The really stupid thing is that honest, humble questions are the ones that drive useful discoveries. Thirty years in technology taught me that the right question, at the right time, is what makes the world go round.
Its possible that the rest of the answer is cut off.
That said, it's quite funny how ridiculous it is with a little thought.
Highest mountain in the world is ~10km above sea level. The start of space is a bit of a tumultuous topic, 100km being a generally accepted limit.
But that's not exactly where rockets go.
The closest satellite to earth, which is the closest reasonable distance for a space boung rocket to go, orbits at ~400km.
So its decreasing your distance by 2.5%, which isn't nothing, but it's not much.
But my god, the logistics are ridiculous. Getting the stuff there safely, setting up a secure, sturdy launch pad and all the required support facilitie, having a clear view of the launch pad from a safe distance, ensuring weather conditions, it's just so absurdly difficult.
It's not a silly question at all, and it would meaningfully reduce the fuel needed to orbit (which means larger payloads). It barely matters that you'd be a little closer to your final orbital heught, but you didn't mention the three most important benefits that you'd get by launching from the top of a mountain:
Less drag. The atmosphere is much denser and draggier near sea level than on a mountain. Everest's atmosphere is only 35% of sea level.
Earlier gravity roll. Starting higher would make it possible to get the rocket rolled over and firing horizontally much earlier in its flight. This means less energy is wasted fighting gravity. I suspect that this would be the biggest benefit, depending on the exact trajectory.
Better rocket engine performance. Basically all rockets are more energy efficient in a vacuum than in an atmosphere. Starting in 35% as much atmosphere would give a higher specific impulse. You'd probably get 1-2% better ISP over the course of the launch.
The logistics would be insane, which is the actual answer for why mountains aren't used. They would absolutely be significantly more efficient launching points, otherwise.
Scrolled way to far down for that answer. It really isnt a dumb question and rocket scientist thought about it. Its just not worth the logistic hassle.
It's also genuinely a good question and is correct. Launching rockets from higher altitudes/elevation is genuinely more efficient, it's just negligible for the most part. The added efficiency comes from the ratio of the pressure in the engine bell and the pressure of the external atmosphere where the rocket is flying. This has an impact on what's called specific impulse (Isp). Specific impulse, without going into too much detail, is essentially the MPG of a rocket engine and it's propellant. It's the way rocket scientists measure the efficiency of a rocket engine/propellant and is denoted in units of seconds.
Launching from a higher altitude/elevation does increase the Isp of an engine as the ratio of pressures approaches the pressure in the engine bell as the pressure outside approaches 0 or a vacuum. This has a corresponding increase on the Isp closing in on its theoretical maximum for its corresponding fuel/oxidizer mixture.
Lastly, we've launched small satellites from planes for this very reason (mostly flexibility in launch site). It's just not economically beneficial as the logistics negate most of the benefits of launching from higher elevation/altitude.
Other people have already gone into the whole launching closer to the equator argument which ironically ignores the actual question again so I'm not gonna go into it, but in short, it's a good question, and a theoretically sound one that is technically correct. There's just other things at play.
You should use a bit of your thinking skills to figure out why your take is bad. I won't tell you though because I need you to figure it out yourself. Sorry.
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u/Otherwise_Tomato5552 4d ago
I dislike when people answer this way. It’s a genuine, humble question.
No need to be mean