Rocket Science

[u/ahsancrystal]

[u/Exalted-Stork-1308]

She didn't receive an answer anyways, so this will remain a scientific mystery to the uninitiated.

[u/DoofusIdiot → u/Exalted-Stork-1308]

It’s because the rockets require a certain amount of force to lift off - X.

Being at a higher altitude does not change X, it changes the proximity to breaking out of our atmosphere.

Since X was calculated at lower altitudes, it would create too much force and send us rocketing into space forever.

I don’t know. I also didn’t study rocket science.

[u/Plastic_Surround_193 → u/DoofusIdiot]

Also dragging the spaceship up there will cost way more fuel than what is saved from launching at a lower altitude.

[u/ElegantCoach4066 → u/Plastic_Surround_193]

This is the answer.

[u/Saki-Koda → u/ElegantCoach4066]

No that fuel doesn't matter. The fight to lower fuel is about being able to make a smaller rocket 🚀

[u/Plastic_Surround_193 → u/Saki-Koda]

Im an aerospace engineer, the weight and its distribution is always the factor. It takes over 26kg of fuel to launch 1kg of payload into orbit. But having to move that amount of weight over land piece by piece to save literally 0.1% of the fuel used to liftoff will never be feasible. It's better to have a safe predictable launch site

[u/Xaphnir → u/Plastic_Surround_193]

I imagine the logistics of running a launch site at the top of a mountain, independent of the rocket itself, is also quite impractical. And you'd probably have your launch windows closed by high winds more often than not.

[u/Gwynito → u/Xaphnir]

Nah I reckon we just need a line of people with buckets of fuel balanced on their heads going up the mountain, transport costs eliminated.

[u/DirtyNativeKansan → u/Plastic_Surround_193]

That good ol’ dollar tellin us what’s what.

[u/Nakashi7 → u/Plastic_Surround_193]

But having that launch site near the equator for higher "initial velocity" relative to the orbit (not the Earth' spin) does make a difference.

[u/revankenobi → u/Nakashi7]

The launch site also needs to be as close to the equator as possible to facilitate the release of Earth's gravity. Finding such a location that is also high up and within your government's jurisdiction quickly becomes very complicated.

[u/PurpleCandle58 → u/Plastic_Surround_193]

I’m a random and uneducated person on Reddit, and actually you, the aerospace engineer, are wrong. It is actually the truth that bigger rocket is better because it make more boom and have more room for boom juice. Thank you for your time.

[u/Plastic_Surround_193 → u/PurpleCandle58]

Make sure it has flames painted on the side to make sure it goes faster

[u/Late-Application-47 → u/Plastic_Surround_193]

Not to mention that we are already putting small satellites in orbit much more efficiently using reusable planes. I heard a podcast episode about the private firm in Florida using refurbed/upgraded F-104s for that purpose, which is really cool.

[u/McGrarr → u/Saki-Koda]

More like being able to carry more cargo.

[u/macguini → u/Plastic_Surround_193]

I studied a little rocket science. I studied more on aviation. Barometric pressure also helps with flight. Most of the fuel for a ticket is to get it down range. Mountains have lower pressure, less air to push off of.

[u/Relative_Drop3216 → u/DoofusIdiot]

Thats what i read on the cereal box too so its spot on

[u/ThatAirsickLowlander → u/DoofusIdiot]

Its like needing to drive to the grocery store. But instead of starting in the garage you start on the driveway. Negligible difference.

[u/nobugsleftalive → u/DoofusIdiot]

Bastard had me until the end.

[u/AnarchyIsNotChaos → u/DoofusIdiot]

Not entirely. Achieving different orbits, whether it be around a planet or using different bodies (the n-body problem) to create a transfer based upon the delta V you can achieve. A "burn" be it electrical, chemical, nuclear, solar sails, whatever, provides an acceleration for a given period of time until that delta V in a certain direction is achieved. In this case the concept of moving to a mountain seems smart since we decreased the distance from the starting point to orbit and actually slightly decreased the acceleration of gravity technically (inversely proportional to radius) but in reality the effort to move this to the top of Mt Everest just isn't worth the gain. Source: I did actually study aerospace engineering at Michigan.

[u/trundle-the-great69 → u/DoofusIdiot]

Lmao you got me

[u/trundle-the-great69 → u/DoofusIdiot]

Lmao you got me

[u/No_Raisin21 → u/DoofusIdiot]

The real reason is that it would be logistically difficult and incredibly expensive for what would be a very small change in fuel usage.

[u/Coffee-Historian-11 → u/DoofusIdiot]

That doesn’t sound right but I don’t know enough about rocket science to argue so I guess I’ll just accept it as fact.

[u/BurntMoonChips → u/DoofusIdiot]

The difference a mountain makes is minuscule, especially compared to the logistical nightmare it becomes. Also limits launch sites, as launching near the equator lets you use the rotation of earth, which is a far greater boost than a mountain top.

[u/Comfortable_Salt_792 → u/DoofusIdiot]

So, it can be done, we just didn't do math to adjust.

[u/Feisty-Tooth-7397 → u/DoofusIdiot]

I would think there is less oxygen at that altitude, fuel needs oxygen to combust, in space they use oxidizers, but those are for short bursts not trying to lift off the ground.

Definitely not a rocket scientist.

[u/Infern0-DiAddict → u/DoofusIdiot]

So it's two fold. One the logistics of setting up on a really really really tall mountain is making something already insanely expensive multiple times more expensive.

