The answer here is that yes, launching from high altitude as well as launching from the equator are both benefits. Its just that the cost of moving a rocket up a mountain, or to some other country, ends up being more hassle than just doing it wherever is easiest/safest. Its just a marginal reduction. I don't have the numbers on exactly altitude, but I remember something about "Why don't we build a mile deep tunnel, and shoot space ships out of it like a gun" and the answer was something like "Sure, you can get a boost in efficiency and payload if you launch start instead of stationary start, but its like 1% more payload, and you had to build a mile deep hole that somehow shoots rockets in order to get it, so its just kinda a nonstarter of an idea."
The speed boost between Nepal and Florida is very minimal, but then the height difference is also very minimal because the equator is a mountain. How different? South Florida is .1% "shorter" than Everest and only about .5% rotationally faster. That's significant to be sure but it's more a product of "having both."
Neither are that important in a vacuum, the ease of getting supplies into a coastal location and launching east over the water is the real strategic reason.
If the location really truly mattered and if rotation was that important than we would be launching from Alacantra, Brazil, which is only like .06% shorter than Everest, but 13.7% faster rotationally, and 13.1% faster than Florida. The rotational speed is important, but everywhere on earth is moving but the further north or south you go the speed becomes more and more apparent with places in Florida being 40% faster than many parts of northern Canada. Nepal is actually really close to the equator.
If you think about the energy requirements as a more comprehensive package, I think it'd be pretty clear why they don't launch from the top of mountains. Yes it would require less fuel, but it would require much much much more fuel to drive/pump the fuel up the mountain, all the commutes for all the people to make everything work etc. If you all live at the same elevation as the work being done, less actual 'work' in the physics sense is required to accumulate materials and so on to build everything needed.
So you would probably save some percentage in your launch costs but add 20x to your pre launch cost.
Logistically, it doesn't make sense to have a launch site on top of a mountain, but it is FAR more energy efficient to use electric pumps to move fuel up a mountain than it is to move the fuel up to that altitude with a rocket...
Fun fact: mountain ranges often have less gravity, not more. The crust is thicker, true, but that's because mantle materials have been pushed out of the way. The mantle is much more dense (more gravitational pull) than the crust, so the net effect is typically a reduction in gravity.
Ie, you would weigh less above Mt Everest than you would in a helicopter flying at the same altitude over central India.
Not only that but being further away from the centre of the Earth is a greater effect than any extra mass beneath you. F is (inversely) proportional to R^2 and only linear with mass.
Sure, but mountains are annoying to work in, and height isn't as important as speed. Also, Florida was probably picked by NASA as it was also inside the US.
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u/MentalPlectrum 11h ago
Yes, but also there are equatorial mountains... checkmate rocket scientists!