Best hydrogen source for Venus

[todofwar]

So let's say we decide to colonize Venus.* One of the major problems with long term civilization scale settlement is the lack of hydrogen, I did the math once and found you have enough water to fill a sphere roughly 12 miles across. Probably enough for a few million people, but you're going to start having more and more difficulty harnessing it from the air as time goes on. So, where is the best place to get some hydrogen? Earth? Intercept a comet and bring it to Venus? Europa? The rings of Saturn? One idea I had was to swing into Jupiter's upper atmosphere with a specialized nose that would collect hydrogen, either as a flyby or from orbit. I would say orbit is probably better, you can do a few passes until you fill up then boost your periapse to a more stable level.

*Note: This is not meant to be an argument over why we want to settle Venus. For that I direct you to:

Edit: Let's go ahead and put all feasible rocket tech on the table, this scenario is probably a couple hundred years in the future. If it doesn't defy the laws of physics, you can use it. 

Edited April 23, 2016 by todofwar

[jwenting]

Best thing to do with Venus is not colonise it, but leave it alone. Maybe send scoop ships to suck up the asmosphere if there's stuff there we need and can't get cheaper. Any human settlement'd better be in orbit, and orbit around earth or in the asteroids is probably a more advantageous location unless we decide we need Asimov style manned solar power plants closer to the sun in which case a station around Venus might serve as a staging area for maintenance and crew missions to those.

[kunok]

Well a starter should be the NVA (near venus asteroids), some of the NVA's should have some important resources of volatiles like water. We should start looking here https://en.wikipedia.org/wiki/List_of_Venus-crossing_minor_planets after all they are closest source of hydrogen.

And maybe there are undergrounds deposits. We should be able to make an unmanned miner robot with current technology, it won't be cheap at all, but I think is doable.

[todofwar]

5 minutes ago, kunok said:

Well a starter should be the NVA (near venus asteroids), some of the NVA's should have some important resources of volatiles like water. We should start looking here https://en.wikipedia.org/wiki/List_of_Venus-crossing_minor_planets after all they are closest source of hydrogen.

And maybe there are undergrounds deposits. We should be able to make an unmanned miner robot with current technology, it won't be cheap at all, but I think is doable.

I wonder if they will still have water that close to the sun though. 

[rodrigoelp]

@todofwar if you really are thinking on terraforming venus you will need to do something a tad more drastic... Quite possibly redirecting every NVO (near venus objects) and crash it into the planet. Venus should be able to take heavy blows given its incredibly dense atmosphere (heavy, but not destructive)...

Something similar to what happen here on Earth during the late heavy bombardment. That way you could hope to reignite venus core, recreating its magnetosphere (preventing the new hydrogen from escaping the planet) and giving it enough change to all of it to recombine with other elements such as oxygen and carbon to create water and organic compounds.

 

Sucking hydrogen from Jupiter is not possible with some kind of super long straw as the vacuum you need to create has to be greater than the gravitational pull from the planet... which is pretty strong... this is assuming of course that the straw can withstand the gigantic gravitational force differential between both ends without breaking up.

Ideally you would want something like Sedna or Makemake to leave its orbits and fall straight into Venus... the blow might get close enough to the core to make it liquid once more... although if it continues its slow spin the magnetic field will never be generated by the core convection currents.

[todofwar]

2 minutes ago, rodrigoelp said:

@todofwar if you really are thinking on terraforming venus you will need to do something a tad more drastic... Quite possibly redirecting every NVO (near venus objects) and crash it into the planet. Venus should be able to take heavy blows given its incredibly dense atmosphere (heavy, but not destructive)...

Something similar to what happen here on Earth during the late heavy bombardment. That way you could hope to reignite venus core, recreating its magnetosphere (preventing the new hydrogen from escaping the planet) and giving it enough change to all of it to recombine with other elements such as oxygen and carbon to create water and organic compounds.

 

Sucking hydrogen from Jupiter is not possible with some kind of super long straw as the vacuum you need to create has to be greater than the gravitational pull from the planet... which is pretty strong... this is assuming of course that the straw can withstand the gigantic gravitational force differential between both ends without breaking up.

There was this post I saw elsewhere on the internet talking about crashing comets into Venus to simultaneously strip away some atmo, give it more hydrogen, and speed up its rotation. Seemed plausible, but a bit drastic. I'm talking more city in the clouds type civilization. 

