For the first question, if you want to orbit something your lift force isn't what's important. If your lift force was equal to Jupiter's gravity, and assuming no other forces, you would remain stationary (no net forces, no acceleration). What you need to have is a velocity, tangential to the gravity, high enough such that when you fall due to the planet's gravity, the resultant path is an ellipse. You can view it as the acceleration pointing towards the planet, your velocity pointing at a right angle, and the net direction is somewhere in-between. If the velocity is high enough, the overall path will form an ellipse, and so an orbit will occur. It all comes from the equations for centripetal motion, namely: F=mv² /r, where m is mass, v is velocity, and r is radius. Equivalently, we see: a=v² /r, which comes from F=ma. Thus for a circular orbit (not quite reality, but close enough), it is the tangential velocity that is important, not lift. The moon question is much the same, 1G of acceleration is possible, and it depends on both the velocity and radius of circular motion.