Third Time's the Charm: Another Swing at a Modded Career in Mission Reports Posted February 19, 2018 19 hours ago, Geschosskopf said: I dunno. Windows to OPM planets come at intervals of 1 year plus a few days. At timescales of 1 year, OPM planets don't move very much so it's all about Kerbin making a lap. Also, because OPM planets don't move very fast, their inclinations and eccentricities make only small, incremental dV differences from one window to the next---it takes many years before such effects add up to anything significant, if they ever do (really only matters for Plock). So don't sweat launching for OPM at the earliest opportunity. You'll get another chance every year. Leaving 3-5 years into the game makes no real difference to the trip itself but lets you have much higher tech, perhaps even with the tech tree complete. You really want to have the tech tree complete before you leave. First, you want the tech for the OPM trip itself. Second, the trips take so long that you'll have the tech tree finished before the OPM mission arrives, so you effectively get no Science! from out there anyway. Third if you still have to scrounge Science! closer in while your OPM misison is en route, your OPM mission won't make noticeable progress. The only way to ever see the Outer Planets is to warp ahead for years at a time while doing nothing else. Y'know on some level, I'm sure I knew launch windows come up once a Kerbin year, it seems so obvious now that I think about it... I guess I was just stuck on thinking in month time-frames. There'll definitely be a mission to recover the original Herkel for kicks once I've got some shinier toys to do it.