Marvin the Martian wrote:

:On Sat, 23 May 2009 12:34:53 -0700, Quadibloc wrote:
:
: Mars is indeed an attractive place to consider building a space colony.
: Its thin - but not virtually nonexistent - atmosphere, though,
: complicates landing on it. And while it has most of the elements needed
: for permanent habitation, nitrogen is in very short supply.
:
:Mars has a 0.6 to 1.0 kPa atmosphere, 2.7% of which is nitrogen.
:Certainly not earth like, but not a lot of nitrogen is needed, and it can
:be "recycled" once gathered from the Martian atmosphere.
:

'Gathered'? You make it sound like you just go out with a basket and
get some. Have you seen the size of the installations that do things
like atmosphere separation of gasses (usually involving cryogenic
distillation)? I have one not far from where I work.

:
:The Martian atmosphere aids, not complicates, landing on the surface of
:Mars. Aero-braking and all that.
:

Sheer ignorance. There's not enough air to help appreciably, but
there's enough (with enough velocity) to complicate landing under
engine power.

--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson