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How do I calculate the reduction in required escape velocity at various elevations? Or, what is the advantage of increased elevation to distance traveled for a model rocket.

Assumption(s):

I have a model rocket that weighs 1kg (including engine) that is launched from the surface of the earth (assume radius 6371km) and the engine is able to lift it to 100m.

Question:

What is the formula to calculate the distance traveled if the same rocket is launched from an elevation 20km above the surface (i.e. 6391km). I'd like to make a spreadsheet formula to do the calculation for various rocket weights, engines and various elevations.

Assume no atmosphere, or let's not worry about friction loss at this point in time.

Thanks in advance

Agent Smith

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