For the sake of simplicity, my species is similar to humans but far more advanced. We will also assume that they live in a solar system similar to ours, and that they are advanced enough that they can 'catch' an asteroid and land on it.

These people wish to create a research base which orbits the sun, not the earth. To do so, they are planning to build a base on an asteroid. Assuming this asteroid has a similar orbit to the one shown below, what would this research station look like?

Asteroid orbit

People would be transported to the base on rockets, and to get back to 'earth' they would eject a pod while the asteroid is travelling towards the planet and drift back home (again, assuming very advanced technology).

The asteroid they have chosen is large (about 900-1000 km diameter) and is made from a combination of carbon compounds, iron and magnesium silicates, nickel, igneous rock, and ice (all in abundance). Its gravitational field strength is around 1/32 of earth's. With an orbit like above, the speeds and temperatures on the surface would be difficult to deal with.

Assuming my race of sentients can land on an asteroid like Ceres, with an orbit similar to Phaethon, what would their asteroid base look like? How would it be operated and what sort of systems would it use? They need to be self-sufficient (produce food) and be able to survive both extremes of the asteroid's orbit. Assume advanced technology, but nothing unrealistic (no time travel, teleportation, or artificial gravity please)

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    $\begingroup$ something to bear in mind, each launch and landing will change the mass of the asteroid, potentially sending it into the sun. Each launch and landing will need to be counterbalanced $\endgroup$
    – Chris J
    Commented Aug 19, 2016 at 10:14
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    $\begingroup$ @ChrisJ That is a good thing for people to consider in their answers $\endgroup$
    – Aric
    Commented Aug 19, 2016 at 10:15
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    $\begingroup$ Ceres gravity is 0.028 of Earth's, with similar diameter. How are you planning to have your asteroid have similar size, kinda similar composition, and ten times stronger gravity? $\endgroup$
    – Mołot
    Commented Aug 19, 2016 at 10:45
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    $\begingroup$ One thing to bear in mind is that even if you time your return transfer window perfectly, you'll have an awful lot of orbital velocity to shed in order to not escape Earth. Earth does have a nice atmosphere that you can use for aerobraking, but the approach angle required to capture an object moving on such a highly eccentric solar orbit is probably not very healthy for the reentry craft. Which is to say that you will probably explode (and rather quickly, at that.) Might need to plan a slingshot maneuver or two to help burn off excess energy, plus pack some fuel and propulsion. $\endgroup$
    – Dan Bryant
    Commented Aug 19, 2016 at 16:58
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    $\begingroup$ To rephrase it in a perhaps more visceral image: it's like you're trying to hitch a ride on a train by jumping in front of it and catching it as it runs into you, except the train has the mass of the Earth and it's moving at 30,000 m/s directly toward your face as you move sideways past its direction of motion. $\endgroup$
    – Dan Bryant
    Commented Aug 19, 2016 at 17:05

5 Answers 5


Some consideration has to be made abut the composition of the asteroid. If it is a solid mass, then you will essentially be tunnelling into it like the NORAD bunker in Cheyenne Mountain. However, current theory suggests that asteroids are loose piles of rubble with lots of spaces in between, so the interior of the asteroid is almost like a sponge. A very large asteroid such as you describe could have a very interesting composition. Some of the data from Ceres seems to suggest there is a lot of water trapped inside.

Regardless of the composition, once you have burrowed inside, you will have very little gravity. Creatures evolved on a planet would prefer some simulation of gravity, both for health and comfort, and because it makes working easier (tools don't float away, for example). So the space inside should be cleared enough to build a rotating space station that provides a gravitational simulation.

This concept can be expanded to create what is known as a Gravity Balloon. The concept is explained in detail at the link, but the explanation is simple. A large enough space is found or excavated, lined with an airtight membrane and filled with air. Tension cables are strung along the interior, and rotating structures strung along like beads to provide the living space where a simulation of gravity is created.

enter image description here

The rotating structure everyone lives in

This illustration would be for a very ambitious colony, an external mirror transfers sunlight into the interior and the small black dots are rotating structures 500m in length to give you an idea of scale:

enter image description here

Most of the other details of day to day operations can be gleaned from sites like Atomic Rockets, and many of the other posters have mentioned many of the factors needed to operate in space.

  • $\begingroup$ Even though i said "no artificial gravity", this idea seems plausible. Also i like the way the chamber is cone shaped to allow for a gravity gradient as you walk along it. $\endgroup$
    – Aric
    Commented Aug 19, 2016 at 13:10
  • $\begingroup$ As regards to zero gravity however, they seem to do ok on the ISS... You could possibly have an 'ant's nest' design dug into the asteroid... The minimal gravity would let people float down the tunnels, and you could make it airtight to contain an atmosphere inside it. $\endgroup$
    – Aric
    Commented Aug 19, 2016 at 13:27
  • $\begingroup$ @AricFowler it depends on how long your crew will be there, following on from the tours on the ISS there is a weakening of muscles as they have so little to do. Also gravity is nice to have so you can do things like use the toilet normally and not worry about your tears forming big watery balloons on your eyes $\endgroup$
    – Chris J
    Commented Aug 19, 2016 at 15:10
  • $\begingroup$ @ChrisJ Considering that the orbit of such an asteroid can take several years, i think it would be wise to have gravity then. Otherwise you're going to be stuck in zero gravity for a looong time, slowly wasting away..... $\endgroup$
    – Aric
    Commented Aug 19, 2016 at 15:12

Underground base

The base will need to be underground to provide protection from radiation. Even just being in Earth orbit is a major radiation hazard when the solar wind is heavy. The reason we do not fry here on the ground is because the Earth's magnetic field and its atmosphere protect us.

enter image description here

These pretty lights are where the atmosphere blocks particles that would otherwise kill you through severe radiation poisoning

Your asteroid has no atmosphere and no magnetic field worth speaking of, and it goes into the very "stormy" regions of the solar system, right next to the Sun. By the look of that diagram, it even passes close enough to touch the corona.

