tl;dr: for a rocket it is waaaay more important to go fast than to go high. and earth rotates very slowly, so going higher doesn't make you much faster.
We are outside the bus, doing a space walk. Next thing we knew a god damn Tesla roadster blaring fucking David Bowie came out of nowhere and hit Arnold and launched him into deep space. We couldn't catch him in time.
In orbit around the equator you are always over the equator. In polar orbit the earth is rotating under your orbit. If the orbital velocity/period is timed right, then over time you fly directly over every part of the world.
iirc correctly it should still be less costly of you start way northern and still start eastwards. you'd get a high inclination and changing inclination is definitly cheaper in space.
I might be wrong and starting directly into 90 degrees is actually the cheaper way, but I can imagine that at least using some momentum from the earth's rotation should be better than actively working against it
Inclination changes are extremely expensive until you get to a very high orbit. An inclination change is changing your direction, so the faster the spacecraft is moving the more expensive it is. Low orbits work by having extremely high speed, so it is consequently extremely expensive to change their inclination once they're launched.
To throw some numbers at it, the delta V for a circular orbit inclination change is 2*v*sin(delta inclination / 2). If you launched East from Kodiak Alaska you'd get into an orbit with a 58 degree inclination, so you'd need to plane change 32 degrees. At a LEO velocity of 7.8 km/s that works out to 4300 m/s of delta V.
By launching due east you'd get a boost to get into LEO of 2*pi*(1/day)*(radius of earth)*cos(58 degrees) = 250 m/s (plus you don't have to spend the few dozen m/s of extra delta V to burn off that eastern motion for a direct polar launch).
There are theoretically some launch points and destination orbits where launching East and doing a plane change makes sense, but they're pretty edge case. For example, from Kodiak if your target orbit was polar and had a radius of about 2 * 109 meters (about 5x the distance to the moon) then the plane change would be so cheap that you may as well launch East. That isn't a particularly popular altitude to launch a satellite to, though. There may be a less extreme scenario where the plane change makes sense--I didn't do the math to find the best case scenario since a more equatorial launch needs a bigger plane change but gets more delta V at launch--but they should all be pretty high orbits like this.
4.7k dV is really extreme and yeah, I didn't think about the LEO speeds needed.
So what's the actual use case here? Launch directly to 90° or rather something like 80° due to the fight against the rotation and then either say "good enough" or correct the last bit of inclination? Or just don't plan with 90° in the first place?
Yes, ideally you launch straight into an orbit that's as close to your end goal as possible, then do some fine tuning when you get there.
The more accurate your launch vehicle is the less fine tuning you have to do. When JWST was launched one of the news stories was that the launch was more accurate than planned so the vehicle would have more fuel left over for station keeping. That was a big deal since that's what will likely determine the lifespan of that telescope.
The desired orbit is generally determined by the mission that the satellite is setting out to do, then from there a launch site is chosen to make that orbit the easiest. Modestly inclined orbits will tend to launch from close to the equator for the free delta V from Earth's rotation, while polar (or nearly polar, e.g. the slightly retrograde sun synchronous orbit) tend to launch more or less due south from sites like Vandenburg or Kodiak.
Where you do have to just launch east and perform a plane change is for uninclined orbits, most notably geostationary orbits. Any orbit you launch into will be inclined by at least as much as your launch latitude, so unless you're launching from exactly the equator you're going to wind up with some inclination to deal with. Fortunately this mostly only matters for GEO and that's a relatively high orbit--orbital speed of "only" 3.1 km/s. If you launched there from Canaveral then you're looking at "only" 1.5 km/s of delta V to come into plane. There also might be a bi-elliptic shenanigan you could pull here (raise apogee far beyond the target, perform the plane change at apogee where speed is virtually zero and plane changes are virtually free while raising perigee to target, then circularize at perigee); I haven't done that math in a long time.
The other big exception to launching straight to your target orbit is when the target orbit is something like a trans-lunar injection or an interplanetary transfer. Here it's technically a tiny bit more efficient to burn straight to the follow-up orbit, but it's lower overall mission risk to launch into a temporary orbit, check that everything still works after launch, then proceed on to the subsequent maneuvers. This can give much wider launch windows than a direct launch to the transfer orbit, lowering risk of bad weather or a launch hiccup derailing the entire mission.
