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Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

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Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#41

Post by ck2 »

Cthulhu_ wrote: post #34
shagie wrote: post #8

Earlier quoted context omitted.

From the archives ... How much bigger could Earth be before rockets wouldn't work? https://space.stackexchange.com/q/14383 Feb 3, 2024 https://news.ycombinator.com/item?id=39243303 And related... https://worldbuilding.stackexchange.com/questions/178131/wha... https://physics.stackexchange.com/questions/117347/when-a-pl...

Man I love this. > Up above 10g, something really interesting happens that is kind of a theoretical limit. The mass of the rocket reaches a measurable fraction of the mass of the entire planet it's launching from.

one thing about physics, particularly astro-physics, is it's NEVER boring

been diving into PBS-Space-Time and DrBecky past few years as distraction from the endless nightmare of the world we are living in

this has been a great educational thread on HN too, I knew rockets would have to be bigger but didn't realize exponential and the 10g upper-limit

also puts the "Mars sample return" mission into perspective, very difficult

Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#42

Post by ck2 »

TheOtherHobbes wrote: post #33
inigyou wrote: post #7

Earlier quoted context omitted.

√(G × mass÷radius) [escape velocity] = v_e × ln(m_0 ÷ m_f) [Tsiolkovsky] Impossible to tell how much extra mass you need but it's exponential . Adding a unit of v_e [effective exhaust velocity] to escape velocity means you need 2.717 times as much fuel in an ideal rocket. Earth escape velocity is 11000m/s ignoring atmosphere (which is not ignorable). If the new planet is 6x mass and 2x radius then √3 times escape vel…

Perhaps that's why they're attempting to build a starship out of helium.

or it's all the "pollution" leaking from their fusion reactors ;-)

Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#43

Post by westurner »

pezezin wrote: post #30
idiotsecant wrote: post #17

Earlier quoted context omitted.

When you're done with it can I borrow your particle collider capable of mass synthesis of helium

The proper way to generate helium is to use a deuterium-tritium fusion reactor.

Given the neutron radiation from a fusion reactor, it's possible to synthesize Helium (He4) and more Tritium (T) and 3He using Lithium-6 with Boron-10 and Boron-11. An adjacent vertically-aligned (VA-CNT) battery would last for like 20 years and could power safety systems.

A Deuterated Vitrimer pipe with Li-6, B-10, and B-11 could be recycled to extract the T, 3He, and 4He.

Deuterated Vitrimers could also be disposed of in a waste burner.

Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#44

Post by westurner »

onion2k wrote: post #24
ColdStream wrote: post #16

Earlier quoted context omitted.

It is the four layers of resources, each one is smaller than the next. 1. What is the total theoretical resource? 2. How much of it do we actually now the location of 3. How much is technically recoverable? 4. And most importantly, how much is economically viable? The last one is really the crux of the problem nowadays, there is a lot of helium but most of it just isn't in a high enough quantity to make the investmen…

There will come a point when the price hits high enough to justify the cost but that also means higher costs to the end user. This makes me wonder if it'd be worthwhile starting a company to capture it now, and just stockpile it until it's rare enough to be able to use my stockpile to control the price. The DeBeers diamonds playbook applied to helium, or maybe the Peter Thiel build-a-monopoly-to-win approach.

A teal Hydrogen company that splits Methane (CH4) into Hydrogen (H) and Oxidized Carbon Nanotubes (O-CNT) would be significantly more profitable than one that splits into Hydrogen and Carbon Black. (Because after production costs, O-CNT have a significantly higher market price than carbon black.)

But do our communities want fracking wastewater in our aquifer groundwater or on our farm fields?

When is the break-even point for cracking Helium from natural gas at current and predicted Helium market prices?

Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#45

Post by TxFkdZ »

trhway wrote: post #29
deepsun wrote: post #25

Earlier quoted context omitted.

The problem is radiation. Empty space is not really empty, there are stray atoms floating around. Very scattered, but at a high impact momentum penetrate the ship ionizing anything in their way, and making the ship itself radioactive. Not even talking about stray high-energy particles from distant supernovas and magnetars -- those irradiate ship regardless of its speed.

anything going out there for those long journeys would/should be big, so there would be enough walls, storage of supplies, reaction mass tanks, etc. to provide significant protection.

Not really. Galaxy is 100k ly across, you can make the journey end to end in 1mil years at 10% light speed. Obviously talking about probes/tech, not "biologicals".

1mil years is really short in the grand scheme of things.

Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#46

Post by shagie »

ck2 wrote: post #41
Cthulhu_ wrote: post #34

Earlier quoted context omitted.

Man I love this. > Up above 10g, something really interesting happens that is kind of a theoretical limit. The mass of the rocket reaches a measurable fraction of the mass of the entire planet it's launching from.

one thing about physics, particularly astro-physics, is it's NEVER boring been diving into PBS-Space-Time and DrBecky past few years as distraction from the endless nightmare of the world we are living in this has been a great educational thread on HN too, I knew rockets would have to be bigger but didn't realize exponential and the 10g upper-limit also puts the "Mars sample return" mission into perspective, very dif…

Playing with the trajectory browser at NASA is kind of neat.

https://trajbrowser.arc.nasa.gov/traj_browser.php?NEAs=on&NE...

The "view" at the bottom has an animation of the various routes. They're all EM-ME though...

If you pick some other interesting targets you can get EVJS or something like that (launch from Earth, Gravity assist at Venus, Gravity assist at Jupiter, rendezvous with Saturn)... and then the trajectory animations are much more interesting.

Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#47

Post by dreamcompiler »

onion2k wrote: post #24
ColdStream wrote: post #16

Earlier quoted context omitted.

It is the four layers of resources, each one is smaller than the next. 1. What is the total theoretical resource? 2. How much of it do we actually now the location of 3. How much is technically recoverable? 4. And most importantly, how much is economically viable? The last one is really the crux of the problem nowadays, there is a lot of helium but most of it just isn't in a high enough quantity to make the investmen…

There will come a point when the price hits high enough to justify the cost but that also means higher costs to the end user. This makes me wonder if it'd be worthwhile starting a company to capture it now, and just stockpile it until it's rare enough to be able to use my stockpile to control the price. The DeBeers diamonds playbook applied to helium, or maybe the Peter Thiel build-a-monopoly-to-win approach.

This is both a bad and a good idea.

First the bad: Helium is very expensive to extract and store. You'd need a lot of venture capital. And you'd have a tough time competing with Qatar which produces between 1/4 and 1/3 of the world's supply. Qatar already is the DeBeers of helium.

The good: When the US/Iran war started helium prices shot up, so there might be an opportunity for a helium supplier not dependent on the Strait of Hormuz.

https://www.reuters.com/business/energy/helium-prices-soar-q...

Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#48

Post by Tagbert »

pixl97 wrote: post #4
ck2 wrote: post #3

wow 50 light years is indeed "nearby" in relative terms nearly 6x the size of earth though, good luck trying to launch a probe off that surface NASA has a neat "exoplanet catalog" which is about to leap in size next few years with new telescopes and techniques * https://science.nasa.gov/exoplanet-catalog/lhs-1140-b/

6x time size (diameter?) or 6 times the mass. Evidently the Earth used to be much larger in size but not mass because of large amounts of trapped hydrogen/helium. It's since leaked from the crust and been blown off into space.

Do you have any reference for that? I have a hard time seeing how that would be true once the components were coalesced but maybe before that.

Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#49

Post by westurner »

fragmede wrote: post #28
onion2k wrote: post #24

Earlier quoted context omitted.

There will come a point when the price hits high enough to justify the cost but that also means higher costs to the end user. This makes me wonder if it'd be worthwhile starting a company to capture it now, and just stockpile it until it's rare enough to be able to use my stockpile to control the price. The DeBeers diamonds playbook applied to helium, or maybe the Peter Thiel build-a-monopoly-to-win approach.

That's where the government reguli could step in. It wasn't economically viable to capture natural gas so it's just flared off, but if the government fines oil companies for flaring off the natural gas, suddenly it's economically viable to capture it instead of wasting it.

It's economical to capture and sell the Helium out of natural gas even without a flaring penalty to encourage to be efficient with heat and material outputs.

It's also already economical to make Hydrogen and Carbon-based products like Graphene and spec Oxidized Carbon Nanotubes from natural gas.

https://news.ycombinator.com/item?id=48946629

And, it's surely also profitable to make more He3, He4, and T with a fusion reactor: https://news.ycombinator.com/item?id=48946533

Re: Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone

#50

Post by westurner »

actionfromafar wrote: post #39
automatic6131 wrote: post #35

Earlier quoted context omitted.

Doing economically inviable things is waste. It's pumping resources into something worth less than the sum of its inputs. Apropos of nothing, see one trillion dollars into datacenters.

That is exactly it - how do we define economically inviable? There are many answers, very different.

Total cost estimates should included unassessed environmental hazard, carbon, energy mix
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