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Let's talk about "orbital velocity." Wait no, let's talk about "orbital energy" instead. The sum of kinetic energy (related to velocity) and potential energy (related to height) is really more relevant to the question of 'are you in orbit?'. So... Here is the plot of E_t, the specific energy (energy per unit mass) of the trajectory, versus apogee height, for: (1) circular orbit, (2) orbit with perigee just above the atmosphere, (3) orbit with perigee at the Earth's surface (bad idea). (2, 3 on top of each other at this scale.) E_t = 62.5, or (on the right hand axis) C3 = 0, corresponds to Earth escape. Here's a zoom in to low orbits. A recent flight of interest is plotted with a cross. To be considered 'orbital,' you for sure need to be above the red line, really above the green line, and it would be nice to be at the blue line.
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