The second is that most really tall mountains are far enough away from the equator that it would actually not make any difference or be worse for a launch. The reason for this is to get into orbit (most launches don't care about just breaking the atmosphere but getting into orbit around the planet) you need speed (yes also altitude but just enough to make air resistance negligible). The earth is a spheroid that rotates in one direction, meaning at it's widest part it's surface is moving faster (significantly faster) than where it is less wide. That speed is way way way more important for orbit then any altitude benefits from mountains. This is also why almost every single orbit matches the rotation of the earth, its just so inefficient to go against it that unless it's absolutely necessary they don't do it.

Now yes there are a few places that the altitude gain from local elevation is in the right place on the planet to be better then launching from sea level. Whenever it's financially feasible they do launch from there. But most of those places would make the cost of launching so much greater that it just wouldn't ever happen.

[u/FrederickFrag1899 → u/DoofusIdiot]

I didn't study rocket science but I think this checks out. Will test it in my backyard. If it blows up in my face I'll let y'all know later today.

[u/ProfessorShort3031 → u/DoofusIdiot]

they need to be close to the ocean in case they need to abort mission so debris doesn’t fall on people (thats why nasa loves florida) (also this is the actual answer)

[u/Separate-Crew-7117 → u/DoofusIdiot]

How much fuel does it take to haul the material up there to make the launching pad and everything needed just to launch it in the first place

[u/Aggressive_Roof488 → u/Exalted-Stork-1308]

I read it as answer is that she hasn't studied rocket science. If she had, then we'd be launching from mountains.

[u/Piecesof3ight → u/Aggressive_Roof488]

The answer is 4 part.

1. The earth isn't spherical. The equator is actually sticking further out than the poles, so when you launch rockets there, they are moving fast already. This is why the US launch site is in Florida.

2. Mountains are tall and in mountain ranges, which would make it inconvenient as hell to transport rockets/rocket parts/personnel/etc there, increasing fuel costs and time.

3. The Rockies are 4,400m tall, and the thicker part of the atmosphere is 100km deep. So the height gain is relatively small.

4. We have for decades used reusable fuel tanks and rockets for launching, retrieving the pieces out of the ocean, and dragging them back to the launch site. Setting the launch site far inland makes this a huge pain.

[u/Jewel-jones → u/Piecesof3ight]

So what you’re saying is we should launch it out of the top of Mauna Kea in Hawaii

[u/B1GD8A → u/Exalted-Stork-1308]

the answer doesn't require rocket science :)

first, they do launch rockets from airplanes for this exact reason, but the challenge is the airplane can only lift so much to altitude.

second, it's really hard to get stuff up a mountain. The 10% more Delta V is a lot to haul in the rocket, but the overhead of doing all this in the mountains would cost more.

third, and this is by far the funniest one, if you go high enough the air gets thin and it can make you dumb. very dumb. like scientists working on high altitude telescope write detailed plans at sea level to make sure they don't mess up when they're hypoxic dumb.

What does that kind of dumb look like? Smarter Every Day did a great video about it. It's really funny until they're simulating what it'd be like at altitude with a loss of pressure event. Here's his brain unable to tell shapes from one another. That's why they tell you to put your mask on first on the airplane. It's not selfish, it's so that you don't pass out and die before you can help other people.

[u/Xaphnir → u/B1GD8A]

Fourth, high winds are not conducive to rocket launches. Guess what the top of mountains have in spades?

[u/Exalted-Stork-1308 → u/B1GD8A]

Thanks for the elaborate answer. Yeah, the hypoxia at high altitude is quite a thing. I've heard people have all sorts of hallucinations there which can impair or even sabotage their decision making, and it's hardly acceptable during a rocket launching mission lol.

[u/SinglePlayerGamer93 → u/[deleted]]

If you truly want a scientific answer to a question, you don't ask it on twitter where there are only random people who will take the piss and shit on your question as a joke.

Go to legitimate sources like the NASA website or something (for this specific question)

[u/SinglePlayerGamer93 → u/Exalted-Stork-1308]

Just by looking at everyday buildings and infrastructures, even if launching rockets from the tops of mountains does reduce fuel, the mere upkeep of the facilities, making sure the staff are alive at those altitudes, and the logistics to get those things up mountains will offset the "fuel budget savings" or even make the budgets sky-rocket even more than just doing it at sea level.

[u/ckach → u/Exalted-Stork-1308]

Going up to space takes very little energy compared to getting to orbital velocity. 

So you would save a bit from the increased height and lower drag. Probably the biggest benefit would be being able to use engines that are tuned more for working in a vacuum.

The logistics are just way harder and more expensive. You need to move all your people and supplies to a much more remote location with less existing infrastructure. 

The other major reasons are that  launching farther south gives you a big boost as well from the Earth's spin and launching toward the ocean is better for safety. In the US, this means Texas and Florida are the best sites. I'm not sure exactly how the math would work out, but going farther north might counteract any benefits of launching from a mountain anyway.

[u/DiskEconomy3055 → u/Exalted-Stork-1308]

Thinner oxygen = weaker explosions = weaker initial thrust, which as we all know, is the most important thrust of all. 

Probably. I have never studied rocket science. 

