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Comment by austinl | Hacker News Reader

I had a similar experience when playing Kerbal for the first time in high school. I thought that NASA got to the moon by simply thrusting in a straight line from Earth in a way that would intersect with the moon's orbit and boy was I wrong!

But now I've found that most people I talk to about this — that also weren't alive during the space race where this was regularly explained on television — have the same naive idea that you can get to the moon by going straight up at it with the right timing.

Instead, you learn that you need to enter orbit and burn prograde at your apoapsis, burn retrograde at the moon's periapsis, etc. — really fascinating and complex stuff! If the curriculum would've allowed it, I feel like I could've spent a whole semester playing and learning from KSP — these kind of games are truly the top of "games for learning" genre.

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Yes, the key here is to understand that you are not exactly flying, but always falling towards something, and you need to change the trajectory of your fall to get anywhere.

So space flight is much closer to sky diving than to air flight.

That's actually the easiest way to get to the Mun in my opinion. No need to plan anything anything just shoot straight up. If you don't get an orbital encounter initially just keep shooting up until you do, it'll happen many times before you reach Kerbin Escape velocity. No need to time anything or plan certain maneuvers.

Basically shoot upwards until you get an encounter, speed up until it auto slows you down near the Mun, then kill velocity to fall in and land.

Grossly and hilariously inefficient but actually easier to perform than the "correct" way (and typically faster in player-time).

That is only possible if you have engines and fuel capable of sustaining a powered flight. We puny humans so far don't have it.

You don't need to sustain thrust the entire time you just need to reach a significant portion of escape velocity energy early in your launch (which is what most launches need anyways just this time you need slightly more energy than the efficient way). This is not something we have trouble doing, for reference we launched New Horizons directly into above escape velocity speed with an Atlas V rocket. The only reason we haven't done that kind of launch to the moon in real life is it's far cheaper and more efficient to do that "normally" not because we couldn't.

Yeah! This was another great realization from KSP — figuring out that the naive way is possible, but the delta V required to do it is absurd.

Here's a video of a KSP speed-run to the Mun and back in 2 hours using this method (with 10K m/s total delta V — I think Jeb takes 34Gs at some point, which is about 5-10x what normal astronauts feel): https://youtu.be/0dx7ScJSAwo

Nah the easiest way is just to get in low kerbin orbit, timewarp until you see the mun come over the horizon, then burn prograde. No manouver nodes necessary.

I love KSP. No other videogame has given me such a sense of Pride and Accomplishment™.

I was once asked to describe KSP and the best answer I could come up with is: "It's a game about speeding up and slowing down".

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