Existing Commercial Potential for Helium-3 from Luna

>>

>> I would start to set out to the asteroids first and getting back to

>> the Moon later when we are able to support Moon operations with

>>> materials and technology (especially in space construction and

>>fabrication as well as tele-operation) gained at the asteroids.

>

>I would do the opposite. Luanrm ission can be launched quickly,

>asteroids missions take years to accomplish, there are severe launch

>windows liitations for asteroids..

If you dont account for the research and development which has to be done
to support human life and work for month of operations, you are right.
I think, if the same amount of capital given, both developments starting now,
the robotic asteroid prospectors would have brought the first samples back
to Earth years before the human operation even starts.

>> Choosing an Asteroid as close to the Sun as possible would reduce

>> equipment size needed to generate energy from solar panels

>remarkable.

>Yes, if you can find one. Are there any asteroid candidates you

>have in mind?

Some of the athens which can be found at
http://cfa-www.harvard.edu/iau/lists/Atens.html
were p=Perihelion distance (in AU), Q = Aphelion distance (in AU).

2006 US216 p 0.278 Q 0.995 0.04358 19.9 20070410 87.2 55.3 194.4 3.5 0.563 0.637 ( 30d) MPO111369
2006 KZ39 p 0.292 Q 0.939 0.06936 20.2 20070410 123.6 354.0 42.5 9.4 0.525 0.616 ( 2d) MPO102359
2004 XZ130 p 0.337 Q 0.898 0.09449 20.3 20070410 97.8 4.7 211.8 3.0 0.454 0.618 3 E2006-Y44
2006 WE4 p 0.641 Q 0.928 0.10065 18.7 20070410 34.5 318.6 311.1 24.8 0.183 0.785 ( 25d) E2006-Y09

You are right, they are not all the time at perihelion distance to the Sun, but they are at least inside of Earth
orbit when they are at their Aphelion. I guess we will find some more, even smaller asteroids which are inside
Earth orbit.

>Keep in mind that the large delta vee needed to reach

>a near-sol orbit is higher than the delta-vee needed to land on the

>Moon.

I concede that the time period needed to get to the asteroid and back again
is the weak point at this moment of development (there are very interesting developments going
in SEP-propulsion which promise large thrust enhancements).

But delta-V is not the problem, because solar sail propulsion could deliver already unlimited delta-V
while ion-propulsion delivers also much better delta-V than conventional. The long acceleration time
(low thrust) is the problem now.

Frank