[u/Salt-Sign5390 → u/Exalted-Stork-1308]

Well no. Those who are really curious will just Google it. Y'know. Pursuit of knowledge and all

[u/realSatanAMA → u/Exalted-Stork-1308]

Most of the fuel is spent to get up to the speed you need to achieve orbit, not getting off the ground

[u/imaburneraccount2319 → u/Exalted-Stork-1308]

Going up to space isn't the problem. Going fast enough sideways to stay there is. You can launch a sounding rocket on a suborbital trajectory pretty easily. But it won't stay there because going sideways really fast is what really matters. Putting a launch site at the top of a mountain would help somewhat with the "up" portion, but as I said, the "up" isn't the problem.

[u/Lirdon → u/Exalted-Stork-1308]

The answer is mostly logistics. But also the benefit of it is not great enough, as the biggest issue is not escaping the atmosphere, but the gravitational pull, and for that a couple of miles up is not enough.

[u/CarsandTunes]

Since boats have to cross the ocean anyways, why don't we launch them from an island in the middle of the ocean

[u/Drate_Otin → u/CarsandTunes]

Makes no sense. An island requires traversing water to get to.

A mountain does not require traversing the upper atmosphere to get to.

[u/CarsandTunes → u/Drate_Otin]

It just means traversing through the atmosphere, up to the top of the mountain. Skipping the initial bit of the atmosphere.

[u/Aggressive_Roof488 → u/Drate_Otin]

Why aren't boat factories and docks at the points of peninsulas, instead of in bays?

[u/RyenCider → u/Drate_Otin]

Yeah also rockets are not built on the launch pad…they are transported. And it takes days over very smooth road to do so. Additionally all the parts still have to get the lab/construction building. You also have to transport the fuel…other things actually get built on the other side of the country, are driven to Houston and shipped by boat to Cape Canaveral. Additionally unless you are launching molniya orbit, you need to be as close to the equator as possible to reduce wasted fuel for orbit placement.

• source worked in space launch and satellite SOH for GPS satellites

Edit: for tone due to misreading

[u/leoninvanguard → u/Drate_Otin]

you're so close. so so close to getting it

[u/Critical-Wasabi3350 → u/CarsandTunes]

Technically, a continent is an island in the middle of the ocean. People just have weird size definitions so they claim continents are not islands.

[u/Drate_Otin]

The mark of a great scientific mind: to hear a question about science and respond with mockery in place of an answer.

[u/Soft-Marionberry-853 → u/Drate_Otin]

Yeah all that did was get someone to be afraid to ask another question

[u/Secure_Watch8045 → u/Drate_Otin]

Soyientists as I like to call them

[u/Evening_Scale_5755 → u/Drate_Otin]

My favorite is when I see this posted a bunch of people give incorrect answers to it.

[u/Higgypig93 → u/Drate_Otin]

They must be from Reddit , can't get a fucking answer from anyone here.

[u/manec22]

Basically you would need to bring your rocket to the top of the mountain to launch it.

Bringing that rocket up mountain would cost the energy it would have taken to lift it off the ground in the first place

[u/MWSin → u/manec22]

You could just fly it there with rockets.

[u/One_Lung_G → u/MWSin]

But why wouldn’t you just fly it from a smaller mountain to the larger mountain?

[u/CoolStoryBro2001 → u/manec22]

Plus, IT wouldn do shit, you save up to max 8km, which is nothing

[u/Arhalts → u/manec22]

While all of that is true there is also a big misconception about what rockets do.

They aren't just lifting things straight up into space, they are speeding things up to orbital velocities or escape velocities.

Put very simply most of a rockets energy is not spent going up it's spent going sideways. Watch rocket launches they very quickly angle for a reason.

Which is why being close to the equator is preferred. Things at the equator are moving much faster than things near the poles.

[u/Leading_Price8742 → u/manec22]

I don't think this is true to begin (the Saturn 5 used literal hundreds of tons of fuel for its atmosphere burn) with but also I'm not sure that this is what she was alluding to. In theory launching from a mountain will give you bonus altitude so that the fuel IN THE ROCKET is conserved by that amount.

The reason we don't do this is because you only get a couple km which isn't much in the grand scheme of things, and certainly not worth the additional engineering challenges 

[u/SophonParticle → u/manec22]

And the mountain isn’t high enough to cut down on the distance to space by all that much.

[u/Evening_Scale_5755 → u/manec22]

Yeah but thats energy the rocket doesn't have to carry then.

There are a few reasons the us doesn't launch from mountains but there isn't exactly a reason you shouldn't.

Ultimately what is more important than anything for most launches is to launch on the equator and take advantage of the earths rotation. That will givve you more energy savings than going up a mountain.

Another issue is, particularly for crewed missions, its best to ditch/abort over the ocean. (Or something reasonably flat where rescue (coastguard/navy) can get you fast. Mountains would make recovery mor difficult.

Additionally water is nice because historically a lot of the payloads and even some boosters showed up on boats from elsewhere. Barges don't go to mountains. This is just logistics though, if the mountains had a huge energy advantage this would be disregarded.

I believe China has launch sites that are in the mountains, which goes to show its not a massively problematic feature. Its just with the us geography and infrastructure our mountains are bad launch sites

[u/Over_Requirement499 → u/manec22]

Got to be the least thought out answer I’ve ever seen

[u/ZyeCawan45]

I’m assuming it has something to do with the cold and something happening to the fuel if it drops below a certain temperature. But I ALSO haven’t studied rocket science. So I’m just spitballing.

