Hot Air Ballons Outside Earth

If you're going nuclear you're better of ditching the balloon entirely in favor of powered flight. Nuclear Ramjet powered probes are probably the best option for in-atmosphere exploration of the gas giants.

www niac usra edu/files/library/meetings/annual/jun02/510Maise.pdf

But nuclear ramjet are much more complicated, not to mention not fully developed technology.

Hot air ballons are simple as fuck and reliable. Much better for an enviroment where there is no ground support.

Wont any electronic equipment fail after just weeks thanks to the radiation?

Probably. Radiation shielding would be too heavy and make the whole thing too expensive.

However, given that the longest we ever had a probe inside Jupiter while fully working was like 45 minutes I think 2 weeks would be a great improvement.

Nuclear powered balloons are a new technology, we've never built one. Deployment is a pretty big issue. Not to mention, the balloon would need to be HUGE.

The nuclear powered ramjet linked could do more, it could circumnavigate Jupiter

Nope. Jupiter's radiation belts are in space, not in the atmosphere.

But a ballon like that is still way simpler. It's pretty much a Nuclear reactor and a heating coil attached to it so It can heat up and fill the ballon.

See pic.

>Nuclear powered balloons are a new technology, we've never built one. Deployment is a pretty big issue. Not to mention, the balloon would need to be HUGE.
I also think it's worth pointing out that any nuclear balloon would likely end up using a design similar to the MITEE concept that the ramjet probe uses.

That said I don't think Balloon deployment is as big an issue as you think.The Soviet Vega program successfully demonstrated balloon deployment.

The main issues I see are getting the heat from the reactor to the air in the balloon and also possibly the wind. Oh and of course you have the major drawback that is a complete inability to choose where you go.

The vega balloons were pretty small

What's the point of probing Uranus, Jupiter, Saturn or Neptune?
I doubt we will learn anything new about them, we don't need probes to know their composition and it's obvious what's inside.

>Learning about the wheather from inside
>Testing the atmosphere to see if there are any undiscovered things there
>Taking awesome pictures
>Not being faggots that leave shit undiscovered

why not just make a nuclear powered propeller driven drone

>it's obvious what's inside
it's really not
The extent of our knowledge of jupiter's interior is "maybe lots of metallic hydrogen in there probably i unno how else would it be magnetic"

It's a good idea, but gravity is a bitch and it would need to be a very strong propeler with a very wide frame. The winds would probably tear it apart very fast and make it very hard to keep on air, not to mention the stress on the material to have a properler runing 24/7 could lead to the mechanical parts failing faster than we want.

just make a giant vacuum chamber

The Soviets actually already did it on Venus with the Vega probes. They were tiny and didn't last very long but they did work. They're not hot air balloons however.

There is a lot of interest in doing this on Titan, because of it's thick atmosphere and haze mapping the surface from orbit can only be done with radar (or badly in the infrared). With that same thick atmosphere a balloon can support a large payload.

Titan could use a Helium ballon which would be even easier and safer due to it's thick atmosphere.

It would be a sick way to explore. Have a probe that can just land, examine, and take off in a ballon to a different location.

How combustible is Jupiter?
Could I, in theory, set the whole thing alight?
What effect would this have on its moon and nearby planetary objects, as well as the solar system as a whole and overall?

To be fair,like any other atmosphere it gets more dense the deeper you go, with lighter elements/compounds tending to work their way up and heavier elements/compounds. An envelope filled with 100% helium ought to be buoyant at SOME level.

We've never built ANY sort of probe to float/fly around in the atmosphere, so all techniques are ruled out if that is the criterion.

Make the Atmosphere Great Again.

No oxygen. Not combustible at all.

And even if it was there is wheather there u silly willy. Lightining would have lit it up.

Ramjet is mechanically simpler. It's just pumping air instead of LH2 through modified nuclear thermal rocket's reactor. For a prop aircraft you'd need to create a small lightweight nuclear turbine. I'm hesitant to believe that you could make one that would match the mass of a ramjet. You could alternatively use an electric motor but that would be even more massive.

>What's the point of probing Uranus
oh I think you know ;^)

Correct me if I'm wrong but wouldn't using a hot air balloon on a gas giant be not much different than using one on earth? The atmosphere would just be less dense and therefore require a bit less heat (and subsequently energy) to take advantage of buoyancy?

You are wrong, we have successfull sent two balloons to Venus:
en.m.wikipedia.org/wiki/Vega_program
Pic related is one of the balloons.

Of course, the level at which this occurs might be well into jupiter's core. Helium is still denser than hydrogen even at pressures that make hydrogen metallic

Pure hydrogen, however, is lighter than the mixture of hydrogen and helium. So we can make hydrogen only balloons on jupiter, they just have to be quite large. However, it has been shown that a solar thermal hot air balloon could do this with less mass:

ae.utexas.edu/courses/ase261/balloon/PlanetaryMontgolfiere.pdf

The balloon ends up being quite large, about 50 meters in diameter. Overall mass ends up being around 112 kg to support a 10 kg payload.

This is less than the mass of the jupiter ramjet with 326 kg total mass. Although about 40 kg of that ends up being instruments and the ramjet concept is more fleshed out, so it's hard to compare apples to apples here

aw