Hypothetical

Earlier in the week, I got Jeb into orbit around Duna, only to find that I had mismounted the SAS module, and it was keeping the landing stage from developing thrust. So... I made a duplicate with a Stayputnik for remote control, and sent it up. Rendezvoused the remote control lander with the main one, and then used KAS pipe ports to top off the fuel in the lander, and EVA'd my pilots over. Landed, did some science, retrieved the data, dumped the science modules, and relaunched. Caught up with the bad lander, transferred remaining fuel to the manned lander, and successfully made it back to Kerbin! First Duna landing! Here are the two landers in orbit around Duna, prior to landing. The bad lander has a KLAW because I had originally intended to grab the middle stage with it to hold it steady while transferring fuel.

I built my first Duna lander, flew it to the planet, started my deorbit burn... Um. Jeb, start deorbit burn. Start the burn, Jeb. Engine is on.. why u not slow down? Turns out that if you mount the large ASAS ring *above* the decoupler, the engine fairing on your current stage doesn't disappear and the thrust can't reach space. Now it's time for a Duna orbit rescue mission!