So I sent a Kerbal to Duna... But in the planet frenzy of 0.17 I didn't plan any return trip. All I cared about was landing on another planet. Eventually I decided to save him, but the lander was so horribly built that it couldn't fly straight. Now the rescuers also needed to be rescued, so I sent two of these. They worked like a charm and after years and years away from home, they could finally land on Kerbin.