Docking Rings

[Irioth]

What exactly do docking rings do? Every planet in Sirius that has human life on it has one. The fact that they exist implies that a ship, by itself, isn't able to dock with a planet. So, what does the docking ring do to allow these ships to reach the surface safely?

I've only been able to think of a few things, and I might even start a poll soon once I get a feel for the popular answers. One idea is that it's like a space elevator, so it just carries smaller ships down to the surface. They could also slow the descent of ships so the heat of reentry isn't a huge deal, but I don't know how they'd do it.

Another thing to keep in mind is that the models of most fighter/bomber class ships aren't aerodynamic. Take the Turanic fighter for example. In an atmosphere, that thing would fly about as well as the rocks outside my house. Sure, it has an engine, but it certainly doesn't generate any other lift in any way similar to modern aircraft, so that would have to be a crazy-powerful engine. Granted, I don't study aerodynamics. so my thoughts on this may be off.

I'd just like some thoughts about this. I know Freelancer isn't the most realistic of games, but some pseudo-reasonable explanation about docking rings would be cool. Thanks.