There's also not much land south of the Kodiak Spaceport other than Hawaii and Antarctica to have rocket bits fall on. That's also why most of the US polar launches are from Vandenberg SFB. Polar launches from Cape Canaveral are doable but difficult and restricted. You have to thread needles between islands. Starbase Texas has too much land north and south of it. Starbase Louisiana might be able to do it, but Mexico won't be too happy about it.
No one in their sane mind does any significant plane change maneuvers in low earth orbit. It's ridiculously expensive. If you want to launch to a polar orbit, you launch directly into a polar orbit.
Holy hell. I learn things on Reddit that I never knew I was interested in until I read it on Reddit. Now I have been furiously researching this stuff. Awesome comments.
Because having it quickly wind up over water rather than populated land is a common requirement, and the convenient places you can do this with enough fairly-flat space for a pad, near the equator, are rapidly running out...
So you make a smaller pad for lower orbits that require less speed, farther north/south.
Not all satellites desire an Equatorial orbit (An orbit that follows the equator). There are many other orbital inclinations that may be desired, to reach them it would be more efficient to launch from a more advantageous location on earth. Its more fuel efficient to launch from a location that is slower but closer along your desired orbit rather than to launch from the equator and then perform an extremely expensive correction burn.
The only advantage of launching from a higher latitude is if the desired orbit is retrograde (opposite to the Earth's rotation) where the extra rotational speed at the equator has to be counteracted. Prograde orbits are more common simply because they're cheaper (you get some free delta-V from the Earth's rotation).
But in practice, the ability to use a single launch pad for every orbit invariably outweighs the cost of the extra delta-V for retrograde orbits. A launch pad at high latitudes can't directly put something in an equatorial orbit; it would have to start with an orbit which peaks at the launch latitude then apply a correction at the equator. Whereas an equatorial launch pad can directly launch to any orbit.
It would be more efficient to launch closer to equator, as long at the target orbit has more velocity in the direction of Earth's spin, than the launch site has. Which means pretty much every orbit except near polar and retrograde orbits, because with those you need to cancel out the 465m/s velocity given by earth.
Some rockets need to go into higher inclination orbits, where you'd need to cancel out the launch pad's starting velocity if you launched from the equator.
For certain orbits it can be beneficial. It depends on the inclination, which is the angle of orbit. Some orbits are equatorial, most are angled 40-60° (such that they see different parts of the earth with each orbit), some are polar (such that they get comprehensive coverage over multiple orbits). There are lots of different orbits for different reasons.
I'm pretty sure the Alaskan launch site is better for a polar launch, whereas Florida mainly allows for launches over the Atlantic ocean.
However you can always do a launch and then change inclination on orbit. This is more expensive on fuel, but not all that uncommon, particularly for military missions.
Polar orbits. They're more expensive (in energy terms primarily, but energy costs money) because they don't get the ~1600km "boost" from the Earth's rotation.
However, there is another consideration in here; most of the rocket doesn't make it to space. SpaceX may be able to land their boosters (well, the first stage) Rocketlab does not. This means that there are boosters falling back down to Earth. If they launch over the ocean, it's a lot easier to implement large "no go" areas for the duration of the launch where boosters are predicted to crash back down.
Similar reasons to why Russia has some of the northernmost spaceports in the world. Satellites and payloads of the sort don’t need as much speed, making it better for them to get into polar orbits. Granted, Russia also has some of the northernmost cosmodromes because they in general aren’t very southern, so much so that their southernmost one, Baikonur Cosmodrome isn’t even in Russia, but in Kazakhstan, since it’s decently flat and was in the Soviet Union, which means now they pay millions upon millions to rent it from Kazakhstan, in addition to maintenance and managing the city that houses the staff.