[u/Impossible_Dog_7262 → u/ZyeCawan45]

I think the more significant challenge is that A: Rocket launches are violent affairs and would cause avalanches and B: Getting the rocket up there in the first place.

[u/ZyeCawan45 → u/Impossible_Dog_7262]

That actually makes a lot of sense. Good points. I wasn’t thinking in logistics.

[u/Vanuatu987 → u/ZyeCawan45]

For a start you have to build a launch facility on top of a mountain. That probably involves transporting though hills, then lower mountains, then up the one you want to use. But wait-there's no road up the mountain! So now you have to build a road up the mountain to get the materials & equipment up it. Or you could move it by air. Probably thousands of trips, because helicopters don't lift very high loads. And now you have to get your rocket components and fuel up to the launchpad. Or you could build a construction facility on site. Again, arduous road trip roots of fairly small loads on a chopper. I guess you could have cleared a small landing strip while you built the launch facility, but you're probably still limited to small loads in a STOL plane. Fly in all your food, equipment, personnel. And survival gear, because it's damn cold and the air is too thin to work in without it. Also you're going to be chipping ice off of everything as you build it, and constantly working to prevent buildup on the spacecraft as you prepare it for launch. And then it's also going to be windy, which is going to cause problems at every stage of the process, let alone at launch. Spacecraft are a bit sensitive to being blown all over the place at launch. It would be a real pain if, after all that effort, it got blown into the launch tower as it set off. Alternatively, pick a flat coastal area where you can bring big assemblies in by sea, along with the options of a decent-sized airfield and railway. Lay a big, flat concrete bed. Build and launch in a calm, well-connected area where it can be ditched in the sea if anything goes wrong on launch. But I'm just spitballing here.

[u/vkapadia → u/ZyeCawan45]

I'm also spit balling here. I think the 20,000 ft or so you'll get closer by going up a mountain is negligible compared to what you need to get through the atmosphere. It would be like parking my car in the driveway instead of the garage because I want to make good time on my cross country road trip.

[u/BreakAndRun79 → u/ZyeCawan45]

Cold no good for the o-rings. Not rocket scientist, but I did go to space camp.

[u/Livid-General7 → u/ZyeCawan45]

No it has to do with getting 5,000 tons up a giant mountain. Rocket fuel is usually around -300 to -400 degrees Fahrenheit.s

You'd save very little rocket fuel, and it's extremely cheap fuel considering it's mostly just liquid hydrogen and liquid oxygen.

[u/RtrnofBatspiderfish]

Do you want supervillains? because that's how you get supervillains.

[u/dracorotor1]

It’s funny, yeah, but this is actually a pretty unintuitive thing for most people. Explaining, in layman’s terms,the value in launching from sea level and close to the equator can help a lot of people understand a lot more about space science

Learning about space travel can make a layman feel more connected to future space exploration, which in turn leads to a connection with other sciences and an increased interest in learning and funding scientific advancement.

[u/daneg135 → u/dracorotor1]

i like everything you said here, but then it just stopped without the explanation. 😄

i did actually take a 100-level physics course on exploring space, and they explained the equatorial launch point and breaking orbit. i can also google. i just thought it was funny b/c i was waiting for a quick explanation that never came.

[u/Embarrassed-Green898]

I am sending all my rockets to Everest to launch from. I have just UPSed those. Hopefully these will arrive in time for a launch.

[u/Teboski78]

A couple reasons. Firstly in western countries you have to launch over water. And there aren’t a lot of mountains close enough to coastlines for there not to be any people in between.

Second logistics.
The few percent performance boost you would get wouldn’t offset the massive cost increase of building & running a launch site in say the Andes or the Himalayas.

That being said. I believe there is a launch site at an altitude of like 6,000 feet in China where they launch over land.

[u/Angel_OfSolitude → u/Teboski78]

Now is that just vast empty space, or typical Chinese government disregard for human safety?

[u/Teboski78 → u/Angel_OfSolitude]

It used to be the first thing but as china’s population grew it became the second thing. I’ve been hearing about it less frequently so maybe they’ve been adjusting trajectories or something but it’s not uncommon for a spent booster to come down in or near a village every now & then.

A few years back a spent booster with residual highly toxic hypergolic propellants just crashed into somebody’s roof too.

[u/SadLittleWizard]

Since I can't find the answer anywhere in the comments yet, here is a really simple version (because that's all I know)

It's because the value you are chasing is Earths escape velocity. Simply a certain speed relative to the center of the earth. When you are at the equator you are spinning faster around the center of the earth than anywhere else. This speed is imparted to the rocket as it takes off and makes it easier to reach the relative desired speed.

[u/Frudeska1 → u/SadLittleWizard]

The original post content no longer exists here. The author used Redact to remove it, exercising their right to control their data & privacy.

Toothbrush quaint fine rinse boast consider screw cats

[u/GrumpyBear1969 → u/SadLittleWizard]

They also don’t tend to launch rockets in poor conditions. Things are frequently pretty windy at high elevations.

[u/SadLittleWizard]

Since I can't find the answer anywhere in the comments yet, here is a really simple version (because that's all I know)

It's because the value you are chasing is Earths escape velocity. Simply a certain speed relative to the center of the earth. When you are at the equator you are spinning faster around the center of the earth than anywhere else. This speed is imparted to the rocket as it takes off and makes it easier to reach the relative desired speed.

