MGM

Oh, I commented on that in another post: http://forum.kerbalspaceprogram.com/threads/104700-What-s-the-point-of-the-first-step-of-re-root-tool/page2 The two-step does work on subassemblies, but you have to have the subassembly selected so you're dragging it around when you click on the root tool.

For what it's worth, I use the root tool constantly to manipulate ghosted sub assemblies. It's simple. I might attach something axially below my rocket to set up symmetry on it, then pull it off to attach it radially. All you have to do is pick up the sub assembly, put it down, pick it up again and position your camera so the instant you click on the root tool button, your sub assembly gets placed somewhere reasonable that it isn't accidentally attached to your rocket. Then you pick the current root part of the subassembly - the part that makes the whole subassembly light up, then for step 2, you chose the part you want to attach the subassembly by. I've been thinking about making a video demonstrating that. It's clearly buggy that it only works that way.

Whoa! Terrific answers. Awesome information! Kudos to mhoram for the link to the perfect answer with all the info I needed that happens to cite "page 65 of the 1993 edition of Prussing and Conway's Orbital Mechanics textbook." I would love to have that on my shelf! Bigger kudos to maltesh for the plot demonstrating that the furthest distance traveled is actually at 25 degrees. Math win! Biggest kudos to Gaarst for accidentally guessing the correct answer, lol. Jeb would be proud! Thanks guys! I'm probably about to mark this as answered, but I want to play with that desmos plot a bit. It gives you the optimum angle for greatest distance given a velocity. I'm looking for angle with the lowest launch velocity given a travel distance. Thanks for the science/math, all! [EDIT] I did play with the graph a bit. The velocity I'm looking for is about 154m/s at about 44 degrees. Cool tool, maltesh!

Thanks! Intuitively, I suspected this. Why 45 degrees? Maybe I should math that. I've had multiple instances where I'd like to have the ability to target a spot on the ground from map view. But I think if I try your method, I can mostly do it with what I have. Incidentally, I tested in orbit and found my mini-hopper does have 2300 delta-V. The calculations were correct. The fact that I spent all of it on two 15km trips, two landings, and one shabbily executed surface docking operation is alarming.

My Mun base lander has a mini lander/hopper that is powered by RCS thrust. Vernor engines, actually. I want to hop around and gather science in different biomes without wasting too much fuel. There are 4 biomes within a small distance of the initial landing site. My intuition is that the most efficient way to get from point a to point b in the absence of atmosphere is a single launch burn, creating a suborbital trajectory, then a suicide burn. And... I guess you also need to figure out the optimal launch angle. I wouldn't be able to figure out any of that without knowing the distance between point and a and b... kerbalmaps gets me a rough estimate that I'm going about 15km each way. I'm sure I'm overthinking this. What I'm doing right now is pointing in the general direction I want to go, thrusting at 45 degrees until I have a little elevation and vertical speed, switch to map view, zoom in on my tiny orbit, and thrust toward the horizon until it looks like I'm headed to my landing zone, and get my horizontal velocity around 60m/s. From that point out, I point skyward and keep my vertical speed close to zero until it's time to land. But it's pretty clear that the lower my horizontal speed is, the more dV I'm going to waste fighting gravity, but the faster it is, the more dV I spend starting and stopping. Even if this is somewhat inefficient, I have fuel to burn, literally. In theory, according to my last calculation, my vernor-hopper has about 2k dV. But after flying 15 kilometers, landing, flying back, landing again, way more than half of my dV is gone. So... my calculation is wrong or I'm wasting a ton of fuel. It still takes me quite a bit of fuel to properly dock the hopper on top of the base for refueling. Any tips? Side note: I would love the ability to plan a maneuver node on the ground. Like... ballistic maneuver node, lol.