No, I mean the part that lifts the red tanks into orbit, one one that looks like it only has one engine but it really has two and you have to undock it to separate it. I'll try to find a picture, in any case, Mechjeb works great, it flys them from launch to orbit and rendezvouses with other parts perfectly. Transferring out to Duna is tricky though and I usually have to advance time by about a year before everything is in position. But thats all due to my terrible flying/planning. *edit* That part thats floating off is the part Im talking about. On ships 3 and 4 I have to add a solar panel since the landers themselves are in the caseing and not lasting long enugh to link up with the red tank and it's solar panel, unless I missed something.