A friend sent me this YouTube video earlier this morning:
While this video really covers a lot of the same ground as previous posts in my Venus ISRU series, it still got me thinking about where we stand as far as closing a plan for Venusian settlement.
As I see, it here are the big questions I’d still like to see more thought put into to help validate the feasibility of the concept of building settlements on Venus, in no particular order:
- Water and Sulfuric Acid are very low density in the Venusian atmosphere, but is it possible to extract water or sulfuric acid in useful quantities? I have some ideas, but not enough ChemE-fu to really analyze them.
- Are there materials you can make readily from Venusian atmospheric feedstocks that are resistant enough to Sulfuric Acid to serve as external layers for a settlement? I’ve done a little research on this, but have questions because I don’t know how to compare low-density Sulfuric Acid aerosols to the various SA concentrations in the chemical compatibility literature. For instance, since it’s very dilute, would HDPE or PEX work? Those are some of the easiest polymers to make off-world. This might require testing in a Venus cloud environment simulation chamber (we’d love to build one if people have money and are interested!). The reason this question is important is that if you can’t make the outer boundary layer from locally derived materials, that become a lot of mass you have to ship from earth–even if most of the elements can be procured locally.
- What construction materials can you realistically make locally? I’m digging into this one a bit, and it looks like I see pathways forward to simple plastics (PE/LLDPE/HDPE/UHMWPE/PEX, and PP), there may be pathways to more complex plastics that only rely on local materials, but I haven’t dug that far. I’ve also seen reasonable paths to carbon fiber (via PAN), and sulfurcrete, all assuming we can extract enough hydrogen from atmospheric water and/or sulfuric acid. But that still leaves a lot of questions unanswered. The more of the mass of your colony you can make locally, the less you have to ship in.
- How do you do the reentry, landing, and return to orbit transportation in a way that works safely and reliably, including aborts, rendezvous/landing with the platforms, etc. If you can’t get stuff safely and reliably down and back, Venus might end up more of a one-way trip than Mars, and it will be harder for it to participate commercially with the rest of humanity. Once again, I have some ideas, but actually fleshing out working transportation concepts is going to take a lot more work.
- What would a Venus cloud city really look like, if you look at the required gas envelope and structures made from realistically locally-derived materials? After factoring in all the required hardware to make a new unit cell, how much mass is left over for other things (like people, water, plants, etc). What does this mean for what a Venus city might look like?
- Once you know the end-state of a modular cloud city derived from local materials, how heavy is the ISRU hardware to start that process? What structural volume and air/water production rate could you sustain with an ISRU plant you can land in a single mission?
- What materials can you not derive locally from the atmosphere? How much of them do you need if you’re creative? Are any of them ones that could be harvested robotically form the surface? Do we have any good ideas for mining architectures to make that happen?
Anyhow, food for thought. If you’re interested in the idea of Venus cloud colonies, these are some of the questions I’d be focusing on.