Rs2k

Thanks, that did the trick. It looks like I was using the newest version of Mechjeb which is not compatible.

The ion engines, batteries, and solar pannels do not work in 15.2, how do I get them to work? I\'ve gone back through the earlier posts but it\'s not clear. I have, as far as I know, the latest electrical addon here: http://kerbalspaceprogram.com/forum/index.php?topic=11402.0 and, as far as I know, the latest DSM addon here: http://kerbalspaceprogram.com/forum/index.php?topic=8363.0 Still not working.

Both games are excellent. I love the simplicity and the many combination that KSP allows. I really look forward to seeing the upcoming features list come to be.

I remember playing an old educational game on a Mac over 15 years ago that let you create and launch rockets when I was in grade school. That was the first program that got me interested in programs with realistic physics engines. Over the years I've looked for and found programs that were ok, but I never found anything (that was good) that allowed for launching from a planet with an atmosphere, orbiting, and landing like this program allows for. I really look forward to seeing this game progress. It's a blast.