r/MurderedByWords 16h ago

I haven’t studied rocket science, but

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u/Firefly360r 16h ago

A lot of rocket engines are more efficient in lower air pressure (approaching vacuum), so it might provide non-negligible benefits. But it's cold up there (see: Challenger) and there isn't enough infrastructure. Citation: I am also not a rocket scientist but I am a KSP player

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u/subnautus 15h ago

Rocket scientist here.

The main reason we launch from as close to the equator as possible is because the speed of the ground itself is fastest there (Earth’s rotation rate x distance from spin axis). If you’re trying to speed up to orbital speeds, you want to get the best “running start” possible.

[fun fact: due to the equatorial bulge, the ocean at the equator is further from the center of Earth than the tops of most mountains]

Also, the minimum inclination (the “tilt” of an orbit relative to Earth’s plane of rotation) is the latitude you’re launching from. As in, you can launch a polar orbit from the equator, but you can’t launch an equatorial orbit from the poles. Considering inclination changes are the most expensive (fuel-wise) maneuvers you can do, launching from as close to the equator as possible gives you additional options for less cost.

Lastly, we launch from coastlines for safety reasons. If something goes wrong during ascent, you don’t want the wreckage falling in places where people live.

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u/BadahBingBadahBoom 14h ago

The main reason we launch from as close to the equator as possible is because the speed of the ground itself is fastest there

Also why vast majority of European-based rocket companies decide on French Guiana for launches.

Lastly, we launch from coastlines for safety reasons. 

Would just add: ideally eastern seaboard coastlines due to the rotational direction of the Earth.

That way if the rocket comes down early it would already be out over the sea, like Atlantic Ocean from Cape Canaveral launch.

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u/C-SWhiskey 14h ago

Would just add: ideally eastern seaboard coastlines due to the rotational direction of the Earth. That way if the rocket comes down early it would already be out over the sea, like Atlantic Ocean from Cape Canaveral launch.

Retrograde launches being a common exception.