Playing Kerbal Space Program, I wonder why they do several burns to get into orbit. Why can't a vehicle get smoothly to it, just pointing slightly off its course?
I saw a launch at night from 1000 kms from Baikonur, saw the fant vehicle's exhaust. It went with engine on all the time, except for 2nd stage separation, and after a minute of observation, the exhaust disappeared, and it was just a moving star, like other satellites you see in the sky.
I studied the theory of control (not sure how it's called in English), which solves problems like getting to a state and taking into account the trajectory of multiple parameters. A problem like this is solved with a system of differential equations.
So, is such an optimal path smooth, or not? Is this difference just because of low precision of human flying by hand?