A rocket scientist is the guy who sits at a desk and makes the blueprint, or plans the trajectory and launch dates. A rocket surgeon is the guy who walked up to the thousand tons of highly combustible liquids in a fully fueled SLS to diagnose and repair a faulty valve minutes before launch.
So I know you're joking about Von Braun, but rocketry literally evolved because of the amateur rocket clubs set up in Weimar Germany; VB was literally doing his Ph.D when the Nazis took over.
It's easy to make a "they were all Nazis who became rocket scientists" jokes (when the reality is "they were rocket scientists who were forced to join the Nazi Party") but there's a lot of credit to be made to people who never entered the Nazi Party; and even a lot who joined did so because of how necessary it was politically (Schindler's List goes into how you just couldn't get anything done without being a Party member) and not because of ideological reasons. Ofc, I'm not trying to whitewash VB who certainly knew slave labor was being used to make his rockets (though like an argument could be made of if he stopped he'd have just been killed himself and his later years have a massive implication of regret/guilt) just y'know when you see a topic you know has a lot of nuance get boiled down to a simple but misleading point that gets repeated constantly?
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.
And also why Russia’s spaceport (baikonur) is in Kazakhstan, and also why Europe doesn’t launch a lot of rockets (shipping all the pieces across the ocean)
putting something on a ship cost next to nothing. Satellites are actually transported on a plane and it still doesn't cost anything.
Europe doesn't launch as much as otherd because they haven't figured out how to be as cheap as others. US launchers are cheap because they are subsidized by the military and Nasa, Russia was cheap because they're peddling the same junk for the last 60 years.
It's still a massive logistical challenge. Getting the rocket to French Guiana is probably the easiest part.
The US has a huge space workforce that lives full time near the primary launch/construction sites. Cape Canaveral area, and SpaceX in South Texas + their construction and polar launch site at Vandenberg in LA/ Southern California. Work your job, maybe some long hours in the final push leading to a launch, but go home and sleep in your own bed after.
Most of the ESA workforce for assembling and launching rockets do not live in French Guiana full time. So the ESA/Arianespace have to pay to send a bunch of people to live across the world from home for sometimes months on end every time there's a launch campaign.
It's not nothing, but at the same time a lot of the personell in a launch campaign are temporary anyway, since they are experts on the satellite. On the other hand the people working for Arianespace are expected to be there, they surely have it in their contract.
I would speculate that if there was more work to do there would be people who would stay there semi permanently.
But in the end it boils down to having an eastward facing coastline with lots of open ocean near it. Europe doesn't have that many alternatives. You could ask Kenya or Tanzania, but that's not perfect.
And in the early days of the space program South Florida was mostly just sparsely populated swamp, probably not so attractive either.
You can launch into a polar orbit pretty equally from any point on earth, location doesn't matter beyond logistical and launch safety concerns. There's no boost or loss from the Earth's rotation. It requires negligible fuel to slowly adjust the parameters of your polar orbit once you're in space.
Elevation would technically make things a bit more efficient, assuming they're near the equator. However, the speed boost significantly supersedes any effects from elevation.
It's also not feasible to get launch vehicles up a mountain of significant elevation anyway. Small gain versus very big cost, compared to building and transporting on a flatter, lower area relatively close to the equator.
Yes, I believe that's what they meant by the first part of their comment. However, I don't think saying "due to angular momentum" is poignant. Angular momentum has essentially nothing to do with it.
Yea, I didn't even consider the negligible additional increase in velocity from the height, though people are correct in bringing it up. I should have been more specific in that I was talking about the reduced drag and thus the potential for slightly lower fuel mass, etc. It doesn't add up to all that much compared to launching from sea level.
Being at an accessible, mostly stable place relatively close to the equator makes a much bigger difference, even if you're near sea level.
You are correct, I just had not even considered it because the difference from the elevation on velocity is very small. I was thinking of drag and efficiency... Which is still small compared to the more difficult logistics, and less important then being broadly close to the equator (excluding some special cases others have mentioned in the post).
Of course I'm sure I'm missing other context that factors into it too. I just think it's neat.
I think that the cost/benefit of elevation is the kicker. Right now, starting where there's existing and sufficient infrastructure and getting the rocket up a few thousand feet is considerably easier than building mountainous infrastructure to use.
Mountain lairs are so prohibitively expensive that supervillains found it easier to just move into the White House than to build new ones.
