it's dangerous, I think sherpas are so tired of rich mf showing off by climbing some hill, so at first possibility they will hijack the rocket and run to Mars
Not much climbing involved in that one. Olympus Mons has such a wide base and gentle slope that if you were standing at the peak the base would be out of sight over the horizon
To be fair, it’s not the cost of the fuel itself that is an issue for rocket launches, just that so much of it is required, and it adds so much weight to the rocket. Fuel is less than 1% of the cost of a rocket launch, yet typically over 90% of the mass of the entire launch. If you could somehow spend fuel on the ground moving things to an optimal launch point to have to put less fuel in the rocket, it would absolutely be worth it.
The real issue is that launching from a mountain would not save you much fuel anyways. To get to orbit requires you to go very fast sideways. The initial “upward” part of a launch is just to get past the thickest part of the atmosphere, then it quickly pivots sideways for the majority of its journey.
You save more fuel by launching from a lower altitude closer to the equator, where you can take more advantage of earth’s spin to gain additional sideways velocity. So we do spend a lot of fuel to do this, for example SpaceX manufactures their rockets in Hawthorne, California, where there is a lot of aerospace manufacturing expertise, and spends a lot of fuel to ship them to Cape Canaveral, Florida, which is closer to the equator.
The radial difference between equatorial sea level and the peak of Mt Chimborazo is about 0.1%. It provides very little benefit but would be a logistical nightmare to launch from.
We'd be better off building a electromagnetic launcher up the side of it and then we can put everything at the bottom and save fuel by using solar wind and nuclear to juice the em rails.
You'd have to engineer the payload to withstand ridiculous acceleration. No big deal if the payload is a HILE projectile but if you have living things or moving parts, that can be trickier.
Equatorial launches are cheaper, but not because it is easier to enter the orbit, but because it is easier to get to the desired orbit(inclination and parking orbit, this is from my memory of playing RP 1 in KSP, may not be correct)
Eh, you an orbit at any inclination you want and park in any orbit you want, but the reason the equator is useful is because you do get that added speed boost and most interesting things beyond earth are also on that plane (like the moon and geostationary orbital distances).
But there are tons of reasons to launch in more high inclination orbits too and a good chunk of satellites are launched in those orbits because they are better for earth observation (since you go around up and and down and the earth rotates under you, so every pass you get a different slice of land under you on the day side of the earth).
SpaceX is putting a launch site in South Louisiana for the same reason. There is also an advantage of movement of parts by water, from either the Mississippi, through the Panama Canal, or down the East Coast.
Pretty sure yall know our reputation for flatness and sea levels. Solid rock and high ground is pretty much non existent, in most of the state. Our only "mountain" is something like 300ft.
If you could somehow spend fuel on the ground moving things to an optimal launch point to have to put less fuel in the rocket, it would absolutely be worth it.
Yeah, ultimately to get more effective rockets without just making "more rocket" requires a huge amount of ground infrastructure.
This is also the reason the European Space Agency primarily launches in... South America. Fresh Guiana to be exact, which is super close to the equator whereas Europe is not.
Seems like the easiest way to solve both the sideways velocity and the less fuel problem would be to use a giant maglev / gauss cannon track to get the rocket up to speed before activating the thrusters.
Hell, we could use a mountain to brace the track. What kind of speeds could we get up to with a maximum track height of Mount Whitney, or Guadalupe Peak?
There a lot of logisitical reasons, like transportation to the top of the mountain, fuel, bad weather, high winds, all the support strcutures beyond the launch pad, and what happens if something goes wrong and you dont have a big open ocean for falling debris.
I suspect OOP belives the increase in height is beneficial, but even if we built a launch pad on Mt. Everest, it would be neglible. The Earth has a 4,000 mile radius, and Mt. Everest is only 6 miles high, a diference of 0.15%.
The biggest reason for our launch pad sites is escape velocity. On Earth, you need to get to 25,000 MPH to get into orbit. As our flerfy friends like to point, the Earth spins at 1,000 MPH, but that is only at the equator, where all the launch pads are. As you travel to the poles, that rotational velocity goes down until it goes to 0 MPH at the poles. If you need to get to orbit, get a running start at 1,000 MPH gets you 4% of the way there, a significant savings in fuel.
At fhe end of the day, a rockets mass is 90% fuel alone, 5% is the rocket shell, and 5% is the payload. so any savings that can be achieved on fuel is signficant.
