"and vacuum systems" is the key here. The refrigeration is a well-solved issue.

There's impeller-type vacuum engines, which is what most people think about.

Then there's multiple-stage fans, where the purpose is to overcome random atomic vectors: an atom flying the wrong direction is more likely than not to hit a fan blade and bounce vaguely toward the output direction. Extra stages increase the odds of outward vectors, instead of rebounding off walls in some unhelpful direction. These are needed when the pressure is already so low that gas atoms don't hit each other, so they act like particles instead of gases.

There's also molecular getter pumps, that are reactive coatings inside the vacuum. Their purpose is to permanently adhere any stray molecules that tend to cling to surfaces (like H2O), so they won't eventually decouple and ruin the vacuum.

Each is used to reach increasing levels of "vacuum", which is more like "single-molecule denial gates" at that point.