In a story I am writing there is a being with Superman level strength, flight, the ability to produce lasers, and survive in space. He has decided to solve the mineral crisis by finding and grabbing an asteroid and taking it back to earth so that it can be used to build lots of cool things and green tech.

They have the backing of an eccentric billionaire, and moderate political will in support of them, and modern earth technology.

How would they best, with brutal physical strength, flight, and lasers get that mineral wealth from space to earth?

Some constraints- they can, essentially forever, produce 200 megawatts of power for use in flight or lasers.

Their flight doesn't require notable reaction mass.

They are durable enough to survive space and high accelerations essentially forever, and air isn't a concern.

They don't have magical forcefields to make asteroids stay together or behave.

Ideally, humanity will be functional as a civilization by the end, with no world ending impacts. Props to any answer which involves less loss of human life, or none.

To summarize- how could a being with 200MW of power eternal best harvest asteroids?

Edit. As JBH noted, science based questions don't have to have fully plausible scientific questions, the answers have to be plausible. That said, you can replace the superman with a 200MW fusion spaceship if you prefer with lasers and flight.

  • $\begingroup$ How does the superpowered being move around in space? Do they have a magical movement force, rocket boots, or what? $\endgroup$
    – Bewilderer
    Jan 23, 2019 at 22:25
  • $\begingroup$ They can harvest materials from around them and use them as an ion drive, powered by fusion power. So long as they have a reasonable quantity of water around they can keep doing things. $\endgroup$
    – Nepene Nep
    Jan 23, 2019 at 22:26
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    $\begingroup$ This Scenario is way too fictional and unlogical to give a proper sience-based answer. This "Superman" is far from explainable, why should the methods be? I find your approach a bit... inconsistent. $\endgroup$
    – miep
    Jan 23, 2019 at 22:47
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    $\begingroup$ ATTENTION DOWNVOTERS! The science-based tag refers the nature of your answers, not the premise of the question. We regularly entertain questions with dubious (read: absolutely ridiculous) premises. The OP doesn't need to justify the premise to his question - you only need to justify your answer based on the restrictions of the question. Please remember to be nice. $\endgroup$
    – JBH
    Jan 23, 2019 at 23:27
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    $\begingroup$ I feel like any proposed solution will probably be less efficient than doing as suggested in this comic: smbc-comics.com/comic/2011-07-13 and then using the energy towards whatever normal means of mining people would do if they didn't have a superman. $\endgroup$ Jan 24, 2019 at 9:11

7 Answers 7


There's good news and bad news. First... the bad news

The lasers are almost useless

Have you ever picked up dirt clods with your hand? Have you ever picked up a lot of them? It's a slow process. It wouldn't matter how super-strong or super-fast he is, anything's more efficient than picking up dirt clods — and that's what lasers would make of the asteroids, dirt clods.

The only reason to use them is to quickly knock away huge chunks of less-valuable rock to get at the more-valuable rock.

However, if there's so little valuable material in asteroids that you're regularly knocking off huge chunks of less-valuable rock, then using the super strength to get stuff out of the ground of good old Earth would be more efficient. Remember, it takes time to get to asteroids.

But, there's good news!

Your superperson can haul a net. A big, honking netObligatory XKCD made out of steel cable. A net that would allow him to haul a whomping big bag 'o asteroid home with him. This is good, because 200MW will haul almost any amount of asteroids home. The problem isn't getting them back to Earth orbit.

It's getting them down from Earth orbit.

Maybe the lasers have value after all...

How much energy do we have to work with? Let's do some quick math. Let's assume superdude's a buff and beautiful 235 pounds (106.6 Kg). He's gotta go 7 miles a second (11.3 Km/s). OK, F=mA, we need 1.2e6 Newtons of force. Basically, newtons = watts, so 1.6MW are needed to get up and he'll need the same to get down unless he's planning to land in the ocean or make a hole someplace.

That gives us 198.4MW to work with. That means he can land 13.2 metric tons of material. The price of gold will plummet.

And that's really good news! Well... not the price plummeting part...

What this means is that superdude can put the bag 'o asteroids into orbit, then shuttle 13.2 metric tons of it down at a time. All he needs is (literally) a world-class net or bag.

