Building a ship in the desert: Just say No to the proposed Earth-

I think that going to L1 before going to the Moon is executing things in
the wrong order.

What would you do at L1 prior to having any lunar surface facilities? You
say
"
If we can get a propellant manufacturing facility up and running on the
Moon, then L1 will be a very popular refueling point.
"

Well, it is perfectly reasonable to build your propellant manufacturing
facility on the Moon first, then build your L1 propellant depot later.

You said
"
We can place a rectenna on the Moon and solar PV arrays at L-1.
"

Well, go put your rectenna in place on the Moon first, and put your solar
PV arrays at L1 later.

You said

"
Lunar surface facilities are expensive,it is very costly in delta-vee to
soft land equipment
on the Moon.
"

That's true, but how else do you propose to get your propellant
manufacturing facility up and running on the Moon? How would you propose
to put a rectenna on the Moon? All of that initial equipment has to be
soft-landed on the Moon.

Ron

charles radley cfrjlr@...
12/12/02 02:40 PM

proposed Earth-Moon L1 station

A station at L1 is the logical next step to developing
the Moon.

I disagree with the argument that we should wait until
we have a plentiful supply of radiation shileding from
luna. The L-1 station can be run with frequent crew
rotations, similar to the ISS.

L-1 is the BEST place to put a solar power satellite
demonstrator. We can place a rectenna on the Moon
and solar PV arrays at L-1. The distance from L-1 to
the Moon is the same as the distance from GEO to
Earth, so it will validate the engineering design
perfectly, and prove that useful power can be beamed
over that distance.

>
> The proposals
> I have seen argue for an L1 station as it can also
> be
> used for launching missions to Mars in the far
> future
> as well as serve as a platform for servicing GEO
> satellites.
>
> Seems like it would be awfully far from GEO for the
> servicing of satellites
> there. (If we were refueling GEO satellites with
> lunar-derived propellants,
> I might could see a case for using Gateway Station
> for that.) As big a

Mike, it has already been done ! A commercial Hughes
Galaxy satellite was inserted into GEO by lunar flyby.
So an L-1 station could indeed have utility in GEO
sevicing missions. If you want to go to GEO from L1
you can most cheaply go via lunar flyby.

Distance is not the issue, the issue is delta-vee.
The difference in delta-vee between a Gesoynchronous
Transfer Orbit (GTO) and a Lunar Transfer Orbit (LTO)
is tiny, a few tens of metres per second IIRC.

And you said yourself, L1 is the perfect place to
refuel a satellite on its way from Earth to GEO.
Getting from Earth to L1 is much cheaper than going
from Earth to GEO. If we fill with lunar propellant
at L1 then it is effectively free passage from there.

> lover of HEO as I am, I think I'd still advocate
> LEO: There would be launch
> windows to a specific GEO slot every hundred minutes
> or so, it would be

The delta-vee from LEO to GEO is very high, that is
the problem.

If we can get a propellant manufacturing facility up
and running on the Moon, then L1 will be a very
popular refueling point.

But saying that we should wait for lunar surface
facilities prior to having an L1 station makes no
sense to me. Lunar surface facilities are expensive,
it is very costly in delta-vee to soft land equipment
on the Moon. By comparison, an L1 station requires
a lot lower investment, it will be a lot easier to get
the funding, and it will get people thinking about the
next step.

It is too much to expect politicians and taxpayers to
make the mental leap from nothing to lunar surface
failities in one jump. An L1 station would be a
relatively inexpensive way to get people thinking in
the right direction.

We will need the L1 station anyway, and it requires
the least up front investment, so let's get started
with it.

Regards,

Charles R.