As for Jupiter, my thought was you get into orbit around Jupiter, then you drop your periapse just low enough such that you just barely enter the upper atmosphere and your speed compresses the hydrogen in front of you enough to start pumping it into storage tanks. Of course, this will also heat the hydrogen so you will need a way to deal with that, and the maneuver will lower your apoapse so you will be limited to a certain number of sweeps. Once your apoapse is starting to get a bit too low, or your tanks are full, you raise your periapse to circularize. No landing required.  

[kunok]

4 minutes ago, rodrigoelp said:

snip

I don't think he is talking about Venus terraforming, just to colonize the habitable part of the atmosphere. It's a lot easier.

12 minutes ago, todofwar said:

I wonder if they will still have water that close to the sun though. 

Yep probably are the biggest problem, but with the n-body gravity dance, some of them should be, I'm not talking about asteroids composed primarily of volatiles, but the ones that have a relevant portion of volatiles.

[AngelLestat]

The problem is not related to the amount of hydrogen that venus has vs the population needs, is more related to the cost of get it, I still think that collect sulphuric acid rain at 47km and then split the water from the sulphur would be way more cheap that get it from space, even taking into account future technology.
You can also collect pure water from 30km altitude using condensation, but no sure which would be more cost efficient..
There is a third option to get the water from ground aquifers as in earth. But we dont have data on how deep or the amount of water we can find, we just know that there is ground water due volcanic activity.

About asteroids, I would use them as fuel depot in orbit, so you don't need to rise the hydrogen and consume extra to leave venus low orbit.
Like this idea in TED talks, which seems better than my initial idea of painting the asteroid.

https://youtu.be/wLMHcUg36yc?t=3m39s

PD: Also dont think that the amount of water is fixed, first that sphere of water is more than enough to support our population and much more, people will also recycle water, and even if you can not recycle all (due different uses) it does not disappear, it stay in the planet. Venus is also always losing hydrogen due solar pressure, but it also receive hydrogen from volcanoes and hydrogen and matter that fall from space.

 

Edited April 23, 2016 by AngelLestat

[rodrigoelp]

18 minutes ago, todofwar said:

I wonder if they will still have water that close to the sun though

Messenger found ice on Mercury... distance to the sun does not indicate certain elements will be missing.

In the case of Venus the magnetic field is quite important to keep its elements from escaping the planet (unless of course you have those cloud cities completely sealed as the radiation and intensity of the sun will breakaway bonds between elements (the water will literally break apart and the oxygen will try to recombine with something with stronger bonds... like carbon).

9 minutes ago, todofwar said:

As for Jupiter, my thought was you get into orbit around Jupiter, then you drop your periapse just low enough such that you just barely enter the upper atmosphere and your speed compresses the hydrogen in front of you enough to start pumping it into storage tanks. Of course, this will also heat the hydrogen so you will need a way to deal with that, and the maneuver will lower your apoapse so you will be limited to a certain number of sweeps. Once your apoapse is starting to get a bit too low, or your tanks are full, you raise your periapse to circularize. No landing required.

Assuming we develop a robotic probe that is impervious to the massive radiation Jupiter generates, you could do something similar to what you suggest to collect it (also assuming you have an extremely elliptical orbit, because the hydrogen it tightly packed at 430km is around 0.4bars, at the surface of Mars, you would be exposed to 0.3bars) which means you would be exposed to a lot of heat just to maintain some kind of orbital velocity.

Any kind of population on Venus will have to recycle most if not all the water they have and protect it dearly... it may sound more beneficial then to build a space station around Venus with proper shielding from the sun to extract and establish a colony around it.

[Scotius]

If you have sufficient tech and available power to attempt the colonisation of Venus, you can also find a nice, big chunk of ice in Kuiper Belt and wrap it in reflective foil. Then strap couple of fusion engines and over the course of couple of years bring it to Venus orbit. Voila! You have enough volatiles to support your colony for decades. In case of increased demand or shortages rinse and repeat the process.