My father would be proud! I got my money back and nobody got [hurt]. (Source)

  • $\begingroup$ I feel this answer works best, as it suggests a clear and practical methodology towards picking up asteroids, with respect to the composition and the entire journey from asteroid belt to earth. $\endgroup$
    – Nepene Nep
    Jan 24, 2019 at 11:34
  • $\begingroup$ I think the biggest problem is kind of the opposite one: having the asteroids land without causing the equivalent of a nuclear explosion every time? If the asteroids are as small as a few hundreds meters in diameters, that would still create a crater a few kilometers wide. And if you also consider the depth, you probably don't want them to always land in the same spot. $\endgroup$
    – ChatterOne
    Jan 24, 2019 at 11:54
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    $\begingroup$ The answer suggests you simply ferry the mess down, 13 tons at a time. $\endgroup$
    – Nepene Nep
    Jan 24, 2019 at 11:58
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    $\begingroup$ Incoming 2019-style nitpicking: the question mentions Superman-like powers but does not constrain the gender of the individual who wields them (in fact using gender-neutral language throughout, presumably deliberately), whereas this answer assumes a male hero for some reason. What about Supergirl?! $\endgroup$ Jan 24, 2019 at 13:05
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    $\begingroup$ @JBH got it now, i wasn't fully onboard with your stuipulation that the gravitational acceleration was to be considered equally to the 'usual' accelaration - but with that as a given (i.e. superman may or may not be able to hold any weight at constant height, but as soon as the weight is being lifted or lowered, Work is being done, with a rate of Power. As for the five year question: It was only relevant if gravitational acceleration was being disregarded, i wanted to make 'usual' acceleration very small to makke a point about rate. $\endgroup$
    – bukwyrm
    Jan 29, 2019 at 8:28

The best way to solve the mineral crisis isn't to get the asteroid to Earth but to get the equipment from Earth into space to allow the harvest and processing.

The cost of getting materials into space is around $25K a kilo. If Superman provided an cheap taxi service to get people and materials into space, people could go get their own asteroids.

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    $\begingroup$ Good idea. What equipment would be best to bring up, and where abouts should they put it? $\endgroup$
    – Nepene Nep
    Jan 23, 2019 at 23:49
  • $\begingroup$ Far Earth orbit where you can use things like ion drives to escape orbit and travel out to the asteroid belt. As for things to bring up, the first thing needed is a rotating space habitat (think 2001 a Space Odyssey) and then zero G smelters $\endgroup$
    – Thorne
    Jan 24, 2019 at 0:02
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    $\begingroup$ To add to this answer I think Superman should help construct a space elevator. That way he doesn't have to personally attend to every single vessel attempting to exit/reenter Earth's atmosphere. $\endgroup$ Jan 24, 2019 at 6:35
  • $\begingroup$ Its more like 10k - 15k per kg to launch, with F9 coming as low as 5k. $\endgroup$
    – Polygnome
    Jan 24, 2019 at 8:31
  • $\begingroup$ If we could transfer stuff to orbit for almost-free... have giant orbital power arrays beaming power down to rectenna's, industrial plants in orbit with giant mirrors to melt asteroids and process them.... it's a fair bet that having out superman fetch the asteroids might be the least efficient use of his time vs shuttling from ground to orbit. Never mind the countless other interesting things possible if it's cheap to get things into orbit. $\endgroup$
    – Murphy
    Jan 24, 2019 at 14:52

Supernaut - How to cheat at Space Exploration

Supernaut is functionally free Delta-V with a brain.
He can easily go anywhere in the solar system without any additional equipment and carry a payload with him, that's fantastic in every sense of the word.

The best thing Supernaut can do is learn the engineering requirements to maintain space hardware so he can just go out and deal with ad-hoc problems without a multi-billion dollar expedition.

Even without specialist knowledge, our super-astronaut provides the incredible service of being able to physically go fetch defunct or damaged satellites and bring them home for repairs before putting them back.

If you're not keeping him busy with big projects, Supernaut can easily go land instruments and equipment on practically every body in the solar system, you want to know what that bright shiny spot on Ceres really is? He can go fetch a sample of the water-ice there and bring it back for your coffee.
He can physically carry a box containing a mars rover, set it on the martian soil, open it and leave again. No more huge rockets for tiny payloads.
Cubesats? He can carry a crate of them and deploy them anywhere in the solar system for free.
Supernaut can very easily go prospecting for useful minerals and bring back samples so you can decide whether mining there is worthwhile too.