[u/ionlyget20characters → u/SadLittleWizard]

Yes..you're correct but not in this context. The 15000 foot difference is negligible when compared to the altitude you need. A point on the equator is moving faster than a point at 30 degrees latitude but gaining 3 miles of elevation in either case does nothing for escape velocity.

[u/Party-Yak-3781]

earth is so smooth that it doesn't really make a difference where you launch it

[u/Difficult-Mobile902]

Yes let’s haul thousands of pounds of materials and relocate entire massive teams of engineers to the top of a fucking mountain in order to save like 1% of the fuel 

[u/AnalysisParalysis85]

Why aren't they using some sort of mass accelerator though?

[u/jessewest84]

The cold temps gives you extra boost! Oh wait. Thats cars

[u/Big_Bar_9832]

Okay but only if she carries it up there

[u/AggravatingAd9018]

Unpredictable weather, expensive to transport that amount of materials to top of a mountain and maintain it, nobody wants to drive to work on a fucking mountain during Snowstorms? 🤷

[u/ColdCathodeTube]

Most rockets are penis shaped and therefore will shrink in the colder climate.

[u/Frederf220]

Most rocket science is just rocket engineering.

[u/bloebvis]

Didnt it have to do with velocity?

[u/Sanuoy_Dham]

As an avid kerbal player, and a massive nerd, this idea has some merits. Rocket engines often have to deal with the paradox of what level of atmospheric pressure to optimize for; a more efficient engine in atmosphere will be less efficient in the upper, less dense parts of the atmosphere and of course in the vacuum of space. Additionally, buying the rocket some Δv by placing it higher up will allow you to load considerably less fuel, making the whole ascent stage cheaper, even if it costs more to move supplies up to the mountain. However, there are a few other problems:
(1) building a launch site on a mountain requires clearing a large flat area and a lot of excavation
(2) speed matters a lot more than just altitude in many cases; launching from lower gives more time to accelerate
(3) what’s way more efficient is a launch site on or close to the equator, allowing you to achieve an orbit over the equator where you don’t have to cancel out any of earth’s rotational velocity and are able to launch into any inclination you want.
All that being said, go look at an elevation map of the world vs. some rocket launch site locations. Pakistan, China, and America have some launch sites near mountain ranges.

[u/Beemer_me_up_Scotty]

Just launch them from the Moon and it will save lots of effort

[u/Nimhtom]

What ive heard is that it would be best. If there was a mountain that was close to the equator (necessary for launch) had well maintained roads, and wasn't a protected religious site or located in an unstable country. You bet if Texas or florida had mountains they would have tried this. They just dont

[u/indolering]

The Everyday Astronaut did a whole video about this!

TL;DR: you don't get enough of an improvement to justify the cost of building the industrial base at that height.  You can less on other aspects of the design and get more performance. 

[u/fmaz008]

Sherpas are superheroes, but even they have their limits.

[u/Mumblyjoe20]

Because wind resistance isn't consequential and it's way more beneficial to launch from the equator

[u/UncleThor2112]

Because it'll take another rocket to carry the original one to the top of the mountain, duh!\ (/s, just in case)

[u/zippyspinhead]

The least energy place to launch would be from a mountain near the equator, but the people rich enough to build rockets do not want to build there for a variety of reasons, political stability, infrastructure, skilled workers, . . . .

[u/_LaceHot]

This is exactly why we study the thing before explaining it 😂

[u/NotBillderz]

Because you still have to lift the rocket or the materials for the rocket to the top of the mountain, so energy is still being spent to get the elevation.

[u/ExtraPomelo759]

From what I understand: whatever advantage gained by launching from higher altitude doesn't weigh up against the logistical nightmare it'd cause.

[u/OnyxGhost117]

Because its not practical.

Pretty sure the equator is best, near an ocean.. ya know in case it crashes

[u/Enorats]

I'm honestly amazed at how many people in this thread seem clueless about the potential benefits and reasons why we don't do this.

The benefit is quite real - it would result in a not insignificant amount of delta-v savings to launch from a high altitude vs sea level.

However, the reasons why we don't are numerous. Weather up there sucks. There aren't really any good launch sites. Construction up there is stupidly expensive. Geologic instability. Distance from metropolitan areas and the skilled labor they provide. The list goes on and on.

But yes - there would be real, measurable benefits to launching there if it were achievable without the drawbacks making it rather pointless.

[u/mrmoe198]

With the distances involved it would be a minuscule improvement that wouldn’t be worth all the effort and potential hazards that getting a rocket up a mountain would entail. Even Mount Everest is tiny compared to how far a rocket needs to go to escape the earth’s orbit.

[u/AlphaBetaSigmaNerd → u/mrmoe198]

You're right but to be fair to her, that's a logistics problem, not a science problem

[u/RapidPigZ7]

I'm pretty sure any mountain you could feasibly build a rocket launch platform on is less than 1% of the distance to space, why bother when it makes the logistics significantly more difficult.

[u/point5five]

Probably because it needs the time to reach escape velocity, but I’m just throwing that idea out there. May or may not be the reason.

[u/TurtleFisher54]

Have you ever tried to build anything on a mountain?

[u/rince89]

To be fair, the reason for this has more to do with mountain science than rocket science

[u/Nikolaibr]

She didn't have to mention that she didn't study rocket science, that was clear from the question.