[todofwar]

1 hour ago, rodrigoelp said:

Assuming we develop a robotic probe that is impervious to the massive radiation Jupiter generates, you could do something similar to what you suggest to collect it (also assuming you have an extremely elliptical orbit, because the hydrogen it tightly packed at 430km is around 0.4bars, at the surface of Mars, you would be exposed to 0.3bars) which means you would be exposed to a lot of heat just to maintain some kind of orbital velocity.

Any kind of population on Venus will have to recycle most if not all the water they have and protect it dearly... it may sound more beneficial then to build a space station around Venus with proper shielding from the sun to extract and establish a colony around it.

Yes, it would be fairly elliptical. My thinking is you aim for a region where the pressure is extremely low, maybe 10^-3 bar or so, but you compress the air in front of your ship with some kind of funnel, such that the final pressure ends up being pretty high. The heated hydrogen could potentially serve as an energy source if you bring along some thermoelectrics, actually. 

The atmosphere of the planet does provide plenty of shielding, and the water that arrives won't be immediately dumped back into space of course. Still, if the population is to grow to the level of hundreds of millions of people, you're going to need to import more and more hydrogen. So even in the case of a perfectly closed loop, you will need exponentially more to handle the growth in population. 

[kunok]

@todofwar @rodrigoelp Why you would descend to Jupiter itself instead of harvesting from the ice of the outer moons? it takes a lot of less dv, why even go there when you can get for less dv in the belt? Or even the mars moons.

[todofwar]

1 hour ago, kunok said:

@todofwar @rodrigoelp Why you would descend to Jupiter itself instead of harvesting from the ice of the outer moons? it takes a lot of less dv, why even go there when you can get for less dv in the belt? Or even the mars moons.

You don't have to land with a Jupiter scoop maneuver, as I am now calling it. So you save some dv there. And I think of Jupiter as being an easier target to hit then the belt. 

[insert_name]

2 hours ago, todofwar said:

You don't have to land with a Jupiter scoop maneuver, as I am now calling it. So you save some dv there. And I think of Jupiter as being an easier target to hit then the belt. 

Easy to get there, not so easy to leave

[rodrigoelp]

10 hours ago, kunok said:

@todofwar @rodrigoelp Why you would descend to Jupiter itself instead of harvesting from the ice of the outer moons? it takes a lot of less dv, why even go there when you can get for less dv in the belt? Or even the mars moons.

That is my point exactly... Harvesting ice/minerals from asteroids around venus or bringing something from Ceres/Vespa would be a lot more feasible than having to get close to Jupiter... Plus some of its moons sit right in the Van Allen radiation belts which would be deadly for us.

12 hours ago, todofwar said:

Still, if the population is to grow to the level of hundreds of millions of people, you're going to need to import more and more hydrogen. So even in the case of a perfectly closed loop, you will need exponentially more to handle the growth in population.

Earth is an almost perfectly close loop, and we aren't running out of water even though the population has grown to be billions. The problem we are facing here at the moment is the massive wastage.

Again, harvesting near venus objects would be a more suitable idea.

Any colony on venus would have to be temporary anyway.

[Thomassino]

There is some hydrogen stored in sulphuric acid (H2SO4) molecules, also there is some water vapor, hydrogen chloride, hydrogen fluoride and other compounds, but all of these molecules aren't very abundant (we're talking in ppm territory). 

You could in theory built big processing plants with fans and produce some hydrogen, not much though. 

But if we are talking with 100+ years future tech, then transmutation is a possible solution too.

[kunok]

14 hours ago, todofwar said:

You don't have to land with a Jupiter scoop maneuver, as I am now calling it. So you save some dv there. And I think of Jupiter as being an easier target to hit then the belt. 

Is a lot cheaper in dv to get to the outer moons, and being so tiny the landing is very little. Or was you trying to aerocapture in Jupiter ? it would be easier to circularise with a gravity assist from one of the moons.

6 hours ago, rodrigoelp said:

Any colony on Venus would have to be temporary anyway.

Why?

1 minute ago, Thomassino said:

You could in theory built big processing plants with fans and produce some hydrogen, not much though. 

The extra energy of Venus would help a lot.

[todofwar]

@kunok actually, one could come in to Jupiter with an aero capture like maneuver but maintain escape velocity. So you never have to be trapped by Jupiter at all. Still, I'm starting to get convinced that any hydrogen you harness this way will get used up on the return voyage and your net gain will be low. 

