Gas Giant Floating

[Highrs]

Is there any consideration of permanent floating outposts on Jool and other gas giants in KSP 2? Something that doesn't explode when you look away or accelerate time, something doable in vanilla. Possibly with refueling and refining facilities and a landing pad that can take more than a sneeze.

[mcwaffles2003]

Are you talking about in atmosphere? If so, no that wouldn't work. If you mean in orbit, then yes. Have you seen any of the trailers?

[Xd the great]

4 hours ago, Highrs said:

Is there any consideration of permanent floating outposts on Jool and other gas giants in KSP 2? Something that doesn't explode when you look away or accelerate time, something doable in vanilla. Possibly with refueling and refining facilities and a landing pad that can take more than a sneeze.

I suggest watching Danny2462's video.

They explain why Jool floating outposts are a bad idea.

[Guest]

6 minutes ago, Xd the great said:

I suggest watching Danny2462's video.

Link?

I would love floating Jool outposts and am sad if somebody's discovered it's a bad idea.

2 hours ago, mcwaffles2003 said:

Are you talking about in atmosphere? If so, no that wouldn't work.

Why not?

[Xd the great]

37 minutes ago, Brikoleur said:

Link?

I would love floating Jool outposts and am sad if somebody's discovered it's a bad idea.

His encounters will Jool's atmosphere are, well, interesting.

I would be happy to have hot balloons, but I think the bugs will be unbearable.

[Guest]

1 minute ago, Xd the great said:

I would be happy to have hot balloons, but I think the bugs will be unbearable.

We're talking about KSP2 here. I have no doubt whatsoever that if they want to make balloon bases feasible, they can do it.

I have no doubt it would be hard to mod them into KSP1, what with the physics bubble, auto-cleanup of craft that are in the atmosphere and so on.

[Bartybum]

Are floating bases in gas giants even possible in real life? Would the pressures and temperatures not be too high for current material capabilities?

[breakthesystem]

7 minutes ago, Bartybum said:

Are floating bases in gas giants even possible in real life? Would the pressures and temperatures not be too high for current material capabilities?

I assume the pressure slowly builds up as you go deeper, so pressure-wise, there should be a certain height that has the exact same pressure as Kerbin at sea level for example. Similar things have been proposed on Venus, where you also get high atmospheric pressure further down on the ground. (Floating Colonies on Venus)

[Guest]

1 hour ago, Bartybum said:

Are floating bases in gas giants even possible in real life? Would the pressures and temperatures not be too high for current material capabilities?

Pressure and temperature would not be a problem. You'd want to use a hot-air balloon because the atmosphere is 90% hydrogen. The volume, temperature, and mass determine the altitude at which it floats. You could easily make one that floats at 1 atm pressure, with whatever temperature is at that altitude. 

According to this graph (from Wikimedia), the temperature in Jupiter's atmosphere at 100 kPa (~1 atm) is about 180 K. That's on the chilly side, so if you prefer a more congenial 300 K, you'll have to go down where the pressure is about 1 MPa (10 atm), or equivalent to diving to 100 m depth on Earth. 

I have no idea what the atmospheric conditions are there otherwise, for example is there too much wind turbulence for balloons to survive.

Even so I think it'd be very cool and even if the science had to be bent a bit I would like to have them in KSP2. 

Edited March 13, 2020 by Guest

[Bartybum]

Wow, now isn't that spicy. Cheers peeps

[Bartybum]

I probably should've asked about density rather than pressure.

[DStaal]

1 hour ago, Bartybum said:

I probably should've asked about density rather than pressure.

They're directly linked in this case anyway.  From that graph, it'll all be hydrogen down to well below where you want to be, so it's a simple ratio.

[Highrs]

I see people saying it wouldn't work... and I'm not sure why. As others pointed out, buoyancy is still a thing.

The idea is two-part - module and base. I'd love to see modules that let you float in the atmosphere (hot air balloons) but I also doubt any craft like that, especially a big one, would be a sable as a landing platform. The 'base' part would have to be some extension of the colony building system - more stable, larger, less parts. That's the one you could land on without summoning the Kraken.

Lifting off wouldn't be fun (or, alternatively, really freaking fun) but there are some really interesting possibilities with bases and modules like that. It's also a tech level that I imagine is lower than some of the engines they showed off.