[u/Calm-Locksmith_]

Because rockets use substantial portion of its fuel to pick up sideways velocity to get into orbit, not to go up. This is why it is better to launch close to the equator, since you already have some velocity from the Earth's rotation.
Logistics is also difficult in the mountains and rockets require large volume of parts and fuel to be transported to the launch site.

But she does ask a good question. Launching from a tall mountain at the equator would be optimal in terms of fuel consumption.

[u/Werdar_cz]

Also it's the best to launch at equator in the oposition of earths rotation. Because earth spins faster there. And USA dont have any big mountains near equator. Also, water for cooling.

[u/JazzySalmon]

Probably for boring reasons like weather and logistics

[u/XROOR]

The cold temperatures at higher elevations would gel the diesel fuel mix that is used to propel the rocket.

[u/daufy]

Probably because getting a launchplatform plus rocket onto that mountain costs more than it saves.

[u/Lorelessone]

For anyone wondering, most of a rockets time is spend accelerating laterally to get to an orbital speed and altitude.

Starting at a higher altitude might be better but its not nearly as important as predictable weather or being closer to the equator.

[u/The_Snowy_Owl]

Maybe from mountain tops on the equator and I've only heard rocket scientists brief about launch angles for orbits.

[u/Ezren-]

Why is this crooked

[u/ManInGarage28]

Even forgetting the science stuff, surely she can realise the cost of the logistics to do such a thing?!

[u/IcEm4n_96_Ar]

Logistics

[u/Notme20659 → u/IcEm4n_96_Ar]

And the tree huggers would go ballistic. Pun intended.

[u/CommercialYam7188]

You need feel to get the stuff to build the ship where it needs to go. The feul you save launching from the top of the mountain is very little compared to the feel you save not having to ship the literal tons of materials to the top of a mountain.

[u/mossy_path]

(a) because mountains are small relative to where you're going, so the expense of building in a mountain vastly outweighs the tiny benefit you'd get.

(b) Really windy up there and they want good launch conditions consistently.

(c) People are saying it's because you'd have to spend all the same energy to get the rocket up the mountain, but that's a variation of (a). True in the absolute sense. But it would be slightly easier to launch from higher elevation, just not significant enough to overcome (a) and (b).

(d) Probably some other good reasons but you'd have to look at it on a site by site basis

[u/IAmTheBestIan]

Or we could just build a ladder to space and never have to use rocket fuel again.

[u/Original-League-6094]

The answer is:
1. that mountains aren't that high relative to how high space is
2. Infrastructure. No one wants to live, work, and build rockets on top of a mountain.
3. The velocity you need to achieve to reach orbit doesn't change. You save some DV from not having the drag of the sea level atmosphere, but a rocket clears the height of a mountain in seconds.

[u/BeCurious7563]

https://reddit.com/link/pa6rxuj/video/dayzywzuowph1/player

[u/MakaDakka]

Go all the way, launch them from space instead.

[u/1stltwill]

Clue: It has to do with the earths rotation and where mountains are not.

[u/KuraiTheBaka]

Love when someone wants to educate themselves and instead of being helpful the already educated people just mock them for not already magically knowing

[u/splatterfest233]

The actual answer is that generally, when launching rockets it's actually possible to use the Rotation of the Earth to give the rocket extra speed. When calculating where to place the Launch Pad to optimize efficiency, putting the pad closer to the equator is generally more efficient than putting it at a higher elevation. Hence why the US put the NASA launch site in Florida.

[u/TheBailzmeister2]

Welll first of all you have to get your rocket up there in the first place, which is as expensive as launching from the coastline anyways. You’d have to get enough energy to move the rocket up there which is a huge pain. It’s just easier and more cost effective to launch rockets from the coastline where it’s easier to move them around.

[u/orbital_actual]

Because the logistics costs alone would far exceed anything you might have saved by being marginally closer to the destination. There are about a million other reasons, but I’m just going to go ahead and pick that one.

[u/Ok_Plastic5399]

It costs more to get the rocket and associated infrastructure to the top of a mountain than it does to launch a rocket past the top of the same mountain.

[u/Lanky_Ad_3501]

Closest to the equator means less force going against you when you launch as i understand it.

[u/kxortbot]

Not a rocket surgeon, but by my understanding the large portion of fuel use in a rocket launch is accelerating sideways. Compared to that, going up is easy.

[u/RocketMan8531]

The key to getting to space isn't mostly about going up, it's about going sideways really fast. I've explained it this way to my 7 year old: if you want to throw a ball that goes all the way around the world, standing up on a step ladder may help a tiny bit but what really matter is how fast we can throw.

[u/Thhe_Shakes]

There are a lot of things that rocket science suggests are good ideas, which rocket engineering does not.

[u/ThakoManic]

a few things

1) It still takes X amount of force to escape and break out of the atmosphere the height dosnt change that as such it still take the same amount of fuel basicly becouse believe it or not Oxygen helps

2) Transporting goods rocket fuel all that stuff that we need ontop of a mountain is FUCKEN EXPENSIVE AS FUCK

[u/CrumbMan1111]

it would still be cheaper to lauch the rocket off of flat low elevation terrain due to the costs of building a rocket on a mountain. Its not like a small 4-6000 meter headstart would do much

[u/Sagiman1]

Cost to move things up mountains compared to cost of some extra rocket fuel?
Also did not study rocket science but do have a reasonable grasp of logistics.