From an AI overview, so take from it what you want:
Rocket Lab uses high-latitude locations like the Pacific Spaceport Complex in Alaska rather than the equator because the destination orbit matters more than equatorial rotational boost. [1, 2]
While launching near the equator gives a free eastward velocity boost (about 1,000 mph) ideal for equatorial or geostationary orbits, it creates a major disadvantage for other paths. [1, 2, 3]
Polar and Sun-Synchronous Orbits
The Inclination Match: A rocket's lowest possible initial orbital inclination matches the latitude of its launch pad. Launching into a polar or near-polar orbit from the equator requires a massive, fuel-heavy plane-change maneuver. [1, 2]
The High-Latitude Advantage: Launching from a high-latitude site like Alaska or New Zealand allows rockets to fly directly into polar or sun-synchronous orbits without wasting fuel fighting Earth's equatorial bulge. [1, 2]
Geography and Trajectory
Safe Flight Paths: High-latitude and coastal pads offer clear trajectories over open ocean waters. This minimizes risk to populated landmasses during initial ascent. [1, 2, 3, 4]
Specific Customer Needs: Many Earth-observation and weather satellites require polar orbits to scan the entire globe as the Earth rotates underneath them. For these missions, high-latitude spaceports provide the most direct and efficient route. [1]
Low Earth orbit is around 400km up (90min orbital period or so). The edge of space is considered to be around 100km up. The atmosphere is pretty thin. If you are sending up a geostationary satellite though, you are comparing, say, Everest (9km) to the orbital distance of 70 000km, that's indeed nothing. The difference in velocity you need to get is very small.
He wasn't talking about the launch having to cover less distance if it was released higher, but how you are technically moving faster with the Earth rotation if you are farther to the center.
So the number is +- 6700 km against the height of the mountain.
maybe the first person didn't fully understand the question but they still provided the answer, intentionally or not. being further away from sea level gives a few km/h in terms of speed...which is really nothing compared to the escape velocity required. good question though.
Also the radius of the earth is 6400km. Another 9km is about 0.1%. So technically you get a little more, but practically the juice ain't worth the squeeze.
(atmospheric density might matter a little more, but I'm pretty sure the rocket scientists of the world would already be doing it if the payoff were 'enough')
You mixed up Earth's atmosphere and Earth's size as a whole, the atmosphere is much thinner. Moreover, at the altitude of Mt. Everest, the atmosphere is around 1/3rd as dense as at the sea level already (hence the breathing problems). This would've made a large difference to the possible nozzle designs/engine efficiency if they were designed for that. So, ignoring logistics(!), it would be more efficient, but it's just not worth the hassle currently. There are more easily accessible mountains in South America that lie on the equator that would be a more realistic site for a spaceport, I think.
The atmosphere is "thinner" when talking about a specific layer of it, to get to space you have to go through every layer of the atmosphere, which is in fact 10,000km.
The atmosphere is 100km, but it's not equally thick everywhere. At the top of Everest, the air density (and pressure) is only one third of the sea-level. Because pressure is directly related to the weight of the air column above you, this means that a rocket launching from Everest only needs to go through one third of the air that a rocket launching from sea level would. Less air to go through, less energy lost to air resistance, less fuel consumed.
Further, because the air is less dense, the dynamic pressure acting on the rocket would be much lower, which means the rocket doesn't have to be as strong to withstand it, so it can be even lighter, resulting in more fuel savings.
However, even with taking all this into account, it's nowhere near worth it.
probably not. based on a different reddit post (great source i know), ground wind and direction are important because it might blow the rocket into the launch structure or affect flight stability. once the rocket reaches a certain height there's not much wind left to affect it. interestingly, rain is usually not too big of an issue because rockets clear clouds so quickly anyways (and rain doesn't affect the rocket which is sitting in the rain before launch)
i wasn't able to get as much info on this. it seems like a desert would be ideal because they have less wind? however a more practical aspect is it needs to be a coastal region because no one wants to launch rockets over a populated area. so regardless of biome, the location would need to have a large body of water to the east and ideally have low winds.
Wait to the east? Isnt that the direction the earth is spinning towards?
I ask because sun rises in the east. And, if the rocket leaves the surface the land would be spinning eastward faster than the rocket. So rocket would be going in a more westward direction if shot straight up, right?
Or do they "aim" the rocket eastward to begin with, to assist in velocity?
Edit; or is this a centripetal/inertia kindof thing?
because the earth rotates towards the east, everything has some momentum in that same direction. at the equator the earth's rotational speed is the highest so you get the biggest bosot. so if you launch a rocket at the equator, the earth is effectively flinging you. the only thing that really matters is going fast enough.
And if you are a company or a country who cares about people, you need to have a see or a desert on the east of your launching pad (in case of failure it can rain fire on thr people just like when it happened in China)
The earth’s radius is almost 4000 miles. Even if you had a 40 mile tall mountain (fyi, Everest is less than 6 miles) that would only be 1% further out than a launch at sea level. The rotational speed difference from an actual mountain near the equator would be a rounding error.
