SPS

>>>>>>>>>>>>>>>>
> Before anybody gets too excited, the source I read said "by 2040".
> Yes, unlike here in the states, the Japanese really do try to plan
> that far ahead.
> >>>>>>>>>>>>>>>
> >>
>
> I hate to sound critical but...
> Saying that their going to build an SPS by 2040 is an empty boast. The US
> Government could say a similar thing at no cost to the present and for all
we
> know we could be right to. By pushing such a goal so far in the future they
> are passing on the obligation of implementing it to their descendents, It
> really is a cheap bit of rhetoric. When were ready to finally build an SPS
we
> should be able to build one in 10 years or less.
>
> Tom Kalbfus
> >>

Can't be more true. ( Sorry for the late answer)
I think a real project would include a path to the SPS, something as:

1/ Build back the Saturn V or Energya launcher.
2/Use the first flights to launch a ion engine powered tether.
3/Use that leo tether to boost the mass launched to 250 metric tons.
4/ Use that new capacity to launch a LEO to GTO and a LEO to LTO tethers.
5/Put an lunar orbit to Moon ground and ground to orbit tether.
6/ Build a LEO material processing facility. (May be tested on ISS).
7/Import raw material from the Moon to LEO and process them into SPS
structures.
8/ Launch solar cells from Earth in 250 t batches with the tether assisted
Saturn-like launcher.

The first steps in that direction would be:
A/ Test a processing facility on ISS.
B/ Test a big tether system in space.
C/ Test a large ion or plasma engine in space.

I see nothing of that, so I think everything about SPS is mere political
discourse with no content.

Yvan Bozzonetti.