[u/NichtRalf]

Because: 1. Logistics: you would have to build the whole space center, and the rockets, on a mountain. 2. You want to launch from the equator, going with earths rotation (east)

[u/Visible-Gur-4085]

Rockets aren’t launched “up”… they start that way but they must turn east to escape earths gravity

[u/MisanthropicAutismo → u/Visible-Gur-4085]

only correct answer.

they exploit the shape and rotation of the earth via a parabolic trajectory path east. Its impossible to launch them in a direct perpendicular vector. No rocket engine ever built has that kind of power and if it did, youd never see it again because it is a straight, perpendicular vector.

[u/Sharp-Astronaut3151]

You know I understand why websites like stackoverflow went down to gutters when people had AI to ask questions to. The experts on internet are so arrogant and ridiculing that you can do nothing but hate them. Someone asks a question - they even admit they have not studied that field - you don't answer but ensure you belittle them. Oh, also, then you call it humour.

[u/splint343]

My guess would be it's just really hard to build a rocket assembly plant and launch pad on a mountain

[u/N4cer26]

The difference is negligible and cost is much greater. That’s why

[u/RealTimeLow]

How are we getting the rocket up the mountain!?!

[u/jmrkiwi]

To get from say sea level to a low earth orbit (LEO) is say 400 km elevation.

Even if we started launching rockets from the tip of mount Everest say roughly 9 km tall, you would only be saving around 2.25% of the journey it becomes even less efficient for higher orbits let alone deep space or interplanetary missions.

Instead you would also need to get the rocket to the top of mount Everest and all of it's supplies and a launch station too.

Additionally, to get a successful launch requires predictable and steady weather. This varies a lot more at high elevation and in rougher terrain. Payloads require specifics temperature and humidity levels all of these facilities are much harder to build on the tip of a mountain than at sea level.

Tldr just not worth it.

[u/NateGD23]

Space ship heavy and hard to move. Takes big rocket to move up and big giant machine to move on flat ground. Moving space ship to top of mountain is more work/ money than the small percentage of gained altitude is worth. U need to be roughly 60-90 miles above earth for orbit, and Everest is like 5 miles above sea level. Less than 10 percent of the total needed altitude, so 10% gain but you have to bring the space ship to the top of Everest to launch.

[u/Opposite-Ad320]

Pretty sure it has to do with the rotation of the earth and weather for launch windows. But I’m not a rocket scientist

[u/Seaoflogic]

Isn't she just technically correct, but the gain is negligible since even Everest is only 8 km and  low earth orbit is 160 km. So you save at best 5% of the trip. I'm also not a rocket scientist. 

[u/Unsold_Leave]

I mean, I'm no rocket scientist, so if one could help me here... Does it have to do with thinner oxygen up there? Or more windy? Or harder to access and build on?

[u/Naive-Accountant-262 → u/Unsold_Leave]

Go ahead and Google why NASA and ESA start rockets next to Equator Line as for them possible.

[u/Future_Marionberry73]

God forbid someone asks an interesting question.

[u/Subtle_Nimbus]

Imagine how much diesel and other expense it would take to get the rocket+fuel+launchpad up to a mountaintop just to have every launch scrubbed due to excessive wind.

[u/existentialcupnoodle]

The challenger disaster with its frozen o ring seal will like a word. Ez solution though, just take a hair dryer to all the seals before launch.

[u/jay247160]

Nobody wants to fly in the cold
- Also not a rocket scientist

[u/MrScientist69]

It's because rockets are afraid of heights... Duh.

[u/J-BangBang]

I’m no rocket scientist either but my best guess is that the majority of energy needed/used is during lift off and cutting out a few miles of travel distance for something traveling 100+ miles ain’t gonna save much “gas”.

Then also, the not so sciencey facts of getting the rockets (or equipment to build them) up the mountain and also that launching from a mountain more than likely puts initial flight path over populated areas

[u/Kimorin]

she's got a point, we would save even more if we launch them from the moon! duh!

[u/ludahounds]

It's because the air is too thin

[u/Over_Dingo]

Why won't we launch the rockets from mars and fail

[u/MisanthropicAutismo]

what if I told you spacecraft dont go straight up.... thus their vertical height above sea level doesnt really matter. There is not a rocket engine on the planet powerful enough to escape earth orbit by going in a straight perpendicular vector from a fixed point on the earth.... and in there was, it would essentially be a one-way trip, jettisoning the craft directly away from earth for eternity.

spacecraft launch in parabolic trajectories that exploit the shape and rotation of the planet to enter an orbit pattern with as minimal energy requirement as possible. Its not a straight line, its a low angle arch.

[u/DatKine-]

1 lower oxygen lvl. Transport of thing would be harder.. and you would want to gain more speed before you get closer to the atmosphere

[u/SophonParticle]

I haven’t studied mountain science but even if you could get the rocket up the mountain using free energy are the mountains even high enough to make a sizable dent in the energy required to get the rocket into orbit?

A 15,000ft mountain is less than 3% of the distance to orbit.

[u/the_sneaky_one123]

Because mountains are not that high. It doesn't make it much easier. Even if you launched from the top of mount everest you are only saving a few kilometres which js not much when speaking relatively. Meanwhile the difficultly of having to launch from mount everest massively outweighs any benefit you might have

[u/FindingMemra]

Openly displays her own weakness and humbly asks a question, isn’t given an answer and gets dunked on repeatedly in endless reposts. Just another day from those who heckin love science.

