Europe, Russia discuss 'orbital shipyard' plans

On Fri, 22 May 2009 05:20:40 +0000, Derek Lyons wrote:

Fred J. McCall wrote:

(Derek Lyons) wrote:

:Fred J. McCall wrote: :
:Brian Thorn wrote: :
::On Thu, 21 May 2009 03:42:56 GMT, "Alan Erskine"
wrote:
::
:: What you really want to do is... (wait for it) ... build a
manufacturing :: plant on Mars. Once on Mars, you can use Martian
materials, so you don't :: have to bring as much mass up.
::
::Or the Moon - nearer to Earth; no atmosphere at all (compared to
Mars) and ::half the gravity of Mars. Also the Moon's closer to the
Sun, so solar ::energy can be used for smelting materials and
industrial processes. ::
::The two-week nights are the killer. ::
:
:Start at the poles.
:
:Where 13 day nights are the killer.
:

I shouldn't have to explain this, Derek, but...

Get an orange. Shine a light on one side. Go to one of the 'poles'.
Draw a line on the orange perpendicular to the 'terminator' passing
through the 'pole'. Stick in a pin just a bit into the light along that
line. Stick another pin on the same line, just into the dark. Spin the
orange along its 'axis'. Observe just how much time all of BOTH pins
are in the dark.

If you did it right, that time is zero...

I shouldn't have to explain this to you Fred - but the moon isn't a
perfectly aligned orange. Nor are we building bases on pins hundreds of
kilometers above the orange's surface.

D.

Moon has a 1.5 degree tilt to the ecliptic.

The area that can be planted is very small; a thin line, because the moon
rotates, and the light is coming in horizontal, not vertically. So the
first row of plants is going to put the second row of plants in partial
shadow, and the third row in more shadow, and so on. No atmosphere to
create "diffuse" light and all that.

You can plant them on a hill, but the hill will not always be on the
sunny side of the moon, due to the rotation.

Nope. You're going to have to use artificial lighting and lots of man
made energy.