@rodrigoelp I happen to be an optimist when it comes to space colonization, some day we'll have civilisations on every body in the system. 

So, what about a colony on Europa? They could send probes with hydrogen to Venus so you only need a one way trip. What's the dv situation like for a return from Europa vs getting all your hydrogen from Earth? 

[kunok]

3 minutes ago, todofwar said:

@kunok actually, one could come in to Jupiter with an aero capture like maneuver but maintain escape velocity. So you never have to be trapped by Jupiter at all. Still, I'm starting to get convinced that any hydrogen you harness this way will get used up on the return voyage and your net gain will be low. 

I don't see how an aerobrake maneuver for harvesting lots of mass, will keep the scape velocity at all, only if you have a very big initial velocity (not useful in a unmanned miner when you want the higher mass fraction posible) and some kind of heat shield.

 

Other thing I think... First I don't claim knowing really nothing about what I propose. There is a nuclear reaction than has hydrogen (or a proton) by product? I know that tritium can be done from lithium. After all hydrogen is only a proton and an electron.

Probably if there is one, manufacturing hydrogen would be a thing cheaper than harvesting in other bodies, Venus has a higher energy density than earth.

 

[rodrigoelp]

1 hour ago, kunok said:

Why?

Because building cities floating on the clouds of a planet that is literally an inferno, with corrosive rain and poisonous environment is mental, because in order to build said cities you need to bring almost every single building material from your home planet as you can not descent to pick up new materials. Any kind of presence would have to be for bridging purposes to a different celestial body.

[rodrigoelp]

20 minutes ago, kunok said:

I know that tritium can be done from lithium.

You would need to do fission (which splits the atoms). Lithium tends to be the byproduct of deuterium and tritium (the main product is helium). You could in theory in a stellarator (or tokamak reactor) absorb a neutron from deuterium plasma, the radical will create tritium by interaction with lithium, but you will need hydrogen to begin with to create this nuclear reaction.

[kunok]

17 minutes ago, rodrigoelp said:

Because building cities floating on the clouds of a planet that is literally an inferno, with corrosive rain and poisonous environment is mental, because in order to build said cities you need to bring almost every single building material from your home planet as you can not descent to pick up new materials. Any kind of presence would have to be for bridging purposes to a different celestial body.

There were addressed every one of this problems in the other threads. Resume: The corrosive rain at that hight is not that corrosive (good for the structures, bad for H harvesting), and we know how to deal with that, building materials will be carbon based so easily extracted from the atmosphere (the fact is a lot easier to extract materials from the atmosphere than to make a mining installation), it won't be that difficult to make a unmanned miner robot to the surface, and for recovering it it only needs a "blimp".

 

Ninjad

You would need to do fission (which splits the atoms). Lithium tends to be the byproduct of deuterium and tritium (the main product is helium). You could in theory in a stellarator (or tokamak reactor) absorb a neutron from deuterium plasma, the radical will create tritium by interaction with lithium, but you will need hydrogen to begin with to create this nuclear reaction.

Yeah. I know that, is not in theory is what they will do in the next version of the iter, https://www.iter.org/mach/tritiumbreeding , i was asking for other reactions.

Edited April 24, 2016 by kunok

[rodrigoelp]

@kunok You will still need a lot of hydrogen just to produce small quantities of tritium in a stellarator wendelstein 7-x.

I got lost: why were we talking about nuclear fusion? As a mechanism to produce hydrogen from on the atmospheric gases?

[kunok]

38 minutes ago, rodrigoelp said:

I got lost: why were we talking about nuclear fusion? As a mechanism to produce hydrogen from on the atmospheric gases?

I started as an example of a nuclear reaction that has an hydrogen isotope of product. I was asking if there are more that can be useful, instead of making interplanetary travel to harvest more. Not only because maybe is cheaper, also for resource independence.

[todofwar]

50 minutes ago, kunok said:

I started as an example of a nuclear reaction that has an hydrogen isotope of product. I was asking if there are more that can be useful, instead of making interplanetary travel to harvest more. Not only because maybe is cheaper, also for resource independence.

Not sure if you can split atoms down to protons. It may be possible, but the energy involved would be extreme. This could be feasible but I'm thinking the payoff would be small. If we have that kind of tech we probably can grab a large comet and start running a fusion drive to bring it to Venus.