NASA, SpaceX, CNSA... all organizations in space right now seem to have their eyes on the Red Planet. But what if that were to change, and the main goal of manned spaceflight redirected towards Venus?

Suppose that a "MacGuffinite" sufficiently motivating to land humans on Venus is found in the near future. What form would this motivation take?

The MacGuffinite must be:

  1. Politically and economically stimulating - human spaceflight advocates have spent decades, especially in the United States, campaigning for both politicians and scientists to send a manned expedition to Mars; any stimulus to change that impulse should probably be very far-reaching.
  2. Something requiring a task that only humans can execute. No robot sample return allowed. "Science fiction fans relate more to human beings than to silicon chips." - (Burnside's Zeroth Law).

Note: as the quote above indicates, the question is more tailored towards answers that would work well in a (probably near-future) science fiction story than necessarily hard-science studies.

I would appreciate any and all answers. Thank you!

  • $\begingroup$ What form would the macguffin take or the probe? Some ambiguity here. $\endgroup$
    – Trioxidane
    Aug 22 '21 at 13:26
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    $\begingroup$ There isn't a particular reason to go to Mars; what there is, is a plausible method to do so. Venus is massively more inhospitable, to the extent that it's not clear what a manned mission could even look like (high altitude balloons of some sort are the best suggestion I've seen). So your McGuffin had better be good - but then, plenty of stories have handwaved "the thing that's going to save humanity" or just "astonishing riches". $\endgroup$
    – IMSoP
    Aug 22 '21 at 14:26
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    $\begingroup$ I think the problem is that humans landing on Venus would either be committing suicide by doing so, or would have to be genetically engineered virtually beyond recognition as human, or would have to be hidden behind so many layers of protection that they might as well remain in orbit around Venus (or at least high in the Venusian atmosphere) and tele-operate the landing machinery from there, since it would be the same experience for them either way. Given all that, it's hard to think of a justification for landing them. $\endgroup$ Aug 23 '21 at 1:29
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    $\begingroup$ @Lelu NERVA is going to suffer the same problem all rockets will on Venus--the tremendous pressure will seriously degrade the performance of the rocket. NERVA Vacuum ISP: 841. Sea level ISP: 710. What is it going to do at 92 atmospheres? You're going to be going slow in that thick atmosphere, you're going to take a lot more gravity loss also. Nobody's built an airplane or balloon remotely big enough to get an orbital-class rocket high in the atmosphere. $\endgroup$ Aug 26 '21 at 4:13
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    $\begingroup$ @MolbOrg Square-Cube law. The bigger it gets the more mass must be used for internal structure. $\endgroup$ Aug 26 '21 at 14:09

Alien artifact.



Maybe a satellite probe around Venus picks up an ancient automated distress call. Or better - watchers around the world saw this thing careen into our system and crash into Venus.

It is down there. Whoever arrives first gets it.

MacGuffin within a MacGuffin - send threatening rivals offworld. there are powers on earth eager to send certain persons or groups to a place they are unlikely to cause trouble and unlikely to return home from. Maybe these are superhumans? Maybe these are groups like the US Air Force in the show Stargate - an entity which through alien tech acquisitions has jumped far ahead of its counterparts at home and abroad.

Powerful groups would be a sensible choice for a mission like this. People at home might hope that the various deployed groups fight each other to their deaths on a faraway world.

I am picturing the scene where the UN mission arrives only to find the landing craft of the Australian billionaire is already there. Then there is a knock on the door and two very haggard North Korean metahumans ask to please be let inside.

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    $\begingroup$ +1, this is a scenario that can provide sufficient urgency to send a manned mission. In most other cases, we may be content to send robotic landers and wait for years for them to get the results. $\endgroup$
    – Alexander
    Aug 23 '21 at 4:18
  • $\begingroup$ @Alexander adding the need to support human life on the surface of Venus to your mission requirements is not going to accelerate things. We were able to build probes capable of limited-duration operation in that environment half a century ago. In another half-century, we might be able to land humans. $\endgroup$ Aug 26 '21 at 12:59
  • $\begingroup$ @Christopher James Huff this depends on what we are calling "things" If landing a robotic probe on Venus is the "thing", then of course not. I am trying to assess a scenario when landing humans is requirement. $\endgroup$
    – Alexander
    Aug 26 '21 at 16:45
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    $\begingroup$ "Whoever arrives first gets it.": the problem is to "get it". That is the "thing" you need to do. If you insist on bringing humans into a 737 K 93 bar environment at the bottom of a 10.36 km/s gravity well, someone who's fine with a robot will beat you there by decades. This isn't like Mars or the moon, keeping a human alive down there will take a massive vehicle constantly expending enormous amounts of power to keep its occupant from being cooked. $\endgroup$ Aug 26 '21 at 20:07
  • $\begingroup$ @ChristopherJamesHuff - and therein lies the story! $\endgroup$
    – Willk
    Aug 26 '21 at 23:33

Fossils as MacGuffins

I'd like to propose that the motivation doesn't necessarily need to be something objectively valuable (like a MacGuffinite mineral). It could be something with a high subjective value. For example: if a robotic lander discovered unambiguous evidence of extraterrestrial fossils on Venus's surface, I can imagine there being a race to collect and preserve them before they're degraded any further by the harsh environment.

This by itself might not be motivation enough to send humans to the surface rather than simply building better robotic landers. But suppose the robotic landers also discover unambiguous evidence that the Venusians went extinct at the same time as a mass extinction on Earth, or that they went extinct at a time that corresponds to some previously-undiscovered solar-system-level catastrophe. If there was any hint that a similar catastrophe might be in the near future, there'd be a massive incentive to study the fossils as thoroughly and quickly as possible, which might leave humans no other choice than to go down to the surface themselves.

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    $\begingroup$ Remote controlled excavation robots. It is much easier (but still horrifyingly difficult!!) to make a mechanical mechanism that can function on Venus surface, compared to a Human-habitable vehicle or dwelling. Venus' surface is less friendly than the inside of a lava crater in a volcano. $\endgroup$
    – PcMan
    Aug 26 '21 at 10:13
  • $\begingroup$ @PcMan That is a fair point. My engineering knowledge is pretty limited, but here's how I see it. The high pressure and the acid in the atmosphere could theoretically be worked around in a human-carrying vehicle. I think the high temperature would be the hardest issue to work around. How do you cool anything when everything around you is 430C and above? The best solution I could come up with was dropping, say, insulated tanks of cryogenic nitrogen or helium from orbit, to be used like consumable fuel tanks. But I'm not that confident in that solution. $\endgroup$ Aug 26 '21 at 13:57
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    $\begingroup$ I think you could build a nuclear-powered rover (with or without human habitation inside), that uses literally red-hot molten sodium coolant loops to the outside, and a nested cooler for the interior.It would be horridly inefficient, as the temperature difference between your nuclear core and the cooling side would be only 300K or so at most, and the temperature difference between your coolant and ambient air will be even much less. However the high air density will make convective cooling very effective, as long as you are willing to live with 430C as your "low" temp for the outside coolers. $\endgroup$
    – PcMan
    Aug 26 '21 at 14:48
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    $\begingroup$ But it will be large, massive, and it will be very very expensive, both to build and transport to Venus. The MacGuffin had better be something of ludicrous value, mere pre-smelted blocks of pure gold and platinum are not even worth mentioning, it would have to be something a magnitude (or 2 or 3) more expensive and valuable than that. $\endgroup$
    – PcMan
    Aug 26 '21 at 14:50

James Cameron's Unobtanium

Venus is a hellish place and I wouldn't be surprised if we can't land humans safely there this century. It's 90 atm of highly corrosive atmosphere at its mean altitude.

So the only way this could be worth it is if there is something there that helps us do something grandiose such as becoming an interstellar species.

For those who have not watched James Cameron's Avatar, the Macguffinite in the movie is an ore with negative mass. In real life such a thing could violate the second law of themodynamics due to a theoretical property of mass called "runaway motion". In an ideal scenario, if you tether two bodies of the same mass value but different mass charges in space, they will quickly accelerate to near light speed in the direction of the positive mass body without spending any energy.

That would be more valuable than anything else we can ever dream of.

  • $\begingroup$ The Unobtanium in Cameron's Avatar is not of negative mass, but a room temperature superconductor. The floating mountains are also explained with that. That's why it's so sought after: it solves a lot of problems with energy distribution (and probably a lot other problems) back here on Earth. $\endgroup$
    – D. Kovács
    Aug 23 '21 at 8:46
  • $\begingroup$ But you can mine exotic ores with robots. And realistically, if you put a human on the surface they'd have to interact with the outside world through robotics. $\endgroup$ Aug 26 '21 at 13:09
  • $\begingroup$ @ChristopherJamesHuff there was a lander sent to Mars to dig soil. As a lander, not a rover, it can't move. It landed on a rock and was unable to dig because of that. A human with a portable drill wouldn't have the limitations of a robot. $\endgroup$ Aug 26 '21 at 14:11
  • $\begingroup$ @TheSquare-CubeLaw a Venus mining robot is not going to be a fixed lander with 50 kg of instruments, it's not going to dig ores with a <1 kg self-digging subsurface thermal probe with a 2W power budget, and a human with a portable drill wouldn't be able to do anything. You're not going for a walk in a spacesuit on the surface of Venus. Just engineering a drill to operate in that environment will be non-trivial, and making it portable does not make the problem easier. $\endgroup$ Aug 26 '21 at 14:50


Fun fact: Venus is actually the better choice! Venus has earthlike gravity, a working magnetic field, a thick, protective atmosphere to go with it, a lot more available solar energy - what with being closer to the sun - and more frequent launch windows coupled with closer closest approaches.

Okay, yeah, actually making landfall is a terrible idea, but we don't need to! The atmosphere is so thick and dense, breathable air at atmospheric pressure is a lifting gas. Space zeppelins, anyone?

This idea is so tenable, NASA has actually published a study detailing how it would work, the High Altitude Venus Operational Concept (someone had fun with that acronym, I'm sure).

  • $\begingroup$ For unusual definitions of "better". Venus has no intrinsic magnetic field, the induced field it has is very weak and provides little protection, and the portion of the atmosphere at ~50 km altitude with Earthlike temperatures and pressures is also the portion with the densest clouds, so there may not actually be much solar energy available. The effective solar day is also ~72 hours long...this is better than the moon (and much better than the solar day of the planet below), but means you have to run off batteries for 2 (Earth) days and tolerate ~1 day with the sun close to the horizon. $\endgroup$ Aug 26 '21 at 16:13
  • $\begingroup$ It also doesn't matter how close the closest approach is, actual transfer trajectories will have spacecraft near the opposite side of the sun from where they started when they reach their destination. And if you aren't going to the surface, your available local resources are just CO2, N2, and some sulfuric acid. A Venus atmospheric colony would have to import almost everything, with nothing to trade that can't be gotten easily elsewhere. $\endgroup$ Aug 26 '21 at 16:23

With certain technologies, Venus can be quite an attractive place, because of 3 or 4 factors.

  • it probably(/may) does not fit what you envision or some of your requirements, those are just a few, I would call legit reasons/factors, if not then handwavium is always available.


Atmosphere of Venus is 96.5% Carbon dioxide and a mass of 4.8 × 10^20 kg, it about 0.7% of the mass of Luna, and about 20% of the total mass of the asteroid belt.

Attractiveness lays in that it can be extracted without landing on Venus with means of orbital scooping, similarly to this one http://toughsf.blogspot.com/2017/09/low-earth-orbit-atmospheric-scoops.html (u like big pages, eh, so here you can enjoy it as well)

Oxygen is more or less useless, but if there is the transport of hydrogen it can be used to make water as well, at least it can be more convenient to store the stuff, for future uses.

3.5% of Nitrogen also is an interesting component. It looks like a negligible number, but considering that Venus's atmosphere is about 90 times more massive than earth's one, this number represents more than 3x the content of Nitrogen in the earth's atmosphere.

It can be useful for creating a breathable atmosphere in space habitats as an example. As basically there are just 2 easy sources of Nitrogen for early space stages - is the earth itself and Venus.

  • At the moment, we are not at the early space stage, if someone is curious, ehh how to say that, mm, we entertain us with the idea of space, and are at an orbital stage, early or middle of it. Moon could be advanced orbital stage.

Carbon can be used for carbon-based nanotech, but without that, it has some uses.


It is less a thing on its own, but there is an interesting aspect of Venus - in some sense, it is a big battery of heat energy.

So that surface temperature of 740 K (467 °C, 872 °F), it actually energy stored in heat form. Mars has great research value but poor space colony value, and that poor score for space colony place is exactly because of poor sources of energy on mars.

The difference in that energy aspect can be negligible if fusion reactors, compact and sufficiently powerful are available, and fuel is available and all that, so this advantage is temporarily, but still energy stored in form of heat on Venus is quite a respectable number about 2 × 10^26 J, one can be tired counting it in oil barrels.

The attractiveness of that is in our abilities to extract that energy with simple means, being on Venus, in upper parts of the atmosphere, floating at around 50km altitude. And from that perspective, Venus looks like a big oil field.

This energy extraction can be part of a process of cooling down installations on the surface of Venus. This not only extracts energy for the upper part but also provides liquid CO2 for the ground part which is used to keep the temperature and provide energy.

  • It does not solve the high-pressure problem, if you envision humans on the surface, then it is an additional challenge, but make one challenge less that is relatively simple. And that challenge is only relevant to human presence on the surface, which can be quite pointless with teleoperating from orbit.

The fundamentally important part here is that expansion, of whatever one is interested to do on Venus, can be really fast, because more or bigger the system is, faster more energy it can extract this way, and more of your goal on the surface it can do. 24.7.365

  • sure it is true for any other energy extraction process, but the density of energy and corresponding EROEI can be higher than on mars, where without fusion there is not that much energy, and its density is not that great.


It can be that crust of Venus is 10 to 20 km thick, which means we probably can get to magma layers to extract those. The situation is much better than on continental areas on earth, but not necessarily as good as ocean bedrocks.

And that again means access to energy for whatever activity, so as materials - basically a rock well - drill it once and then just sit on one place and get materials for "infinity".

  • and if we screw up in the process, no one really cares. it can be a testing site for similar technologies on earth for all those gree guys. Green guys invest in Venus, save the earth.

proximity to the sun

Considering the big pile of resources which Venus is, its next competitor Mercury is not necessarily a winner. It may or may not be an interesting factor.

Mcg .. Macguff... ..tinite ... What What?!?!

The problem with explanations that rely on some single reason for explaining why things do happen sure may make it easier for a writer, but it never happens, and honestly never believable or interesting. Oil on earth without all the technological achievements we have is useless and not worth the effort.

So things, events depend on the context in which they happen. What is there for them to happen? It gives a possibility for some things to happen, like a sufficient level of technologies, to the reason for them to happen.

Atm Venus and Mars are equally useless. For regular folks, like senators who sign NASA bills, so as taxpayers which pay them - it appears like a significantly bigger challenge than Mars. And with continuous successful mars programs, it seems like an irrefutable fact. And it looks like there is no justifiable cause, nothing can explain it in any other way than money drain, especially when one is fixed on reaching the surface, bathe himself in the dust of a celestial body, do ... hm idk unspeakable things with it, eh(?)

That low orbit air scooping isn't such fantastic technology, at least it does not look like for some people in that camp, even if for those who are not in it, even if they are smart otherwise there is no way to break their defense.

  • proofs may be a bit on the conspiracy side, but there are(?) LEO military satellites which do change orbits and they may use similar technologies, as engines suitable for that are announced by ESA a few years back, so components are there, and they aren't that much different from what's already in use.

So even with today's technologies, we could start to tap resources from the planet, Venus. Which could have a chain of events allowing us to occupy orbit, upper atmosphere (that 1 bar line) and gradually get to the surface, and start to get resources from it.

Producing regular carbon fiber from CO2 is not impossible, and it can be a base product for making descending modules that do not land but float, and from there continue to the surface and create that energy extraction cycle.

It is possible to say that Venus is more difficult, but at the same time that scoop probe, how is it more difficult than the current mars rovers. Reaching Venus's surface can look more difficult, but how is it more difficult than establishing a Mars colony, a colony won't grow on its own, apparently.

Both cases require exporting our technologies in space, be able to use our accumulated knowledge to make things in space, create material tools there from materials available.

In that sense, Venus has what it takes to make use of it, so as Mars, so as Moon.

It can provide what the other 2 bodies have a hard time providing, it has certain advantages and opportunities.

Early air scooping on Venus, can be a decent match with Moon activity, and in that aspect, both locations Mars and Venus have advantages and disadvantages, advantage of Venus is launch windows are more often so one can get more in the same period of time(19 vs 26 months), delta-v is a bit bigger but not by much and considering oxygen is not needed on both ends, plasma drives will have plenty of reactive mass to use.

Scientific value - all places are interesting. Someone posted about life as potential reasons to jump the train and here I stumbled on the article https://www.technologyreview.com/2020/09/16/1008478/venus-soon-as-possible-phosphine-clouds-astrobiology-life-veritas-davinci/ some suspicious phosphine clouds were spotted.

So if you compare Mars and Venus (hey, where is the moon) both places have scientific reasons, it just matter of - do you have what it takes to go there, I mean money(?), rockets, whatever.

You do not have to have that McWhatWhat to go, in essence, we still know not enough, for to not to say too little, that we have no reasons not to go to all places we can go to in the solar system. The exception is probably the sun, I mean it is hot.

Do you understand what it takes to investigate/research a planet - I mean you can justify the presence of millions of people busy doing that, in situ or teleoperating equipment from orbit and do initial data processing, managing the whole process. Ping from the planet to those planets won't go anywhere in near future ever.

And a planet is not a backyard, or a country, or earth which we have access to and we still prospecting for which materials are where.

So honestly, no one needs an McWW to go there, there are regular reasons, so as future benefits to go there.

Delivery of resources to space, as a note

Venus has some problems with that, I can recognize it, Mars has a similar problem, but yes we can say it looks like Venus has a bigger one, gravity alone is enough to see that.

