This is excellent! Options files are a great way for people to quickly tweak the numbers to fit their preferences. However, the algorithms need more fundamental adjustments. For example, the old method considers a solar orbit near Eve or Duna easier than an orbit near Kerbin. We need a more nuanced method to figure out difficulty of missions based on the celestial body we're looking at. The old code multiplies difficulty by sphere of influence to get maximum altitude for random sat missions. This is very simple to write, so I understand why you used it, just to get something in there and working. I spent a few hours thinking of ways we can improve it. I divided solar orbits into three regions: near Kerbin (low ÃŽâ€v), far from the sun (medium), and close to the sun (high, on average). In addition, high orbits near non-Kerbin planets are easier than low orbits, so I inverted the difficulty-to-altitude relationship for planetary bodies other than Kerbin. I also used the high/low space boundary to split orbits into thirds, instead of difficulty*SOI. The SOI doesn't have a regular relationship to the ∆v required to reach orbits around that body. It's irregular because KSP uses simple one-body gravitational interactions. They had to set the SOI to values that are good for escape/capture, but don't match orbits well. This is why they set the hi/low science orbit boundary by hand for each planet and moon. The science boundary is a better indicator of difficulty for various orbits around a body. For aerial and rover missions on Kerbin, consider centering them somewhere close to the space center, but not quite on it. We play the game to have fun, flying should be enjoyable, and the terrain around the space center is rather boring. It's mostly featureless flat land and water. I centered these missions around interesting landscape features to give people a nice view while completing the mission. Introductory flights go around the old-airfield islands to the southeast, and mountains to the west. Rover missions go around the space center at first, then the hills to the southwest. It's fun to explore these areas. Something else to consider is adding more distance or waypoints for missions on Kerbin doesn't really make them harder, it just makes them take longer, which isn't very fun. The altitude range is a more important factor for aerial flight difficulty. Flying at low altitudes is easy because low speeds and high air density give us good control over aircraft. The descriptions for some missions make sense for other planets, but are odd for Kerbin. Why would the space center be a place we don't know much about? I rephrased Kerbin aerial missions to evoke the experimental test plane projects of history: Old: "There are places on Kerbin that we don't know much about, fly over them and see what you can see." New: "Pilot a jet to these locations to collect test flight data for commercial aircraft engineering."