The thing that most humans have trouble grasping (this is no shade on you, yourself, it's a whole human society sort of thing) is that Mountains are not all that tall, on the scale of the solar system.
The amount of height you gain from launching at the top of a mountain is relatively negligible compared to what you've got to attain.
In the very most literal technical sense, and ignoring all set-up costs, yes a Mountain near the equator would be better than sea level. Similarly, an air-based launch (i.e. a plane carrying a launchpad that the space rocket takes off from) achieves about the same benefits.
Mt Everest, tallest we can find, is around 9km tall (over sea level).
Low Earth Orbit, the target of most space journeys, is at about 1,000km.
In nearly every situation, it just isn't worth the hassle to do anything other than build a robust base near to the equator on flat land (for ground logistics/transportation reasons).
The increase in speed from rotation would be effectively none. What you would gain, and i haven't seen anyonemention this, is that you would avoid the thickest parts of the atmosphere, reducing loss from air resistance, and, depending on your rocket engine design, could gain more velocity from the same amount of fuel because of the lower atmospheric pressure.
The mountain has well maintained roads to get up to the launch point
The launch point has the space to build out all the various support equipment for a launch--hangars, bunkers, fuel tanks, water tanks, support towers, etc.
The mountain is somewhere politically friendly to the launching country
The weather on the mountain is consistently conducive to launching rockets
The mountain is located West of an area that won't complain if you sometimes drop boosters on them
Those extra caveats are more important than a bit of bonus altitude at launch, so they tend to be satisfied and "mountain" gets cut. Even "equatorial" is often cut in favor of convenience of access and political friendliness.
However, even better than a mountain would be to launch from above the mountain, and with a running start. That's the idea behind the Pegasus launch system, a relatively small payload rocket that is launched from a L-1011 during flight (or previously from a B-52). This concept can only handle payloads that a plane can carry, which leads to the development of some true monsters like the Scaled Composites 351 Stratolaunch, a plane that is by various metrics the largest in the world.
If you ignore the difficulty and safety factors, yes, mountains near the equator would be the best spot on Earth. The highest equator peaks also stick out "into space" more than Mt. Everest because of the way the Earth bulges at the equator.
It is possibly marginally better on paper but then you have to deal with the practicalities of hauling your rocket up a mountain, getting it staged up there, and then all of the energy requirements to power the thing, maintenance, etc.
At the end of the day, the equations and science tells you that you need your rocket to fly at a delta v of around 9.4 km/s or 21000 mph to get to the ISS, about 400km up in space.
For reference, Everest is like around 9 km in height compared to sea level. So the difference is not very much when we are talking about these velocities.
Not just because of that. It's because there's a coastline there - rockets want to launch over water - and because it's the only reasonable way to get to lower inclination orbits. Low inclination orbits are better to go to things like geostationary , to the moon, to the plane of the ecliptic in the solar system.
They pretty much just launch sounding rockets. Nothing to orbit. Although they could, depending on the orbit they are trying to use and the fuel they have available.
This and it being a beautiful tropical destination led to the mafia using that area as a preferred place to hide from the law. Fast forward to today and the area is full of Italians on beach vacations.
I always thought it was to be closer to the water landings and for rockets to possibly land in the ocean if the launch goes bad. This also makes sense cool
I mean it's literally not in Brownsville. The area was originally named Boca Chica. Saying they launch from Brownsville is like saying Launches from Kennedy are launching from Titusville.
Every country that launches to space does so from a site that is as close to the equator as their territory allows. But there are two reasons for it:
The slight boost you get from the earth spinning faster at the equator
The fact that every orbit goes over the equator, so you can launch into any orbit you want. Most useful orbits are the ones close to the equator (have a low inclination), because of the first reason. Far from the equator, you can only launch into an orbit that has an inclination equal to or higher than your lattitude. You technically can change orbits in-flight, but that is very expensive in terms of fuel.
This is mainly a problem for Russia. The ISS was already bult in a higher orbit to accommodate launching from Baikonur, but that is in Kazakhstan. Everything else is too far north to reach the ISS's orbit without major course corrections.
No, I don't think that people in French Guiana could do things like legalize cannabis even though it's illegal in France as a whole, but that's literally what Alaska can do and has done and is doing hahah.
Can you explain why you think French Guiana is more like Alaska or a US state?
