I remember reading about a very modest escape "system" for the shuttle, which amounted to a pole that could be extended from the side of the body and which the astronauts could "slide" down as they abandoned ship, in order to guide them away from the shuttle wing as they jumped (with a parachute, of course).

Was such a system ever realized?

I imagine you're quite correct Bowser, when you say that Lunar or Mars mission crews would likely understand just exactly how much on-their-own they'd be. Even so, Zubrin addresses the matter of emergencies and the possibilities for rescue in The Case for Mars, and the need to make Mars the second most habitable place in the solar system before astronauts even arrived (ideally).

Still, can you imagine waiting for months or years on Mars for a rescue? There'd probably be no shortage of things to keep them occupied, though. Between science, exploration and survival, I bet their days would be full.