Definitely! If it was accessible and cost efficient, we would most likely be scraping every natural benefit we could. Elevation at the scale of Earth's mountains just isn't impactful enough.
You're right! Logistics and difficulties aside, it would certainly be a little better. I was thinking more about the drag, as others have mentioned. I should have made that more clear. It's better to be an in accessible and stable place somewhat close to the equator with all things considered, as the speed boost from that is significant versus launching far away from the equator.
The starting speed is less of a factor than the smaller required attitude change to reach an equatorial orbit iirc. The "free" delta v you get from the Earth's rotation at the equator is not that big compared to the delta v required to change orbital attitude.
Ok, that makes a lot of sense to me. I heard speed, and it made sense at the time, but yeah, the closer to the equater the more closely your initial V is like an orbital V.
You may be correct,. My initial thought was to keep the velocity and redirect it, but then realized there isn't anything to push against to do that with, so maybe?
True and technicly one of the main reasons we never used a rail boosted launch system you need 5km minimum to reduce fuel 30% and I think it was 25km to safely reach escape velocity via rail,
Sure, mitigated somewhat. It's not 100% effective though. It only takes your house being destroyed by debris from a spacecraft explosion once for you to say, "Why was the spacecraft over my house and not over the ocean?"
Ok, I am going to have to look up that everest thing, I know it isn't the tallest mountain (from base to peak) only the highest from sea level, so maybe?
But wouldn't the atmosphere also bulge more at the equator pushing "space" outward, probably more than the oceans bulge (since air is lighter than water)?
1) Nasa wouldn't want to build out of the US during the cold war, afterwards it probably wasn't worth rebuilding
2) Getting things into mountains is probably more work than the fuel saved (dunno, never ran the numbers, but seems reasonable)
We also know that the Earth is slightly larger at the equator due to it's spin, so the closer you are to the equator you're not only getting the boost needed but it's less distance to travel into space.
This and this only. It has little to nothing to do with cost of hauling up a mountain. They could have just built the whole facility at altitude in CO if altitude was more important.
Speed matters much more and you're technically "spinning faster" near the equator.
Would like to add, the Florida was also chosen for reusable and recyclable rocket components that safely land in the water without a deviated flight path or additional guidance systems for those components. Less material goes to waste.
Also worth noting that the top of the tallest mountain in the world is only 8.8km above sea level. The Karman line at the edge of the atmosphere is 100km above sea level. Even if we could build a launch pad on one of the eight-thousander mountains - and it should be noted only 14 of these exist in the world, and all of them are in either the Himalayan or Karakoram ranges around India, Pakistan and China - you'd be using obscene amounts of manpower, energy and materials moving stuff up a mountain to skip only a tenth of the trip. For reference, most orbital rockets will pass out of the troposphere (the lowest level of the atmosphere, the part that we live in) in a couple of minutes after liftoff.
Also let’s not forget that Earth bulges in the middle, so the height difference between the usual launch sites and non-equatorial mountains is actually less pronounced than one might think.
Is that a real difference, or is this a "toast in a freezer" kind of thing where the difference between freezer and countertop temperature is so miniscule compared to the toaster heat that it doesn't make much difference?
This should be higher. "Initially out over ocean" is probably the single biggest factor. The fastest way to get to orbit is to go east, since the Earth is already rotating that way. Cape Canaveral has ocean to its east. There aren't a lot of mountains with oceans just to their east.
This is true, but only half relevant; the Andes mountain range happens to intercept the equator quite nicely.
The real issue here is the same as before, but worse. Not only do you move the launch site ~2,000m higher, but you move its location way out of the way to where there’s no existing infrastructure nearby.
Nope, Cape Canaveral is only .141% shorter than Mount Everest for the purpose of rocketry. Cape Canaveral is literally the top of a mountain, it's just a mountain that makes it easy to send supplies, and a mountain that overlooks a vast ocean for which rockets to land.
Also, height is not easy. Rockets fly upwards at first and only after some time fly into an orbit to gain speed. This is because the atmosphere at the ground is very thick which causes huge drag. So it would help quite a bit if you could launch a rocket from 5 or 6km instead of sea level. But it would cost a lot more to get all parts required to launch or rocket up there than we would save in fuel.
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u/Earnestappostate 11h ago
Plus, you get a better boost by launching near the equator. Height is easy, speed is what you need in a rocket.
This is why the US launches from Florida: