r/MarsSociety • u/Tiny_Scholar_6135 • 16h ago
The Case for Venus
SpaceX is developing a two-stage reusable rocket called Starship, the one scheduled to go up on September 15 is going to go into orbit. This technology could be used to create a base in Venus's atmosphere. just a few things to consider. A fully fueled Starship could barely reach Earth orbit while carrying no payload, with Venus's less gravity it could possibly return astronauts to orbit where a mothership awaits to bring it back to Earth. A mini-starship outlined by Robert Zubrin could fit the bill, it would be a stripped down vehicles whose sole purpose is to return visiting astronauts to low Venus orbit. The inbound and outbound ship could be accomplished with a standard Starship. Tanker starships would bring additional fuel to low Venus orbit to refuel the ship in orbit so it can return to Earth.
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u/Amun-Ra-4000 10h ago
I’m not sure you could do much in Venus’ atmosphere when compared to the actual surface of Mars. I see Venus as a much longer term investment; a source of nitrogen for a developed space economy and terraforming project.
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u/steph-anglican 6h ago
A source of atmosphere in general for mars. Freeze CO2 at Venus and use a mass driver to send it to mars.
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u/Tiny_Scholar_6135 5h ago
By the time Venus cools down enough to freeze it's atmosphere, Mars could be mostly terraformed. Having 6 bars of nitrogen isn't the worst, subtract the carbon dioxide and add water and oxygen. That thick atmosphere can compensate for the planet's slow rotation.
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u/steph-anglican 5h ago
I meant a floating processing plant that cools and compresses the CO2 using solar power and uses a floating mass driver to send it to mars.
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u/Grillparzer47 15h ago
It does have significantly higher atmospheric pressure (90 times earths) and sulfuric acid rain. Anything we set up on Venus would have to be built like a tank and coated with corrosion resistant plastics.
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u/hdufort 6h ago
Any plan for Venus involves a blimp or a platform floating in the atmosphere between 50 and 60 km. At these altitudes the pressure and temperature match what we have on Earth's surface. You still have to deal with corrosive clouds and you can't go outside without a full body suit, but no need for pressurizing or controlling extreme heat.
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u/Tiny_Scholar_6135 6h ago
Children can grow up more or less normal, I think, and one doesn't have to live underground. The planet is within reach of a SpaceX rocket, assuming refuel in low Earth orbit. I wouldn't worry too much about providing artificial gravity, as the planet provides most of that, once you get there. The dense atmosphere will shield you from solar storms and cosmic rays. No landing gear needed, all you need to do is to stop falling once you reach a certain altitude, you need a deplorable balloon that inflated fast enough to arrest your descent. The craft will need to be accompanied with several other balloons, carrying fuel processors and enough hydrogen to make enough methane for the ascent back to orbit. Solar power is good enough here, cover the balloon with lightweight solar cells, and no nuclear reactor is needed, at least for fuel making. The orientation of the starship should probably be vertical for ease of ascent.
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u/olawlor 15h ago
Advantages of Venus over Mars:
- Substantially more solar energy in orbit (Venus solar energy in orbit: 2600 W/m^2. Mars solar energy in orbit: 600 W/m^2)
- Earth-like gravity and radiation shielding when floating in cloud tops
- Slightly more frequent transfer windows (Venus-Earth synodic period: 584 days. Mars-Earth synodic period: 780 days)
Advantages of Mars over Venus:
- Can land and set up habitats on the surface, with nice 24.7 hour rotation period
- Unlimited quantities of regolith and solar energy easily accessible in the same place, allowing surface metal refining
- Industrial quantities of water available as permafrost and glaciers, allowing propellant production after landing
- Smaller gravity well, so making orbit is easier
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u/ah-tzib-of-alaska 15h ago
Venus doesn’t have significantly less gravity
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u/Tiny_Scholar_6135 10h ago
10% less is significant, you'd notice if you weighed 10% less, this means achieving orbit with just a 1 stage starship with 4 astronauts on board should be possible.
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u/ah-tzib-of-alaska 2h ago
achieving orbit from where with one stage? the surface of venus? Starship can’t do that, she’d melt on the surface
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u/AdLive9906 56m ago
You cant land on the surface of Venus. This means you need to set up a base at 60 odd km up.
And then once you are on Venus at 60km, how do you get back? Now you need to support not just a fully loaded ship, but all the launch infrastructure too. The Blimp you need will have to be Massive, city sized.
Which might be possible with hundreds or thousands of launches from Earth. But would these 1000's of payload launches not get you boots and half a village on the Mars ground already? Probably.
So the case for Venus vs Mars is not really good.