But again it depends on the user goals, for carbon scoop extraction, the amount of resources required isn't big, and for the similar capacities we have today on earth, in terms of resource delivery to orbit, floating platforms can be enough, rockets do not have to be big, similar to sea launch approaches. If it can deliver its hull to orbit then great - exactly what we needed. 100kg payload class of rockets. It just needs a conveyer of those, and making one having certain setups on Venus is an achievable feat.

  • with carbon as staple construction material(in orbit, ground a different story), the rest of the materials required are limited. Even if we do not plan to make chips out of carbon, it may be possible but we do not have technologies for that, percentage of those materials metals, and others are not high, 1 to 2 order of magnitude less than the main construction material. The reason is that in microgravity any solid material can be structural material, and carbon with its allotropes is quite a good one. And considering water will be available for the scoop, in ppm concentrations but still, so as N, S it can be used for plenty of different stuff easing restrictions of the bill of materials in a significant way.

So as there are non-rocket and rocket/orbit assist approaches (for a second one, I know only one interesting idea, and coined the "term" for it) so it is feasible with current technologies, and meaning in foreseeable future. Having nerva would be not necessarily an improvement and it would be rather unnecessarily overcomplicating things, and definitely not Orion - less vodka makes life better, sometimes, lol.

  • launch loop is quite a promising approach, its main problem is that if it fails, and with our technologies it not 'if' but 'when', it can deliver quite a damage. On Venus if it delivered something to orbit and then broke it still a win, next one please. And considering all the energy available and that there is nobody there, we can break 10's of those or a hundred and it makes no difference. Even if it does not deliver anything, we can test and perfect it until it does, no oil barrel harmed in this testing, no nuclear fuel rod is wasted and as for the materials - dust to dust.

So as there are problems, so are there their solutions. But approach clearly is not like - I wanna X and nothing else, but what useful things I can have out of what I can do and which one I'll be having today.

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    $\begingroup$ This explains very well why Venus is a good source for material exploitation. It does not at all delve into why landing humans on the surface is at all required. Humans are squishy, and do not do well in that atmosphere, at those temperatures. $\endgroup$
    – PcMan
    Aug 26 '21 at 10:15
  • $\begingroup$ @PcMan correct, I didn't manage to find a reason for human landing, even if I state that technologically such possibility does exist with perma-base if necessarily. it can be considered as a no-answer, or at least I found reasons to get them sufficiently close(in orbit). Maybe they spot something which picks their curiosity or necessity - not enough fantasy on my side/I just hope it fits helps in "Politically and economically stimulating" and/or "any and all answers.". Your objection is 100% correct, and honestly, I forgot about that XXX requirement and was more - do they have reasons at all. $\endgroup$
    – MolbOrg
    Aug 26 '21 at 11:52
  • $\begingroup$ so it is just a no-answer, or frame challenge, that any help I can provide - as I do think that Venus is significantly underrated, and advocating for it is a good thing. But landing, humans, eeeh it puzzles me why one would need it. Can you - yeah, will you - yeah, but need it - no idea. $\endgroup$
    – MolbOrg
    Aug 26 '21 at 11:54
  • $\begingroup$ @MolbOrg Upvoted anyway for good initial setup of why going to Venus in the first place is economically viable. I can work with that, it'll give me some reason to put some humans in orbit supervising the automated machinery. They find something on the surface from a drone camera and decide to go take a look. $\endgroup$
    – Lelu
    Aug 26 '21 at 15:36
  • $\begingroup$ @Lelu yes, it was my intent to give you some a bit more feasible fundament, towing them further down the surface is most likely up to you and the story. SPQR for the Venus. $\endgroup$
    – MolbOrg
    Aug 26 '21 at 18:07

The motivation could be the planet itself. Suppose they decide in the future to terraform the planet how could they do it? Process the atmosphere starting from above from some balloons or airships? It would take too long. Another solution could be to send some robots designed to work under high pressure, with every void inside filled with oil. The robots could build some underground tunnels which could be sealed to created a living space and people could work from there. Then people and robots could extend the underground bases, mine for minerals and, at the same time, process the thick atmosphere.

  • $\begingroup$ The pressure is equivalent to an ocean depth deeper than that experienced by any hard-shell atmospheric diving suit, and the temperature is high enough that lead melts and aluminum alloys are about as structurally sound as butter. Oil will vaporize or turn into tar. We can just barely make very simple electronic circuits function at those temperatures, any brains or power electronics (or humans) will need to be in vacuum-insulated vaults with heavy, power hungry active cooling. Those underground tunnels will be just as hot as everything else. $\endgroup$ Aug 26 '21 at 23:59

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