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[-] gandalf_der_12te@discuss.tchncs.de 57 points 1 day ago* (last edited 1 day ago)

If the planet is massive enough, getting to orbit becomes a real challenge because fuel consumption scales roughly exponentially with the mass of a planet (delta-v formula, rocket equation).

This leads to an almost sharp cut-off for the maximum mass that a planet can have so that a rocket which utilizes chemical fuel (e.g. methane+oxygen) can still reach orbit successfully. This maximum mass is roughly 10^26 kg.

For reference: Earth's mass is around 6*10^24 kg.

While other propulsion types exist, such as nuclear + ion drive, these propulsion types are significantly more complicated.


Interestingly, if a planet is too small, it cannot hold an atmosphere. There is a surprisingly sharp cut-off minimum mass for this as well, at roughly 10^21 kg.

[-] grrgyle@slrpnk.net 7 points 20 hours ago

I propose going to the south pole and just letting go??

[-] modus@lemmy.world 31 points 1 day ago

We really are in the Goldilocks Zone, aren't we?

[-] HopeOfTheGunblade 24 points 1 day ago

Well, yes. In the middle of the goldilocks zone that is based on the environment we are adapted to is where you would expect to find us :p

[-] grrgyle@slrpnk.net 2 points 20 hours ago

Anthropic principle ftw

[-] modus@lemmy.world 7 points 1 day ago

Haha fair point.

[-] Techlos@lemmy.dbzer0.com 12 points 1 day ago

If anything, it'd be a bias towards spaceplane designs over straight up rockets. As long as the atmospheric density relative to the gravity supports it, offloading some of the acceleration to high atmospheric flight using ram/scramjets can massively reduce the launch vehicle mass (don't need to carry oxidisers for the flight stage).

That being said, it also would be a bias against high orbits and space exploration in general; safe re-entry is tricky enough on earth.

[-] Windex007@lemmy.world 6 points 1 day ago

I suspect that atmosphere composition makes different options more or less viable.

The difficulty/cost getting to orbit probably also would influence where a space elevator lands in terms of developmental priority.

[-] MissJinx@lemmy.world 2 points 1 day ago

I did not know that. It's because it interferes with gravity? I'm dumb sorry

[-] UPGRAYEDD@lemmy.world 8 points 1 day ago* (last edited 1 day ago)

Not enough gravity, the atmosphere will drift away from the planet with the help of solar winds etc. Too much gravity, and the ammount of fuel you need to leave the plannet weighs more than the rocket the fuel is being used to lift can carry.

Even in our current ships, most of the fuel used to leave orbit is really used to carry the other fuel you need later.

this post was submitted on 13 Apr 2026
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