More like a US state than an overseas collectivity, territory, or colony.
I'm not addressing the differences between a federation and the french unitary republic. I'm pointing out that french guiana and alaska are both in the category of "normal, standard, national soil."
The above comment relating French Guiana to the 100 departments is a useless descriptor for anyone unfamiliar with departments. The analogy for Alaska will be a useful one for contextualizing French Guiana for the hundreds of millions in the anglophone world who make up the majority of reddit users.
What do you mean? I'm confused what point you're actually trying to make?
They are part of France.
Washington DC is part of the US.
People in Washington DC do not get a voting representative in either House of Congress. People in Washington DC do get to vote for the President of the United States.
People in Washington DC can also do things like legalized marijuana even if the federal government hasn't.
People in French Guiana do get voting representation, but do not even have the level of autonomy that places like Washington DC seem to, so it just seems like it's not a direct one-to-one thing that we can compare as simply as that.
Basically it's a tough example because France is already so much more of a centralized type of federal government compared to the US government that it's kind of tough because the French don't even have anything close to the level of autonomy of our states so of course you can't have something that's halfway in between that and a more centralized control which is sort of the position a lot of American territories and protectorates and such are in.
And we have different levels because for example while people living in Washington DC can vote for the US president, people living in American Samoa or whatever cannot, actually they can vote, they just don't have any or lectures that they are able to send to the electoral college so it's literally just about a show of opinion in those areas because they literally don't have binding elections for the US president as they don't send electors out. Whereas Washington DC can have no more delegates than the state with the smallest number of delegates, which will probably always be three as that's the minimum and there will probably always be at least one state that doesn't have enough people to get more than one representative to join in the House of Representatives.
But at the same time, those areas still have more rights than a lot of people in any part of France do in the sense that they have more autonomy so they can do things like legalize gay marriage or something even if it's not federally recognized they are almost given the level of autonomy of states when it comes to the local control of their areas, but essentially just with no Force because they basically just have no standing if they ever go to court in the federal government wants them to do something a different way lol.
Florida was connected to the nation's rail network, so getting material there was relatively cheap, vs building the launch center in say Puerto Rico (about 700 miles south of Cape Canaveral) where transportation costs would have been higher.
Also, around the time the space program started, there was this whole thing about rockets/missiles on ships south of Florida, and a lot of people got pretty excited. So, no spacecraft put on ships to Puerto Rico.
Yea once things were settled in Florida, that was that. The savings of moving closer to the equator would be eclipsed by the logistical costs of moving all that shit and uprooting everyone's lives.
Yes. Countries already do that. It is one reason the US launches from Florida, Texas and Southern California, and Russia launches from Kazakhstan.
This actually makes Russia's early lead in the space race all the more impressive.
Starting at a higher altitude also helps, but you must transport the rocket to that altitude or assemble it there and both are difficult. Launching from the coast lets you use barges to transport rocket parts. If you don't have access to waterway, then a railroad is your next best bet and running railroad tracks to the tops of mountains is not ideal.
Finally, some rocket launches fail. If you start at the coast you can launch over an ocean so if things go wrong the rocket crashes into the Ocean rather than hitting a populated area.
Can't imagine that top of mountain is actually better logistically. You save some rocket fuel since you have less air drag to go through, but I can't imagine those cost savinga make it worth all the troubles and costs you'll have setting up and launching from there.
Fun fact regarding the russian lead. They were more reliant on salvaged nazi germany tech and scientists them americans and von Braun (US has intresting rocket program pre 2 world war). Soviets cleansing themself of it while US got the whole nazis invented US space program is due to von Braun being public head of program is funny
This actually makes Russia's early lead in the space race all the more impressive.
Especially the moon and interplanetary missions. You can launch into the ecliptic plane from Cape Canaveral, but Baikonur is too far from the equator.
If you ever play Kerbal Space Program with the realistic solar system mod, you'll find it nearly impossible to replicate Luna 1. It launched towards the north pole, and relied on precise timing of the launch to hit to the moon (which it didn't because of a control failure). On the other hand, the american probes were able to launch into the plane of the moon's orbit, which is easy to do.
They do that but it's not because it's where the spin is fastest it's because the closer you get to equator the less you need to burn after getting to orbit to turn it equatorial
And another fun fact: because it’s spinning, the earth isn’t a sphere. Centrifugal forces make the earth thicker at the equator.