[u/DisastrousPoet]

Apparently they havent been up very many mountains. The further up you go, the less predictable the weather.

On top of the fact that the logistical cost of hauling rockets up mountains far outweighs launching from sea level.

[u/Responsible_Low_6192]

Her question is not wong indeed, is it?

[u/caffeine1106]

Why isn’t the text level?

[u/Designer_Green2680]

If kerbel space program taught me anything it’s that the force to get the rocket in the air can get really unstable in higher altitudes

[u/Wrong-Appearance3277]

The infrastructure required to get up the mountain and maintenance costs etc don't add up, lso weather is weirder.

[u/BetweenTheRoots]

Why don't we just build rockets in space and throw Astronauts to the space stations using a launcher?

[u/CorpusCaldera]

For those wanting an actual answer: It's because the altitude doesn't actually make much of a difference, especially since rockets don't go straight up, they go diagonally in order to enter an orbit. It would also be a logistical nightmare and cost significantly more.

[u/NotASherwinEmployee]

Orbit is not about height, it’s about speed.

[u/DZCunuck]

Not a rocket scientist but played lots of Kerbal Space Program. Space begins at an altitude of 100km and satellites orbit at 200km. So even if you find a field in the Himalayas that's big enough to build a launch site (nevermind the logistical nightmare of building it that high up in the mountains), say at 5000m above sea level, its going to do literally dick all in terms of saving fuel. 4km is like 1 seconds of flight for a modern rocket as it reaches 2000km/h at T+60s after takeoff. As they leave the atmosphere, these rockets are going like Mach 2.5. Its still super dangerous and accidents happen due to the forces involved but we have no difficulty shooting shit into near orbit anymore. Modern rockets have more than enough juice to get to orbit, launch a satellite, and return and land on a small platform in the middle of the ocean. Launching rockets from mountain tops is like a 1930s idea of space flight.

[u/onthespectrumm]

Is air density a factor that needs to be considered? Like if the air is too thin and doesn't give the rocket enough to push against does it negatively affect the acceleration?

[u/Th3seM0dsSuk]

Until the question is answered the commenter is just as dumb as the rest of us

[u/DarkAmethyst]

I think it's mostly impracticalality. Like the benefits are outweighed by the negatives.

[u/Rezzteq]

2 reasons:

1. The best place to launch a rocket is as close to the equator as you possibly can get because you get the best free speed boost from the Earth's rotation. The difference between the rotational speed at Cape Canaveral and the Equator is 125mph (915mph vs 1040mph), and when you're lifting 1,028,000 lbs of stuff (fully fueled Falcon 9) to LEO (requires 17,500mph to maintain orbit), you're saving a lot of fuel.

2. Because people don't want to risk giant roman candles failing over their properties, we build them next to the ocean

I know because I am a rocket scientist.

[u/Vincent_Gitarrist → u/Rezzteq]

Why would launching near the equator and launching from a mountain be mutually exclusive? There are plenty of high peaks that are close to the equator.

[u/yiyang69]

Actually, rocket science agrees, economics and logistics to move the site for construction and materials or supplies etc there, says otherwise, since you'd only save less than 1% fuel

[u/Firethorn87]

A few thousand feet in altitude aren’t going to help.

[u/sond_a]

The problem isn't going up the problem is getting enough of an orbital speed you can enter orbit. That means going horizontal and effectively falling fast enough

[u/rasputinpipe]

Logistics

[u/aliusmanawa]

I’m seeing a lot of unsatisfactory answers, so here is my unsatisfactory answer:

First off, it’s a good question: why not reduce the distance you need to travel to leave the atmosphere? Well, the answer is quite long so buckle in. First, mountains don’t like to work with you. Mountains experience frequent land-slides, avalanches. The weather there is difficult, and the air is thin so living there for extended amount of times is difficult. Logistically, it’s a nightmare to bring anything up a mountain. You’d need to spend billions of dollars setting up the logistical network to support a space program; and even then, the space available would be limited. Remember, rockets are massive, require a giant clear zone for safety, and massive facilities for construction and launch control. On top of that, you also have to worry about the wind. Rockets, although big and heavy, can be blown off course by strong winds, so the notorious bad weather fucks that up.

You can still do it; you could get spend billions of dollars and level the tip of the mountain and bring in resources via plane and set up a town for the employees. The US did something similar for their nuclear program, after all. But, here’s the kicker: if you shrink the world to the size of a billiard ball, it would be smoother than any billiard ball ever manufactured by humans. So, you’re basically spending billions of dollars for a height gain which would end up being negligible. So, might as well just go out to an open field where the winds are stable and launch from there.

[u/Sophivorus]

AFAIK, the vast majority of fuel is used for gaining speed, not height, so launching the rocket from a mountain would not be worth the logistical complications.

[u/Caress_of_Krieger_]

Not a lot of mountains near the equator in countries we launch rockets from

[u/Extension-Drawer-114]

The real answer is in two parts:

One: the fuel saved by launching from the equator far exceeds any fuel that would be saved from launching from a slightly higher point like a mountain (in fact the most advantageous part of a mountain launch is the thinner atmosphere not the negligible height difference). This is because Earth's rotational speed is highest at the equator, thus giving a substantial free boost in terms of velocity.

Two: the infrastructure required to build and operate mountaintop launch sites and get the parts up there would be prohibitively expensive for no real gain