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.
You’re sort of right. The change in distance from the surface is insignificant, but a spacecraft orbiting a bigger planet has to travel further with each orbit so its speed must be faster to avoid falling out of orbit, even if the gravitational acceleration at its orbital height is the same.
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.
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.
You’re sort of right. The change in distance from the surface is insignificant, but a spacecraft orbiting a bigger planet has to travel further with each orbit so its speed must be faster to avoid falling out of orbit, even if the gravitational acceleration at its orbital height is the same.
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
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
Wikipedia says
energy = GMm/r.if
g=GM/r²thenenergy = mgr, proportional to r given g is constant.apologies
My previous comment was wrong, I derivated while integrating.
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.