CodaThePortalmaster

There is DarkMultiPlayer, which adds multiplayer support for ksp, although two different vehicles controlled by two people that close to each other tend to bug out.

No matter how hard I try I just can't figure out how to calculate Delta-V. Can someone explain it then give an example{and please don't just link me to thewjkrh(or whatever) rocket equation on wikipedia.} Thanks to Zhetaan for helping me understand.

I don't know why your trying to do it going prograde... anyways, just launch BACKWARDS from the KSC and once your in orbit burn retrograde at your farthest point from the sun until you achieve escape velocity, should be cheaper in delta v to do this too.

ISP doesn't decrease as you go down, but the terrain does start getting a bit sketchy(atleast for me) under 1050m. Ore tanks might be good to and just slap engines on the back but I use subs kinda like obi's, without mods of course.

I do that all the time, I just grab the data and pull a Yuri Gagarin