Made a nifty under-slung Mun probe, under-slung beneath a manned lander on a 3m fuel tank with a Jr. docking port - shut off the probe brain, so the rocket didn't fly sideways (LESSONS LEARNED!). Landed on the Mun - all was well. Dropped the probe all of half a metre... Forgot to turn on the probe core, so dropped a totally dead probe with no way to control it or turn it on, and too far below the main craft to re-dock it.... REVERT!