This, and going sideways really really fast is the way. The highest I've seen is 1500mph.
I crashed at 2499.1 mph by going sideways for a long long time. How accurate is your physics? If I hit orbital velocity, will I just orbit the moon? What if I hit escape velocity?
That is amazing. Not accurate at all really, unless the moon was an infinite plane I guess. If you hit escape velocity you'll never land!