Edited March 13, 2020 by Highrs

[mcwaffles2003]

12 hours ago, Brikoleur said:

Why not?

Making something orbit a gas giant while in its atmosphere isn't physically possible because of air resistance?

EDIT: Okay I see that OP is probably not talking about orbit but instead stationary, in atmosphere

Edited March 13, 2020 by mcwaffles2003

[Snark]

1 hour ago, Highrs said:

I see people saying it wouldn't work... and I'm not sure why. As others pointed out, buoyancy is still a thing.

If you want to float in a medium, you have to be lighter than that medium.  For example, if you want to float in air, you need to be lighter than air.  That's why helium balloons float on Earth.

If you want to float at a gas giant, then your balloon needs to be filled with stuff that's lighter than the atmospheric gas surrounding it.  In the case of gas giants, that stuff is often (for example, in Jupiter's case) hydrogen.  The problem is that nothing's lighter than hydrogen.  A helium balloon on Jupiter would sink.

Folks mention hot balloons because heating them up is one way to make that work-- e.g. a balloon full of hot hydrogen could float if surrounded by cold hydrogen.  But that then raises the problem of where you'll get an unending supply of heat from, that's light enough not to weigh down the balloon.  Thus the problem.

[Dirkidirk]

2 minutes ago, Snark said:

If you want to float in a medium, you have to be lighter than that medium.  For example, if you want to float in air, you need to be lighter than air.  That's why helium balloons float on Earth.

If you want to float at a gas giant, then your balloon needs to be filled with stuff that's lighter than the atmospheric gas surrounding it.  In the case of gas giants, that stuff is often (for example, in Jupiter's case) hydrogen.  The problem is that nothing's lighter than hydrogen.  A helium balloon on Jupiter would sink.

Folks mention hot balloons because heating them up is one way to make that work-- e.g. a balloon full of hot hydrogen could float if surrounded by cold hydrogen.  But that then raises the problem of where you'll get an unending supply of heat from, that's light enough not to weigh down the balloon.  Thus the problem.

How about a Vacuum?

[Star-Eagle]

There's a book called The clouds of Saturn which featured large floating cities. It's been a long time since I read it but I remember they were held aloft by massive balloons filled with hydrogen heated by nuclear reactors.

Could something like this work?

 

[DStaal]

2 hours ago, Highrs said:

I see people saying it wouldn't work... and I'm not sure why. As others pointed out, buoyancy is still a thing.

Some people who are saying it are probably thinking of the limitations of the KSP1 engine - in which case a ship out of focus is either landed, prelaunched, in orbit, or destroyed.  In either of the first cases it's stationary, in orbit it's calculated separately from the planet it's orbiting around.  This avoids having to deal with fuel, aerodynamics, ground collisions, etc. on unloaded vessels.

It's definitely possible that they could change this for KSP2 - but it's also quite possible that they don't.

[Guest]

39 minutes ago, Snark said:

But that then raises the problem of where you'll get an unending supply of heat from, that's light enough not to weigh down the balloon.  Thus the problem.

Fusion. Plenty of fuel floating around.

[Starman4308]

11 hours ago, Brikoleur said:

Pressure and temperature would not be a problem. You'd want to use a hot-air balloon because the atmosphere is 90% hydrogen. The volume, temperature, and mass determine the altitude at which it floats. You could easily make one that floats at 1 atm pressure, with whatever temperature is at that altitude. 

According to this graph (from Wikimedia), the temperature in Jupiter's atmosphere at 100 kPa (~1 atm) is about 180 K. That's on the chilly side, so if you prefer a more congenial 300 K, you'll have to go down where the pressure is about 1 MPa (10 atm), or equivalent to diving to 100 m depth on Earth. 

I have no idea what the atmospheric conditions are there otherwise, for example is there too much wind turbulence for balloons to survive.

Even so I think it'd be very cool and even if the science had to be bent a bit I would like to have them in KSP2. 

 

Really, I think the low temperature at the 1 bar mark is a plus.

You're going to need a hot-gas balloon anyways. With a low baseline temperature outside the balloon, you don't need the balloon to be as hot to get good buoyancy.

