[captainmuon]

Perhaps "slow" ascent would be a option, i.e. not reaching escape velocity but just steadily ascending until you are far enough away that gravity is lower. I know here on earth it is far more inefficient, which is why you always go for "ballistic" trajectories where you gain enough velocity that inertia carries you on.

Maybe there is something you could "ratchet" against? Thrust a bit upward and have something prevent you from falling back down. Maybe the denser atmosphere would provide an option. You could deploy large sails as intermediate launch pads in the atmosphere for example.

[sdenton4]

I once had a fun week playing Kerbal Space Program building solar-powered quadcopter launch platforms...

Basically a quadcopter which is mostly a big platform with a rocket payload in the middle. The quadcopter slowly ascends to the highest feasible altitude, bypassing all of the worst of the air resistance, and greatly reducing the delta v needed to get into orbit as a result.

This was mainly helping with the atmospheric drag problem, though; you would presumably need a lot of atmosphere to get far enough from the planet to help with the increased need for horizontal speed with a super massive planet.

Oh hey I found an old screenshot: https://imgur.io/zq8iyV0?r

[M_bara]

Not a rocket scientist or even a physicist.. but if i remember right, the bulk of your energy in a rocket is expended on your horizontal speed not the height gain. I came across this when I was looking up if it made sense to launch a rocket from an equatorial mountain like Kilimanjaro (6000m asl)

[marcosdumay]

Keep in mind that KSP happens in "easy mode" where all of the atmospheric drag, gravity pulling, and orbital speed are smaller, but they are smaller by completely non-proportional amounts.

Last time I looked, there was a mod that made Kerbin like Earth. I suggest you try it.

[mapmap]

Were you able to land the quadcopter part and recover the cost?

[sdenton4]

Sadly, once you lose focus on a craft in atmosphere it is lost. So shortly after you start piloting the launched probe, the quadcopter gets garbage collected by Kerbin's atmosphere.

[MostlyStable]

My understanding was that (at least for the earth) the strength of gravity is nearly identical at the top of the atmosphere as it is at the surface. So I think that doing this would only benefit you in the sense that launching from the top of the atmosphere means you don't have to push through the atmosphere and it's associated drag, but you are still going to need nearly the same Delta V to make orbit.

But I am very far from an expert (not even a Kerbal player) so happy to be corrected if I'm wrong.

[dr_orpheus]

Yes and no. So the slow/efficient acceleration is realized today with electric propulsion [0] which is very efficient in terms of fuel consumption because it accelerates the particles to such high speeds. But, it is very low thrust so it is something that is on for days/weeks/months at a time versus the small amount of time that chemical rockets are on. Because it's so low thrust though its not something that will actually generate enough acceleration to get you off the ground in the first place. You will still need a high thrust device (i.e. rocket or something more exotic like SpinLaunch) to get you off the ground and in to a low orbit. So while you wouldn't have to reach escape velocity (11.2 km/s on Earth) you still need to get to a very large fraction of that (6-7 km/s for low-earth orbiting satellites).

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

[1970-01-01]

As gravity increases, buoyancy also increases. A high-g civilization with access to hydrogen would be able to float to the top of their atmosphere, and then proceed to launch into space.

[mynegation]

Not a physicist but I thought the main problem is not getting high, but getting fast in the “horizontal” dimension to balance out high gravity and stay in orbit.

[Tuna-Fish]

This really wouldn't help as much as you'd think. For a high-gravity planet, the atmosphere is mostly a trivial problem compared to gravity, and the gravity at the top of the atmosphere would be barely lower than it is on the surface.

A much more realistic and useful option is to just go air-breathing nuclear, and use the atmosphere for reaction mass.

[friend_and_foe]

The gravity from earth at the ISS is 9/10ths the gravity at the surface. The curve for decrease of force is not that curvaceous, to negate the gravity from earth requires significantly further distance than you think.