Supernaut's spare time can be filled accelerating fuel and cargo pods into Hohmann trajectories to resupply missions throughout the solar system. Essentially free Launch Delta-V means that they can simply carry enough to perform their deceleration at the other end and rendezvous with whatever they're there for.

What about Asteroid mining?

With the savings on the smaller missions, nearly all the budget can go into the construction of a modular mining spacecraft which Supernaut can carry in sections and help assemble in orbit.

The actual flight to the asteroid can be conducted conventionally with the ship running uncrewed on automatic, our Supernaut can then ferry the crew in a small car-sized passenger module and take far far less time to do it.
This negates most of the challenges of keeping a crew alive for the months it might otherwise take to get to the asteroids.
Remember that Supernaut can be under power continuously the whole time, a week at most to rendezvous with the mining ship in a craft comparable to the Apollo Orbiter is pretty acceptable.

If sending a crew to mine asteroids doesn't appeal though, you can still have Supernaut ferry boosters out to the target asteroid so it can be pushed into a more accessible orbit remotely. Having Supernaut do the pushing will be long and tedious compared to setting up something more slow-burn and leaving it alone.

In Conclusion

Asking Supernaut to physically mine or even to fetch asteroids would be a staggering waste of potential.

Really your only concerns as NASA Administrator is in keeping Supernaut happy and busy. Pay him whatever he asks, because it's bound to be cheaper than doing things conventionally.

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    $\begingroup$ Very good! Lateral Thinking. $\endgroup$
    – bukwyrm
    Jan 25, 2019 at 14:44

Okay, so according to this article, the rotation needed to break apart the average asteroid is equivalent to one revolution every 2.2 hours. Doing some quick math, I found that the maximum acceleration an asteroid could withstand under these parameters without breaking up is 8.157 * [asteroid radius in meters] meters per hour squared, or 0.000000629 * [asteroid radius in meters] meters per second squared.

To put that in perspective, if the superpowered being wanted to move the largest known asteroid, Ceres, with a radius of 476 km, the maximum acceleration that it could receive is 0.299 meters per second squared. Considering Ceres is about 2.77 AU away from Earth (4.1439 * 10^8 km), it would take 1664880 seconds to move it to Earth (about 19.25 days). However, at the end of this, it would be moving 497799 meters per second (0.001 of the speed of light).

If instead the super hero went out and got the smallest known asteroid, 2012 DA14, with a radius of 10 meters, in 2013, when it passed within 27000 km of Earth, the maximum acceleration would be 0.00000629 meters per second squared, it would take 2930030 seconds to get here (about 34 days), and it would be moving only 18.430 meters per second when it got here.

So, in conclusion, if your superhero wanted to transport an asteroid, they would either be able to safely get not enough material here, or get a sizable quantity of material at a far too dangerous speed.

  • $\begingroup$ Umm, for your Ceres example, you're ignoring the fact that (if he has any knowledge of orbital mechanics at all), he will switch to decelerating upon reaching the halfway point, which would allow him to stop exactly upon reaching the destination. This is known as a Brachistochrone trajectory. $\endgroup$
    – Gryphon
    Jan 24, 2019 at 0:58
  • $\begingroup$ @Gryphon oh, right, I forgot about that. I will recalculate arrival times when I get the chance to calculate the force required to counteract the Earth's gravity and then put Ceres into orbit. $\endgroup$
    – Bewilderer
    Jan 24, 2019 at 1:00
  • $\begingroup$ What type if tides would you get with Ceres now in orbit of the Earth? $\endgroup$
    – Sonvar
    Jan 24, 2019 at 5:35
  • $\begingroup$ You've not taken into account that you don't need to move ceres straight-line, you need to apply Delta-V. It's around 5km/s of Dv between LEO and Ceres, the 2.77AU is largely irrelevant. So at 0.299m/s per second of acceleration, it'll take you around 4 hours and 45 minutes of constant pushing to get Ceres into an atmosphere-grazing intercept with earth,This is a Bad Idea, you'll definitely want to be decelerating at the other end! I don't have the math to work out the flight-time though. $\endgroup$
    – Ruadhan
    Jan 25, 2019 at 17:12

An individual is going to have a very hard time harvesting asteroids even if they are super powered. It would be better if they just redirected a bunch of asteroids towards earth, moved them into stable orbits then lowered them all onto the planet.

That way, he only needs to travel back and force once between the asteroid belt and earth to deliver many asteroids, and by lowering the asteroids back to earth, he can retain all the current mining and manufacturing equipment which will be able to process the materials in the asteroids much better than any single human would be able to do.

