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A comment on Virgin Galactic successfully reaches space. Parent comment

Re:Virgin Galactic successfully reaches space by sonnyblarney on Thursday December 13, 2018 @09:25PM (#18677944)
The force of gravity is always orthogonal to the direction of motion when in orbit. So never loses momentum. Which is why the moon is still going around the earth a billion years later and has not 'fallen' into it.
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Re:Virgin Galactic successfully reaches space by Armisael16 on Friday December 14, 2018 @10:51AM (#18681631)
This is only true for circular orbits. It’s pretty transparently obvious that elliptical orbits move closer to and farther from the center of mass (and lose and gain momentum accordingly).
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Re:Virgin Galactic successfully reaches space by ethbro on Thursday December 13, 2018 @09:59PM (#18678094)
We're talking suborbital velocities here.

If I'm wrong, I'd love to hear exactly why, but regurgitating basic physics doesn't resolve the difficulties in modelling a straight flight path around a curved surface, in relation to a dropped object.

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