| Well, if you take the sentence: >The energy needed is the square, i.e. 9 units for space and 900 for orbit. at face value. It is either claiming that 9^2 = 900 or, it either mistated the units for space or mistated the units for orbit. This is incorrect. If you take into account the context of the prior sentence: >Getting to space needs ~Mach 3, but GTO orbit requires ~Mach 30. you can probably work out 3^2 = 9 and 30^2 = 900. However, as InclinedPlane said, that's only in an idealized number, in reality, you must expend even more energy than that to achieve Mach 30 from the surface of the Earth. We can check back to the prior contexts: >Congrats to Jeff Bezos and the BO team for achieving VTOL on their booster >It is, however, important to clear up the difference between "space" and "orbit", as described well by https://what-if.xkcd.com/58/ To be short: you'd need to find where Jeff Bezos or the BO team claimed anything about "orbit". Since others have already given up on this conversation, I probably will too. |
You seem to understand it later, where you say that 3^2 = 9 and 30^2 = 900, so what's the deal?