This also serves as a low temperature heatsink for fission reactors, or a nigh-endless source of hydrogen if you assume the presence of a fusion reactor. Solar panels aren't very effective out there, and wind turbines would require you to be attached to a solid surface; fusion/fission is the best idea I can conceive of anyways.

I could easily envision having a fission reactor at the bottom, cooled by hydrogen gas cycled through the balloon. Convection currents inside the balloon should really help.

And hey, there's one more advantage to balloons on gas giants vs. Earth/Kerbin: no pesky O2 to ignite after a lightning strike!

[Brynderion]

As others have stated, I imagine it depends on what atmospheric depth you plan on hanging around at. Hot air balloons come in all sizes and shapes, thus I imagine that a rather "flat" balloon would be necessary for a base you would want to easily escape from. Depending on the strength of the wind, you might even want to have a balloons that act as "wings" of a sort for any extra lift you can scrape from the environment.

If your power source is nuclear of either the fusion or fission variety (which I assume it is if you're brave enough to build a floating base on a gas giant in the first place...), you could most likely dump the waste heat of your reaction into the balloon to keep you afloat. As Snark has pointed out above — your reactor would need to be either very efficient or very small or, preferably, both. Again, this is something I assume you'd have the technology worked out for before starting such a project in the first place.

Now actually getting OFF the base is a different story altogether. If your deep enough down, anything with high enough quantity of both lift and thrust should be enough to get you up and out with relative ease. If fusion is your powerplant of choice, starting out relatively empty on propellant and filling up your tanks as you ascend would be way to go. It would probably be significantly easier to do on a hydrogen rich gas giant than with a more "mundane" combined-cycle air-breathing rocket on Earth or Kerbin (i.e. SABRE).

The immediate example that comes to my mind as a potential ascent vehicle is the SSTO-TAV37B "Valkyrie" from Avatar(2009). When the ISV Venture Star arrives at Alpha Centauri A, it uses fusion engines as its means to transfer into a lower Delta-V orbit around Pandora. After the two Valkyrie shuttles that are docked to it finish transferring personnel and payload to Pandora itself, they dip into the gas giant Polyphemus' atmosphere to scoop fuel to return to the ISV itself to make ready for the return voyage to Earth. The delta-wing shape of the vehicle should also be sufficient in making use of whatever lift there is to gain at a reasonable "fuel scooping" depth in a gas giant's atmosphere.

 

As for the idea itself...well, I don't think its completely necessary to the KSP2 experience, but it is something I would like to see in one form or another. If anything, I would imagine that the better physics for planets overall — rather than just a thin crust of textures wrapped around an empty void — would provide the tools for modders to be able to add it in time. If there are easy to handle tools that control the ability to build bases (and it isn't just permanently and obtusely tied to us being forced to build them a specific way on-world or off-world), then I imagine it would be doable.

In terms of what we already know — we do know that orbital shipyards, terrestrial body base-building, fusion engines, torch engines and specialized fuel synthesis (at least for Metallic Hydrogen) will all be in the game, and we already have mining and LF synthesis mechanics in the base game in the form of the mining excavators and the Covert-O-Tron. We can safely assume that there will be more fuel types than just LF and LMH — with Methane, pure H2, and H2/Ox engines being the most likely (and already present in popular, expansive mods like Near Future Propulsion/Cryo). Since intakes already scoop air in-game, I would imagine it wouldn't be so far of a stretch to have specialized intakes for scooping gaseous hydrogen (for fuel) or helium (for fusion) from atmospheres rich in those elements.

Finally with allll of that said, I see two ways it could possibly go down:

1) The more likely way is that you can build an orbital shipyard, attach wings, a reactor, intakes, and engines to it either while building it or through grabbing units (if you can't build however you want), then slowly lower it into the atmosphere of say, Jool. You scoop fuel for both the engines and reactor with the intakes, stay airborne with the massive lift provided by the wings and the thrust of the engines, generate power to stay on heading with the reactor, and basically set it and forget it until you need to launch something from it. If your reactor generates enough power, maybe propellers would be something worth using instead or as a fallback, depending on the density at your desired altitude.

2) Orbital shipyards and base building in general doesn't let you attach random parts to the base structure itself, even with workarounds like grabbing units. Your best bet in this case is to build a giant platform with a few miniature spaceplanes/rockets, habitats, and modules docked to it instead. A lot less interesting and you won't be able to build stuff at that particular "base", but still doable as long as you have the right parts for the job.

