Since orbiting isn't about altitude, but is instead about velocity (orbiting is the art of throwing yourself at the ground, and missing because you're going sideways so fast), the final goal is to have a heap of lateral velocity so that gravity is merely curving your course, instead of actually pulling you to the ground.
The most efficient flight to orbit is ...
From Stardust Generation 1 — bluShift Aerospace:
Basic testbed launch vehicle for experiments requiring subjection to the vibrations and accelerations of launch and parachute recovery. Ideal for student and budget payloads.
Based upon the mission parameters of the testbed and an altitude of 5000 ft, means they can do it anywhere. Factor in ...
Yes, but atmospheric drag is nearly negligable.
To get into orbit, the rocket has to expend energy doing several different things, and they each have performance constraints that affect the structural weight of the rocket.
Roughly in order of fuel consumption, the rocket has to
Gain orbital velocity (a reversible kinetic energy term)
Overcome gravity loss (...