posted on Nov, 13 2012 @ 03:18 PM
There are a few things you need to understand about ultra high vacuum before you can even attempt such a thing.
Firstly, space is very empty between the stars, back during my astronomy course I was informed that, in a very dense cloud you might get 1-50atoms per
cubic meter... which is you might agree is not very much.
With modest equipment on Earth you can generate a vacuum of 10^-10mbar using a turbo molecular pump. At room temperature, that pressure equates about
2.41x10^12 atoms per cubic meter which is ALOT higher than 1-50 atoms.
Now the other misconception is that at those pressures, you dont suck the atoms out, instead you sweep them. As the atoms/molecules move around
(roughly in straight lines at those pressures) they will hit the walls of the chamber and bounce off (or stick, but lets assume they bounce for now)
until they hit the blades of the turbo pump. The turbo literally knocks the molecules into the lower stages of turbo until they are then removed from
the system by a backing pump.
So the classic idea of migration of high density to low density is not strictly adhered to at ultra high vacuum since the path length between
interacting molecules is larger than the size of the chamber and the density is too low.
So if you was to go out there with a super amazing vacuum... you need to open the camber, wait for a while, collect your handful of atoms and then
close the chamber making sure you seal it well enough that nothing can get in. For those who haven't worked with ultra high vacuum, it basically
involves a copper or other metal gasket and a knife edge seal. It is not something that is trivial to do in an automated manner.
So basically what you propose is amazingly difficult to achieve in reality. The best vacuum ever achieved is somewhere around 1x10-13mbar which is
still about 3x9 atoms per cubic meter.
The basic difficulty is cleaning the materials, surface finish of the chamber and then pulling all the molecules out. You might think steel doesn't
absorb anything, but when you have worked with ultra-high vacuum you start to realize that steel actually does hold onto molecules in the air. I spent
the last 3 years working with such systems and once you have a system clean and down to a good 10-8 mbar level vacuum, you dont want to open it up,
because the moment you do, any humidity in the air causes water to stick to the steel and you then spend about 3 weeks pumping the damn thing out
again to get it back to 10^-8.
The method that would be more useful i think would be a cryopump, which is when you get a device to generate kelvin scale temperatures, an object like
this can 'freeze' out molecules that hit it, and so you could just collect molecules on that. BUT... since alot of gas out in space is simply
hydrogen and helium, you are not going to simply be able to freeze it out, the freezing temperatures themselves for this is very low also.