 

Anyway, those are just my 99 cents.

Edited March 14, 2020 by Brynderion
Spelling, etc.

[Starman4308]

I did a bit of research, and it'd be hard to pull off. The concept is more than a bit hampered by the general awfulness of trying to get buoyancy in a mostly-hydrogen atmosphere. I don't have the time to iterate over the entire parameter space, but I have a suspicion that you might want to go below the 1-bar level just so atmospheric density increases.

I assumed a 1000 ton reactor producing 100 MW of thermal energy, with the hot gas inside the balloon maintained at a nice cozy 298.15K (room temperature). I ballparked the Jupiter atmosphere as pure H2 at 200K/1 bar. To maintain 1000 tonnes of buoyancy, you'd need a spherical balloon 200m in radius. I then assumed as insulation it would have 2.5mm of fiberglass (which would itself mass ~2200 tons), and I got a heat loss of 893 MW, about 9x what is being produced. Submarine reactors with fiberglass insulation probably aren't the way to go.

Hyperion claims they can build a 15-20T reactor producing 70 MW of thermal energy, which is a roughly 35-45x improvement in power to mass. An array of these would get you past the break-even if the balloon itself can be made lighter. Advanced foam materials are better insulators than fiberglass, though structural integrity is also a concern.

Edited March 14, 2020 by Starman4308

[DStaal]

12 hours ago, Starman4308 said:

I did a bit of research, and it'd be hard to pull off. The concept is more than a bit hampered by the general awfulness of trying to get buoyancy in a mostly-hydrogen atmosphere. I don't have the time to iterate over the entire parameter space, but I have a suspicion that you might want to go below the 1-bar level just so atmospheric density increases.

I assumed a 1000 ton reactor producing 100 MW of thermal energy, with the hot gas inside the balloon maintained at a nice cozy 298.15K (room temperature). I ballparked the Jupiter atmosphere as pure H2 at 200K/1 bar. To maintain 1000 tonnes of buoyancy, you'd need a spherical balloon 200m in radius. I then assumed as insulation it would have 2.5mm of fiberglass (which would itself mass ~2200 tons), and I got a heat loss of 893 MW, about 9x what is being produced. Submarine reactors with fiberglass insulation probably aren't the way to go.

Hyperion claims they can build a 15-20T reactor producing 70 MW of thermal energy, which is a roughly 35-45x improvement in power to mass. An array of these would get you past the break-even if the balloon itself can be made lighter. Advanced foam materials are better insulators than fiberglass, though structural integrity is also a concern.

Sounds like something that scaling up - assuming you can handle the material strength issues - helps with.  Surface area per unit of volume would go down as the size of the bubble went up - put it in a dome over a 2km diameter mini-city, and and how much heat would you need?

[Incarnation of Chaos]

Is there any way to get lift in an atmosphere of mostly Hydrogen from airfoils? If so you might just be better off brute-forcing the issue by making a massive Fusion/Fission powered plane with Nuclear Thermal Jet Engines and flying around the planet on a regular pattern/schedule.

[Bartybum]

55 minutes ago, Incarnation of Chaos said:

Is there any way to get lift in an atmosphere of mostly Hydrogen from airfoils? If so you might just be better off brute-forcing the issue by making a massive Fusion/Fission powered plane with Nuclear Thermal Jet Engines and flying around the planet on a regular pattern/schedule.

As long as you have an atmosphere, you can have lift.

Assuming you have a flying fusion reactor that can scoop up the hydrogen and extract energy from it without violating energy conservation laws then it's totally possible.

In reality though, a permanent fusion aircraft would be neither possible nor responsible, because of material fatigue life and safety precautions (what if you experience a reactor shut down in flight? That's a likely goodbye sweet prince). Eventually you'd need to punch back into orbit, dock with a newer transport and then discard the old one. At that rate, it's likely more convenient just to have a dirigible.

To be honest, while they are cool as hell, I wouldn't really see any purpose in having dirigible installations/colonies versus orbital counterparts equipped with atmospheric skimmer aircraft to handle mining. Assuming compact fusion works, I feel like there's less material speculation with orbital installations anyway.