[Two_Sheds]

I also can't help but notice your moving the goalposts yet again. I post 285 you refer to "surface-to-space" and in post 289 you move on to "surface-to-orbit".

Quite a difference.

[GourmetDan]

That's because I was being more clear than orion. He was able to move the goalpost from 'orbit' to 'Mars' with his definition, as he clearly did.

Also, there is no difference in the calculation, just in the coordinate system which basically means where you put your fixed point. So it is another distinction that was lost on most.