls. The major ones I see
are:
1) the on-orbit fuel processing is a necessity. If fuel and oxidizer
are launched instead of raw materials, the whole bootstrap process
falls apart. I think that launching inert materials is likely to be
looked upon much more favorably than oxidizer or some of the nastier
fuels such as hydrazine. The price demanded by the launch provider will
be lower for inert materials than for materials which might cause the
loss of the whole launcher, but will the price differential be enough
to justify building an orbital processing facility? - I think this is
the biggest "if," one that may kill the whole thing.
2) the whole proposal rests on launch costs remaining above a critical
threshold where dedicated launches of supplies are economically
unattractive. I think there are good reasons to believe that within the
next ten years we will see prices in the neighborhood of $1000/lb to
LEO. The fundamental lowest reasonable launch cost price is probably
about $200/lb (in constant 2003 dollars) to LEO for dedicated launch.
If ET resource extraction is past the teething stage by the time this
floor is reached, there is no problem. If not, it will be hard to
justify the investment needed to start ET resource extraction given the
large risks involved. Perhaps this is an area where government
intervention might be warranted.
3) Market scaling: throughout the discussion above I glossed over
critical problems related to the size of the market. Most importantly,
will the satellite retrieval market ever be big enough to justify the
investment in refueling infrastructure? most likely not. In practice,
once you have the satellite rescue infrastructure in place, people will
start planning for it, launching satellites with only enough of an ACS
to allow capture by a second vehicle with the main ACS and perhaps also
an orbit changing kick engine. There is no question that if satellite
builders could confidently assume that once they got the bird to GTO it
would be taken to GEO by a known trustworthy vehicle, they would design
for that approach. This means there is a LEO/GTO market for fuel. The
orbital tug market might be large enough to justify the investment in
refueling infrastructure, but there are no guarantees.

If the scenario above pans out, then the PGM extraction infrastructure
is well suited to expansion into building large nickel/iron structures
by carbonyl decomposition (see some technical details at
http://www.angelfire.com/co/rwrwrw/carbonyl.htm>).

......Andrew

Dr. Andrew Case, PhD.
Institute for Research in Electronics and Applied Physics,
University of Maryland, College Park
"It is seldom that liberty of any kind is lost all at once."
- David Hume