The Moon vs. Mars/Asteroids

Oversimplification in my opinion. Remember that luna has many times
the gravity well that asteroid has.

from http://www.thursdaysclassroom.com/17feb00/article1a.html

"The asteroid is so small ( 21 miles by 8 miles) that a 100 pound
person would only weigh one ounce on Eros."

(0.000625 grav if I've done my math right). 1600oz per 100lb,
1oz/1600 = 0.000625. Luna grav is aprox 1/6 grav, 0.16 (six
repeating). 0.16/0.000625 = 256

This means that an asteroid mission would return over 256 times the
material that a lunar mission would. You would have to launch 256 1
week missions (4.9 years!) to accomplish the same as 1 104 week
mission.
Not to mention the added complexity of refueling your vehicle 256
times, landing it on the lunar surface 256 times and restarting the
engines to launch off of the moon 256 times. Also, how will you power
it durring the lunar night (unless you only land/launch durring lunar
day in which case double the ammount of time for payback).

king_rodent (putting the eek in geek)

> This message is a simple expansion of arguments I have previously
made about
> the Moon being the best first target for mining materials for near
Earth
> space industry (NESI). The Moon's advantages are its proximity, our
> knowledge of the locations of its minerals, and the fact that it
will very
> likely be much easier to convince potential investors that we
really can
> mine there with a high probability of success (so they might
invest). An
> admittedly arbitrary model for comparison is constructed by
assuming a fixed
> rate of return per trip. For the Moon if one assumes a very modest
20%
> profit per trip with 1 week per trip, which in one year, 1.2 raised
to the
> 52 power, gives a return of $ 13,105 for each $ 1 invested. Mars
and
> asteroids, even if one claims a 100% profit per trip requires more
than 2
> years for the first return of $ 1 for each $ 1 invested. By two
years, 104
> weeks, the lunar operations could have returned 1.2 raised to 104,
which is
> $ 171,731,352 per $ 1 invested. I think many investors will feel
they could