The radius of Earth is completely irrelevant. The problem is the dense portion of the atmosphere near sea level, which prevents a rocket from rolling over and dumping its energy into horizontal motion. The atmosphere at the top of Everest is about 35% as dense as the atmosphere at sea level. Everest is also closer to the equator than Cape Canaveral.
If it was logistically possible to launch from Mt Everest, it would definitely be worthwhile. Between reduced drag, earlier gravity roll, and improved specific impulse, I think it would save about 300 m/s to LEO, plus whatever advantage the ISP provides. The rocket equation being certifiably nuts in its exponentiality, that's about a 12% reduction in fuel required at launch.
This is completely wrong. The earth's spin in incredibly important. The European Space Agency literally launches from French Guiana in South America because of the rotational slingshot effect.
The spin is extremely important; I never said it wasn't. However, the percentage increase in distance from the center of the planet (and therefore the radius) isn't part of the reason that launching from high altitude is beneficial. The increased velocity from that is negligible. Hence, it is completely irrelevant to this discussion.
You're wrong. Launching from the Equator vs launching from Canaveral is only 80m/s difference in dV. (Earth is spinning at about 400m/s at canvaeral vs 480 at the Equator) If you launch due east. That's very small, even considering the rocket equation. A rocket needs 9 - 9.5km/s to get to LEO, depending on gravity, cosin and aerodynamic losses.
The reason they launch from there is that you can target a very wide range of orbital inclinations AND you can launch east over the water so spent stages fall someplace safe. You can't get that launching from anywhere in Europe.
The difference is absolutely not negligible. Measuring the difference in relation to the radius of the Earth is completely irrelevant, it doesn't really factor into it at all.
Rockets use most of their fuel at the very start of the trip, pushing through the thick atmosphere. Launching rockets from the top of a tall mountain would absolutely be a good idea from the perspective of theoretical rocket performance.
The only real issue is the logistics, as you pointed out.
There have been plenty of schemes to launch rockets from airplanes to skip the difficult first kilometres. That of course comes with its own set of problems, but, it would be worthwhile.
Logistics are the issue? So the European Space Agency ships all of their rockets across the ocean to French Guiana to launch them close to the equator at sea level just for fun?
You're just completely wrong. Roughly 90% of a rocket's fuel goes towards achieve the necessary horizontal speed to get to orbital velocity. Of the 10% that goes towards elevation gain, almost 90% of that goes towards combatting gravity drag rather than combatting atmospheric drag. Only 1-2% of a rocket's fuel goes towards atmospheric drag.
certainly. This is a big problem, transporting fuel can lead you to lessen the efficiency of the fuel (you need too much energy to transport it compared to what it gives).
One of the reasons why the green hydrogen technology is not working as desired.
You still need to construct a catching pad on top of the mountains which requires a lot of fuel besides mountains aren't the most stable places to build a structure like that.
While it's true that the spacecraft is designed to be temperature resistant, the insides of the spacecraft ain't.From computers to magnets they need to be insulated beforehand being sent and built on a mountain.
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.
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.
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.
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,
Florida is also further from Earth’s center than most mountains that are further away from the equator due to the earth not being a perfect sphere. Not sure if that helps the rockets, not a scientist.
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, 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)?
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.
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.
That’s wrong. The speed difference at the equator is less than 500 m/s, and that only compared to the poles. This is a really small factor. The real reason for launching closer to the equator is due to being able to go directly into a wider range of orbit’s inclinations. If you launch from a higher latitude then inclination you’re aiming at, it still can be changed in space, but anyone that’s played a bit of Kerbal Space Program knows how insanely expensive it is, sometimes taking almost as much fuel as for another launch.
Lower air pressure. Rocket engines have to be optimized for a range of pressures for maximum performance. Small nozzles near sea level and large nozzles in vacuum. Too narrow, and the exhaust expands sideways and you lose thrust. Too wide, and you get back flow around the rim of the nozzle and lose thrust.
That first mile gets you down to 0.82atm already, so you can optimize for a much larger range of altitudes on your first stage.
While this is true, our ICBM program showed us the differences are extremely minute and easy to compensate for.
The same Nike for example can launch from Pacifica California (100ft) or Mount Gleason (6,500ft).
The difference is almost completely ignored beyond tracking needs, because the point of the rocket is SPEED. It's actually about the rockets ability to get to speed, not just to climb altitude. That's where the fuel goes, it's for acceleration, not just raw thrust.
The difficulty for a rocket is not the ascent, or to get over the hurdle of atmosphere, it is to gain speed second by second. You have to be at or exceeding 17,000mph by 250 miles high to stay in low earth orbit. Shaving a mile off the launch and making it 17,000mph by 249 miles high, effectively doesn't change the math at all because that first 5000 feet on launch is completely negligible regardless of altitude, it's simply establishing forward inertia.