He just does the hard part. Getting that comet that could wipe out the planet from space and into the hands of industry.

As a bonus, he could also dump all the waste materials on the planet into the sun for much cheaper than rocket launches and since he can replenish the material we dump into the sun, we don't need to worry about running out of resources (until our super hero leaves or gives up).


Working with simplified physics, 720GJ per second, after 10s and disregarding gravity, assuming 90kg... 7200GJ=45kg*v^2 => v = sqroot(7,200GJ/45kg) or 4Mm/s or slightly over 0.001c

That means they can move fast.

Realistically, physics gets wonky at high speeds. Maybe they could use an array of space mirrors to melt asteroid surfaces and change their orbits. Maybe they could fly out to the asteroids and change the orbits there. Really, it depends on far too many factors: how much food they need, how far the target is, how much mass the target has, the velocity vector of the target, the technology available to the civilization, and so forth.

I recommend not explaining whatever madness you are angling towards here and leaving it up to the reader-- or just having them sit on some electricity-generating bicycles. It'd be a lot simpler...

  • $\begingroup$ A 200MW exercise bike would truly be something to behold! $\endgroup$
    – Cort Ammon
    Jan 23, 2019 at 23:19
  • $\begingroup$ @CortAmmon - more likely it'd be a treadmill $\endgroup$
    – jdunlop
    Jan 24, 2019 at 1:35
  • $\begingroup$ I think you may have upped their power a bit, the baseline was 200MW, and my own rough calculations show they'd only be able to accelerate around 2km/s^2, but regardless, yes, they are fast. 200MW is useful, but not an appreciable amount of a power grid. $\endgroup$
    – Nepene Nep
    Jan 24, 2019 at 3:19
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    $\begingroup$ Related: smbc-comics.com/?id=2305 $\endgroup$
    – mrienstra
    Jan 24, 2019 at 7:23
  • $\begingroup$ @NepeneNep 200MW may not be much on the powergrid, but nor is it much compared to the power output of various rockets we use to send things into space. $\endgroup$ Jan 24, 2019 at 9:27

Have your superman use his strength and/or lasers to produce electricity, and then use that energy towards whatever normal means people in your world would use to mine asteroids in the event they didn't have a superman to assist them. Even if you don't have a way to launch things into space with electricity, you can probably use that electricity to produce everything needed for the rockets and so forth.

Some other answers suggest having superman carry stuff into orbit, but he's going to be slow at it. You said he has 200MW at his disposal, but the power output of a Saturn 5 rocket is in the 83,808MW range (111,744,000 hp * 750 watts/hp) https://www.quora.com/What-was-the-horsepower-and-torque-of-the-Saturn-V-rocket So, he could do it in theory, but more slowly, and only one at a time.

This has the added benefit of not making the mining operation completely dependent on superman should he be temporarily needed for some other more pressing task like saving the world, and any technologies developed to do the mining can then be scaled up as new energy sources become available.


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    $\begingroup$ He does have the advantage of not having to lift two million litres of fuel along with his payload though, so his power output can get away with being considerably lower for the same payload mass. $\endgroup$
    – Separatrix
    Jan 24, 2019 at 11:21
  • $\begingroup$ As much as I love SMBC, 200MW is a small power station, he won't make a serious dent in anyone's power needs. Sweden alone used 20TWh just for steel production in 2013, so lobbing things into orbit is still a better bet as it's a limited skillset. $\endgroup$
    – Separatrix
    Jan 24, 2019 at 11:29
  • $\begingroup$ @Separatrix I agree that it's not a massive amount of power. But because it's not a massive amount of power, it's similarly not that useful for hauling things into space. Sure, he'll be able to, but he'll get a lower acceleration and take longer to do it than a rocket would have. And there's only one of him. So if the planet is interested in doing space mining at scale, his contribution will be minimal. $\endgroup$ Jan 24, 2019 at 18:49
  • $\begingroup$ @Shufflepants Math says Supernaut can pull 53g of acceleration without a payload. He can certainly lift upwards of 10 tons of payload at a time into orbit and do it with twice the peak G-forces of the Apollo missions. If you want to go to mars, he can get you there inside of a week and carry a camper-van sized payload with him. There is no way that's not going to be a total game-changer for any space-program. $\endgroup$
    – Ruadhan
    Jan 25, 2019 at 17:19

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