that pack under the shoulders (on the back) is a parachute. When their fuel is low, they climb up and pop the chute for a normal parachute landing.

Those suits will stall at over 70 mph, so there is no way they can land.... unless they want to try landing on a moving vehicle, which HAS been done.

http://www.youtube.com/watch?v=a8Fx_ir6McI