Orac is bringing up some questions that plague actual launches where the aim is to get into a particular orbit. The general idea of escape velocity includes a number of simplifying assumptions. Your idea also contains a number of simplifying assumptions. You have addressed some of them such as only going vertical. In one of your later ones you actually mention some other problems such as air drag. But for the simple solution that you have discussed those are mostly ignorable. Just getting away from the Earth can be done as you say, with a very small acceleration, as long as it is greater than the Earth's gravitational attraction, which of course does vary with height. A small acceleration maintained over a long period of time is just as good as a large acceleration for a short period of time. In a real world situation where somebody is trying to launch something such as a satellite that won't work very well. There is no good way to achieve the very low acceleration over a long period of time.
Bill Gill
