Bootstrapping

Hello Tangoman.

This looks like as good a place as any to insert a bookmark. See below
my spiel.

For me, the biggest problem in this project definition is your goal.

If your goal is to build infrastructure you just lost your investors.
They don't want to hear about infrastructure until AFTER they hear about
the profits. Of course, this email group is all about
infrastructure...(GRIN)

Let's take a look at the (strawman?) suggestion you make about 100%
IDENTICAL PARTS. I actually like this idea a LOT! Just leave out the
robots. If we can build 100% identical parts we can also build them
with enough smarts to be able to rendezvous and link up to each other.
I don't care whether that is automatic or telop.

Better yet, why must the "proof of concept" SPS be a single, massive
structure? That is so...1980s.

Put multiple free-flying units into orbit and fly them in formation.
This means lots of redundancy. That's a good thing. This means lots of
control requirements. That's a challenge. Multiple individual units
which become defective can be deorbited and replaced. That's a good
thing. Multiple units make the project relatively scalable. That's a
good thing. Individual units can also be deorbited and replaced over
time with newer, better units. That's a good thing.

Keep in mind that the technologies we will use to create SPS are
currently very much in flux. Radical enhancements to solar photovoltaic
conversion efficiency and radiation hardening may be only a few years
away.

http://www.lbl.gov/Science-Articles/Archive/MSD-full-spectrum-solar-cell
.html

Miniaturization of critical station-keeping ion engine technology and
avionics technology also continue apace.

In my opinion it would be a HUGE step in the right direction to design a
"distributed" SPS made of individually launched modules that fit on
cheap expendable boosters. I would be even happier to see modules so
compact that they could be deployed with Leck Myraibo's laser launcher
but that is probably a generation away.

Don't get hung up on infrastructure. If it is justified by the business
requirements of a profitable venture it will happen. If it is not
justifiable there may still be possibilities for profitable ventures.

Making investors rich by profitably exploiting space resources is the
goal.

Colin Keizer

> Bluntly, can you write a scenario that returns something of >
> physical value to LEO without introducing a single human to space?

I'm sure I could but every scenario that comes to mind meets your
goal but doesn't meet my goal of creating an infrastructure in
orbit. So here goes: use a few hundred russian rockets to launch all
of the components of a SPS into orbit, then have robots asssemble
the 100% IDENTICAL PARTS together. For the non-standard parts, such
as the transmitter array, launch dedictated robots to perform the
integration of that part.

Launch on a single russian rocket a deep space probe to go to a NEO.
Once there, it scoops up ONE cubic meter of frozen methane, and
returns to LEO using atmospheric braking to kill velocity and parks
itself in LEO where we now have to figure out how to retrieve that
Methane and what to do with it. If you're feeling that I'm purposely
stacking the deck here by not sending a complete refinery to the
NEO, making fuel there for its journey back and returning a sizable
cargo of volatiles, well, all I'm doing is looking at the the
payload size of launch vehicles and I'm having trouble imagining
fitting the complexity of a refinary into an existing launch vehicle
or of robotically assembling in orbit such a refinery and vessel.
Frankly, that's where I think humans are necesary.