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submitted 3 months ago by fossilesque@mander.xyz to c/science_memes@mander.xyz

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[-] expr@piefed.social 9 points 3 months ago

I assume it's not just about the gravity, but also the much larger radius of the planet would mean much larger distance from the surface, and thus much more fuel needed.

[-] potatopotato@sh.itjust.works 20 points 3 months ago* (last edited 3 months ago)

That's not how.......what???

F = G * (m1 * m2) / r^2

Note that radius is both squared and the dividing term. More distance = less gravity

[-] lemmyman@lemmy.world 10 points 3 months ago* (last edited 3 months ago)

Escape velocity does scale with (square root of) radius so its not a dumb thought.

And I'm not a rocket surgeon but I could imagine earth rockets might be operating near some physical limits that make a 50% increase (or whatever) infeasible.

https://en.wikipedia.org/wiki/Escape_velocity

[-] Lojcs@piefed.social 4 points 3 months ago* (last edited 3 months ago)

Wikipedia says energy = GMm/r.

if g=GM/r² then energy = mgr, proportional to r given g is constant.

apologies

My previous comment was wrong, I derivated while integrating.

[-] expr@piefed.social 2 points 3 months ago

I stated an assumption and was contributing to the conversation. Even if that assumption is incorrect, there's no need to be a dick about it.

It seems like a larger atmosphere would result in a longer duration exposed to atmospheric drag, thus requiring more fuel to overcome it.

[-] turdas@suppo.fi 7 points 3 months ago

That's, uh, not really how that works. A taller atmosphere would mean you have to go through more of it, but unless it's not a terrestrial then the atmosphere won't be that much taller.

If it is a non-terrestrial planet, it's unlikely anyone would be building rockets on there to begin with.