One argument against the initial use of NEOs as sources of extraterrestrial
resources is the long flight times to and from the NEO, and their impact on
cash flow. Let us examine the flight time issue versus the usage of Lunar
materials. Consider the following scenarios for the usage of
extraterrestrial resources in the manufacture of a Solar Power Satellite
(SPS):

NEO SPS Scenario: Tools, robots, humans, etc. are shipped to a NEO. An
SPS is assembled there from local materials, and later flown back to GEO
using electrical propulsion.

HEO/Luna SPS Scenario: Materials are mined from the Moon and transported
to a space manufacturing facility (SMF) in high-Earth orbit (HEO). The
SPS is manufactured at the SMF and later transported to GEO.

NEO/HEO SPS Scenario: Mining and transport equipment is shipped to a NEO.
Raw materials are shipped back to an SMF in HEO, where an SPS is
constructed and later shipped to GEO.

In the NEO Scenario, the SMF goes to where the resources are. This
scenario incurs long flight times relative to the HEO Scenario.
In the HEO Scenario, the resources go to where the SMF is. This scenario
incurs long infrastructure development times relative to the NEO Scenario.

(I'll let Charles and Mike compare/contrast the NEO/HEO Scenario if they
wish, as that one was their idea.)

It is noteworthy that in the HEO/Luna Scenario, the resources do not
instantaneously appear at the SMF. Rather, an infrastructure must be
established to transport materials from the Lunar surface to the SMF.
This infrastructure might be, for example, a mass driver/catcher system, or
it might constitute some Lunar production of oxygen, aluminum, or other
materials in a chemical propulsion scenario. After this infrastructure is
constructed, then it must operate for some time to allow mass to accumulate
at the SMF.

So, a question of interest when comparing the NEO Scenario to the HEO/Luna
Scenario is how long, relative to the flight times to the NEO, does the
development and operation of the Lunar infrastructure take? Perhaps it
takes 180 days for the workers and equipment to get from Earth to the NEO,
but is it the case that the required Lunar infrastructure in the HEO/Luna
Scenario would be fully developed in less than 180 days? I think when we
consider this, any perceived time difference between the NEO Scenario and
the HEO/Luna Scenario either disappears or becomes far less important than
it would seem at first glance.

Ron Menich

>

>
> So, a question of interest when comparing the NEO Scenario to the HEO/Luna
> Scenario is how long, relative to the flight times to the NEO, does the
> development and operation of the Lunar infrastructure take? Perhaps it
> takes 180 days for the workers and equipment to get from Earth to the NEO,
> but is it the case that the required Lunar infrastructure in the HEO/Luna
> Scenario would be fully developed in less than 180 days? I think when we
> consider this, any perceived time difference between the NEO Scenario and
> the HEO/Luna Scenario either disappears or becomes far less important than
> it would seem at first glance.
>

Not much.

The time value cost of debt service was only one of a couple of factors,
you did not address the others.

A biggie is the problem of how to supply spare parts to a NEO facility,
or the cost of taking a large supply of spare parts along at the start.
This is a killer for manned Mars missions, for example.

> One argument against the initial use of NEOs as sources of extraterrestrial
> resources is the long flight times to and from the NEO, and their impact on
>

> Scenario would be fully developed in less than 180 days? I think when we
> consider this, any perceived time difference between the NEO Scenario and
> the HEO/Luna Scenario either disappears or becomes far less important than
> it would seem at first glance.
>

180 days of debt service on, say, US$10billion is a good chunk of change. It would be prominent in at least two quarterly shareholder reports.

============

Sending a manned vehicle such as ISS to a NEO has all the same problems as a manned mission to Mars. What if a crewmember falls sick ? OR what about an Apoll-13 type scenario (critical failure in the life support system). These types of problems lead us to look at what type of abort scenarios are avaialble. IT effectively killed the 1989 Space Exploraiton Initiatve,
the astronaut office demanded safe abort mode for any point of the mission. This meant nuclear propulsion, chemical would not suffice.

Developing nuclear rockets is a political hot potate, nobody wanted to touch that one. And of course very high development cost.

For a NEO mission I would recommend designing a mission which is 100% robotic and/or teleoperated.

cfrjlr (Charles?) wrote,

"For a NEO mission I would recommend designing a mission which is 100%
robotic and/or teleoperated."

I agree that the number of human crew/workers should be minimized in ANY
space resource utilization scenario, be that a NEO scenario, or a Lunar
one, or a NEO/HEO one, or a Lunar/HEO one. As time goes on and more and
more Moore's Law cycles pass, our ability to use robotics/teleoperation
will increase steadily, and our need for people onsite will lessen.

But I'm not confident that any of these scenarios would be successful today
without at least some onsite human workers to debug unforeseen glitches.

Ron Menich

cfrjlr (Charles?) wrote,

"180 days of debt service on, say, US$10billion is a good chunk of change.
It would be prominent in at least two quarterly shareholder reports."

True. But developing the necessary infrastructure to deliver the first
thousand tons of raw material from the Lunar surface to a HEO manufacturing
facility is a big step, one that might take 180 days, a year, or probably
even longer to develop.

By contrast, delivering the first thousand tons of raw material from a NEO
to a facility located a few kilometers away would be relatively trivial
once the facility has arrived at the NEO. It could probably be done in a
few days.

Ron Menich

cfrjlr@...
Please respond HEO/Lunar scenarios
to ssi_list

In a message dated Mon, 30 Jul 2001 1:38:11 PM Eastern Daylight Time,
rmenich@... writes:

> One argument against the initial use of NEOs as sources of
extraterrestrial
> resources is the long flight times to and from the NEO, and their impact
on
>

> Scenario would be fully developed in less than 180 days? I think when we
> consider this, any perceived time difference between the NEO Scenario and
> the HEO/Luna Scenario either disappears or becomes far less important
than
> it would seem at first glance.
>

180 days of debt service on, say, US$10billion is a good chunk of change.
It would be prominent in at least two quarterly shareholder reports.

>
> cfrjlr (Charles?) wrote,
>

Yes, this is Charles F. Radley, also foujnd as cfrjlr@...

only messages, whereas AOL does not, everything AOL 6.0 sends out is
html, which is considered impolite and indeed dangerous on public lists
(there are some rather unpleasant security issues with html).

For my personal correspondence I prefer the aol account.

> more Moore's Law cycles pass, our ability to use robotics/teleoperation
> will increase steadily, and our need for people onsite will lessen.
>
> But I'm not confident that any of these scenarios would be successful today
> without at least some onsite human workers to debug unforeseen glitches.
>

Yes. I have found myself on both sides of this debate (human versus
robotoic).

I posted some thoughts on this subject to the innertransit.net website
under SOFA.