Height is typically specified on sea level but for leaving earth it doesn’t matter, distance from center mass matters. And at the equator you’re already further away than any mountain would ever bring you.
Precisely! You'll notice countries further from the equator will build launch sites as close to the equator as possible or use ones in othet countries.
In the game Terra Invicta where you have you bring the fight against the aliens to the solar system you get more boost near the equator for that reason as the game leans into hard scifi.
Its also why the Soviets had their spaceport in what is now Kazakhstan
Do you know why the main US launch pads have traditionally been in Florida? Because it's as far south as you can get in the continental US, and also has oceans to the east (they launch in the direction of the earth's rotation, and want to drop their tanks over the ocean so they don't hit anyone) They considered building them in Hawaii, but shipping everything to the Pacific and building it on an island was considered too difficult.
SpaceX built it's pads in Brownsville for the same reason, as far south as they could get in Texas, and also with water to the east.
Building right on the equator would be best, preferably on an eastern coast (Brazil, Somalia and Indonesia all have that intersection), but no equatorial nation has a space program.
Yes. Also launching from the equator allows for more possible orbits. So countries tend to build their space launching facilities as close to equator as possible.
Just to add: the earth is spinning roughly 1500 km/hr at the latitude of Florida, and a maximum of 1650-ish at the equator. Escape velocity is 40,270 km/h, so yes, you get a speed boost, but not enough to justify moving away from all the infrastructure benefits of launching from Florida.
The mountain thing is interesting too though. Rockets are designed to have maximum efficiency at a set atmospheric pressure, and the farther they are from that, the worse they do. Starting on a mountain with thinner air means you can pick a lower optimal pressure and be more efficient in both space and at launch. Again though, the savings is pretty minimal compared to all the other costs associated with building a rocket.
This reminds me of a great YT I just saw about how it is ‘easier’ (relative term for lack of a better alternative) for space flight in the same plane as our solar system system, but extremely difficult and resource exhaustive to go up, I.e. we can travel on the xy plane of our solar system with the help of gravity, but flying in the z direction is near impossible.
Not just theoretically. This is current practice! The faster movement of the Earth’s surface nearer to the equator is “free energy” as far as a spacecraft is concerned. Also the surface is moving toward the East, so rockets are generally launched eastward to take advantage of their preexisting velocity. Pretty neat.
It's not (only?) for the spin thing tho, but mostly because there is less gravity at the equator than the rest of the globe, because the earth isn't round (NO IT'S NOT FLAT EITHER) but more of an oval-ish shaped, so there is more distance between the surface and the core at the equator than you would have at the south and north pole.
And thus, since the farther away from the core, less gravity, and less gravity means less fuel required to achieve lift off and reach space.
Source : What I remember from my middle school physics and geography classes (I'm 34 so it was a couple decades ago). Gotta love living in a country that had, and still have, a department of education.
Yes it saves fuel to launch near the equator and orbit in the same direction as the earth. Retrograde orbits in the opposite direction of earth's rotation consume
15% to 30% more fue
You would think that, but there is more gravitational pull there that equals it out. That is why you weigh the same whether you are at the equator or the north pole.
Anything within 45 degrees of the equator is generally considered good enough, because the radius of the circle formed by 45 degrees latitude is ~71% of the equator's radius (sin 45°), and you get diminishing returns as you head closer to the equator. I believe it's also harder to achieve a polar orbit from the equator.
Yes but countries with the ecconomy to launch rockets are rarely equatorial, and many other issues are generally taken into account, such as existing hardware, or national security concerns for government payloads
There were projects to launch at the equator by launching at sea (see Sealaunch and its use of Zenit 3 rockets) and ESA does it mainly because france still has a bit of south america
Vandenburg and Capr Carnaveral are located about as far south as one can get without being in a major population center in the US, while still launching in a direction that has the rockets drop stages over water
Plesetsk is the major outlier, located far up north in Arkhangelsk, though from my understanding it (and Vostochnyy) mainly serve russian military payloads launched into polar orbits, which dont benefit from the earths rotational bonus, and its location wasn't chosen for space launches anyway, as it was originally planned for launching R7 missiles towards the US, though the R7 never had much a career as a missile, and has mostly been used to launch satilites
Baikanour is again pretty far south by Soviet standards, but also it was originally a missile testing range, so yet again more a cost savings for having the R7 hardware already in place, as well as for various other missiles
Wenchang in Hainan is very close to the equator, and is nowadays becoming fairly important, as no other launch sites got the hardware to launch Long march 5 and 7
Taiyuan, Xichang, and Jiuquan are all located very far inland, in sparsely populated areas, and this generally is very helpful if you want to limit people from getting near your classified launches, though Xichang does suffer from having people living down-range, which is generally not ideal, hence why it doesn't get new launch hardware, and is relegated only to older long march 2, 3, and 4
Yes the equator is best, technically the furthest point from the center of the earth is Mount Chimborazo in Ecuador, it is 2km further from the center of the earth than Everest.