And, it'd save us almost nothing (even if we had a magical teleporter that let us get everything up there insantly and for free).
Space is a minimum of 50 miles from "ocean level" (and really, it's 62, but let's say 50).
Everest, the tallest mountain, is about 5 miles above sea level.
So, even if we hauled everything to the top of the tallest mountain on the planet (which would be an insane to impossible amount of effort), it's only reducing the distance by less than 10%.
EDIT: Thank you to the 500 people that have told me "the distance barely matters". That is pretty much my point. YES, I know speed, and thus latitude are more important. My point is even if you ONLY consider the height, the thing the original question focused on, it STILL doesn't matter. When you factor in all the factors, it really, really doesn't matter.
I focused on the focus of the post in my response, not all of astronautical engineering.
Unless you are doing sub-orbital flights, the height doesn't matter all that much. If you are looking for orbit (most space launches), speed is way more important than how high you start. Launching at the equator gives the highest starting speed, a far more significant savings in fuel. Now, there are equatorial mountains in the world, but as you say, you still have to expend the resources to move all the rocket parts and launch facilities up the mountain. It's easier to just build your rocket slightly bigger and use slightly more fuel to launch from a much more accessible and convenient location.
Launching in thinner air actually saves quite a bit of fuel though, a lot of it is just spent fighting drag in the lower atmosphere.
The real reason we don't do this is just that there are like a dozen other more important things that make a good launch site and it's not practical to find a place that checks all the boxes.
You need to be close to the equator, directly west of a large body of water, governments want to launch in their own territory, etc, etc.
So why don’t we save fuel by thinning the air first? I’m thinking a giant dome with massive vacuums all around it, creating a low pressure bubble over the launch pad.
Except the lowest part of that 50 miles is the densest atmosphere. So lessening the distance by 10 percent is only some of it. The reduction in atmospheric drag is an entirely different beast
Finally! Here's me scrolling through hundreds of comments and no-one's mentioned the weather!
A normal winter frost doomed Challenger, I can't imagine trying to combat the winds and temperatures at those heights. Not to mention the snow.
Well, im sure the rocket scientists have run the numbers and realised that rocket + fuel for 4-6 extra km< rocket+ fuel PLUS rocket launching platform for many many extra horizontal km's and those vertical km's you gain by climbing the mountain.
That shouldnt matter though. In terms of cost to get to the top of the mountain.
The biggest issue for a rocket is that it has to haul it's own fuel. It's not a cost discussion. For every pound of payload, you need 3000 dollars worth of fuel. But then you also need another, 6000 dollars to haul the fuel for that pound of payload.
The problem with the mountains is more like - they aren't nearly as helpful as they are providing draw backs. Temperature. Location, and realistic benefits. The height would help, but it's not like mountains are half way to orbit. They are like...3% at best. Tallest mountain is like 7 km I think? And the average orbital path is something like 300 km?
Shrunk down to the size of a bowling ball, the Earth would be much smoother than a bowling ball. Mountains are basically a rounding error in terms of spaceflight.
NASA Everest. Sherpa's hauling all the astronauts gear up as they try and get to the summit to load into the shuttle before the next storm comes in and strands them there.
I hate that this has the most upvotes currently, because it is clearly the wrong answer...and I'm guessing you haven't studied rocket science either.
The most important part about a rocket launch is reaching the velocity need to escape the gravitational pull of the earth. The earth is "spinning fastest" at the equator because a rotating sphere has the same angular velocity everywhere on its surface, but tangential speed (speed of a launch) increases with how far out you are from the axis of rotation, which is greatest at the equator.
A more practical example would be how an object on the outside of a record on a record player is moving much faster than an object on the inside of a record, despite them completing the same number of revolutions per minute.
Also, your answer is just kind of wrong because for most EU countries it would much cheaper for them to establish a launch site in the Alps than ship everything to the other side of the world where their launch site currently is (French Guiana, South America).
Not really the correct answer. Logistically that could be overcome. The fuel cost of entering orbit isn’t up, its horizontal. You need enough horizontal speed to miss the earth as you fall around it.
Yes, but not the real reason. Horizontal speed is where most of the energy goes. Climbing in altitude is the easiest part. You can reach space for under $100k easy, but you're going straight up and coming back down.
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u/rysy0o0 11d ago
It would cost a lot of money to haul all the rocket parts and fuel on top of a mountain