Erm... while we're discussing science and logic... tradelanes? nomads? mass-less armour upgrades? the engines themselves? the physics?
Seriously, Freelancer isn't meant to be scientifically sound, it wouldn't work if it was.
However, if we must discuss it, the docking rings' elevator doesn't go all the way to the planet, infact probably only slows down/assists in speeding up a ship through the outer atmosphere, once it's slowed down enough it can detach and fly to the ground under it's own propulsion. Then it takes off under it's own power, flys upwards til it needs some assistance, docks with the elevator.
It works fine, Ageira's developed many things which don't make sense by our logic, but they're basing it from Daam'K'vosh material, an 'advanced race'. So they came up with some impossible magical stuff.