There is a book by Andy Weir called Artemis, they have a pretty substantial settlement on the moon, Kenya becomes a corporate powerhouse specifically because it is located on the equator.
It also depends on the inclination you wish to launch to, if you wish to have Geostationary (where you orbital period is the same as an earth day and your satellite stays in the same spot in the sky) you need to launch to an equatorial orbit. This can be done most efficiently when starting along the equator.
Yes, but you're also generally after a specific orbit. If you launch from the equator, but then need to move to the right orbit, that can easily outweigh the savings of an equatorial launch.
Yes. That's why most major rocket launch sites in the US are in the south, in Florida, Texas, Southern California ect. The closer to the equator you get the more fuel efficient it is to launch shit.
Not theoretically, that’s a real concern when launching a rocket.. that’s why most launches the European Union does are from French Guyana, a territory of France near the equator.. also why NASA always uses Souther states like Florida
There used to bea company called Sealaunch that did just this. They put their rockets on a floating platform (converted from an oil rig), and sailed it down to the equator in the Pacific, and launched from there for efficiency.
Yes which is why the biggest space port in the US is in Florida we have others like vandenburg SFB and wallops Island but their usually used for higher inclination orbits
Yes, but near the equator is good enough. The additional gain you get from being near the equator, to actually at the equator, is minimal.
Plus, the closer you get to the equator, the Earth's spin thickens the atmosphere a bit. This extra bit of thickening is why climbing high mountains like Kilimanjaro and Everest is even doable. If these mountains were located in Antarctica, the partial pressure of oxygen would be so low they likely wouldn't be climbable.
I've heard that it depends on your rockets motion relative to the earth, and if your rocket is travelling in a prograde or retrograde orbit. And that the west fires rockets in, I think, retrograde and thats what they fire from as close to the equator as possible.
However, the Russians who have no access to equatorial waters fire the other way (whichever that happens to be) so they can do it with in their borders.
Can anyone confirm this? I can't remember the source.
This is why most rocket start Centers are as close as possible. USA launches in Florida (most southern point),
Europe in French Guyana (South America), and Russia in Kasachstan (also more South).
It turns out an equatorial orbit isnt as useful and being able to launch stuff from mainland US (or USSR when baikonur was built) makes things a lot easier.
Also, Earth is an oblate spheroid, and bulges at the equator. In fact, due to this bulge, places along the equator are at higher elevation. So you get both rotational speed and height.
That's what they actually do.. not at the equator level, but very close ( probabilly there are other factors at play, like infrastructure near the base, being near an ocean, in case anything goes wrong,stuff like that)
This is true and the reason that fictional space sports are placed by the equator in various stories, like Mombassa being a major space port in the Halo series. Also helpful to be on an east coast of a country due to falling debris and whatnot I think.
the equator is also good because if you're launching a geostationary satellite (one that has the same orbital period as Earth's rotation) you don't need to change your inclination as much (i.e. how tilted your orbit is from the equatorial plane).
if it's orbit is perfectly equatorial the satellite appears to sit above the same point on Earth's equator, so antennae and dishes can point directly at it and never have to adjust
if its orbit is tilted / inclined then from Earth's surface the satellite would appear to drift up and down in the sky messing up alignment to it
also if you're launching a probe to another planet or to a Lagrange point it's also handy to not have to adjust your inclination much, and the equator is only ~23° tilted from the plane of the solar system so launching from there means you're at least pretty close (and if you time it right and aim your rocket correctly you could launch at the time of day where the equator intersects the solar system plane and not have to change inclination at all)
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u/Icy_Concern_9804 10d ago
tl;dr: for a rocket it is waaaay more important to go fast than to go high. and earth rotates very slowly, so going higher doesn't make you much faster.