This means the radiation hazard is extreme. If this base is sweeping that close to the Sun, they will need very heavy radiation shields.

Best way to do that would be to 1) bore down into the asteroid, since stone and metal-rich minerals protect very well, and 2) place the water tanks between themselves and the Sun. Water is an excellent radiation shield.

enter image description here

The major danger of taking a swim in a nuclear fuel pool is that the guards will be very cross with you for contaminating the ultra-pure water in the pool, you filthy thing you

So the main distinguishing feature of your base is that it needs to be underground.

All work sites related to this base will need to be underground as well, or be shielded, or have radiation hardened bunkers nearby where people can go when things get "hot".

This was a concern on the Apollo missions when — on the later, long duration J-type missions — the astronauts went for long treks on the Lunar Rover. NASA was very nervously watching the Sun for activity, because if the Sun had flared, Mission Control would have needed to recall the astronauts and have them take shelter in the Lunar Module to protect them from the resulting radiation.

With this I would expect the base to have one or several dedicated tunnel boring machines in operation.


Fusion reactors. Someone else suggested solar panels but I digress on that. Solar panels are extremely heavy compared to the power they give, and when you travel in space, you want to keep things as light as possible compared to the amount of "usefulness" they provide. If your heroes are "far more advanced" than us, then just assume they have mastered fusion instead. Energy is probably a non-issue.

enter image description here

Bring your handy fusion reactor, and energy will not be an issue. Plus you have a very sci-fi looking element of your futuristic base. (Source)

Water, air

This will need to be brought, or — if they bring an extra fusion reactor — they can break apart materials on the asteroid to form these on site. Hydrogen is everywhere in the universe, and so is Oxygen. You just need energy to break apart minerals and molecules to form the right stuff.

After the edit to the question: If there is ice on the asteroid, this is a non-issue. Use the fusion reactors to melt and purify the ice for water; use electrolysis to make Oxygen from the water.

Purification and re-circulation of waste water / waste air will probably be necessary.


Expect that to need to be stockpiled. Unless of course — like air and water — you expect to be able to manufacture that on site. But unless your heroes have Star Trek type replicators it will probably be quite boring food... rather simple nutritional pastes and fluids, simple sugars.

Do note that this makes for a nice plot element when the transport from Earth comes with the good stuff... steak, juice, drinks. Also note that during the perihelion (passage closest to the Sun), no transports can come... the radiation is too heavy. And there is probably very little work to do during perihelion since they have to huddle in the radiation proofed areas of the base, sucking on their protein pastes and mineral-supplements.

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    $\begingroup$ +1 for scientific precision and explainations about solar panels. Excellent answer there. $\endgroup$ Commented Aug 19, 2016 at 11:53
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    $\begingroup$ what about growing plants using water and air? you can get carbon and minerals from the asteroid itself... maybe grow the plants hydroponically? $\endgroup$
    – Aric
    Commented Aug 19, 2016 at 13:09
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    $\begingroup$ @AricFowler Do note though: nitrogen is important here. Plants need that. Where are you getting the nitrogen? $\endgroup$
    – MichaelK
    Commented Aug 19, 2016 at 13:31
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    $\begingroup$ Technicality in your excellent answer: orbiting the sun it would be perihelion, not perigee. The base word for any orbit is periapsis, but the suffix is changed based on what body you are orbiting - gee for Earth, helion for the sun, and others for other bodies. See en.wikipedia.org/wiki/Apsis $\endgroup$
    – Cody
    Commented Aug 19, 2016 at 21:15
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    $\begingroup$ @MichaelKarnerfors wait till you make it out to Jool, its fun playing gravity assists with the 3 inner moons $\endgroup$
    – Cody
    Commented Aug 19, 2016 at 21:26

(First answer ever here, I'm not sure to be specific enough)

Survival will be hard. Asteroids having no atmosphere, your base should be able to resist very high temperatures, nothing stopping the energy from the sun they orbit around to get directly to your base. You would also need some heavy energy-absorption systems and ventilation if you do not want your base to hold some human barbecue. Those conditions are necessary only if you want an orbit similar to Phaethon, which passes very close to the sun at some point.

Assuming very advanced technology, they could build some kind of railway building very quickly, in order to dodge going close to the sun. It would automatically adapt to get to the opposite face when it goes near the sun, and facing the sun when it is far enough. Detection systems like antennas or anything could do this positionning decision trick.

About the look of your building ... It is all up to you. The only restriction I would give you is to make it as flat as possible. The composition of your asteroid makes me feel like a huge building will have a rough time getting solid foundations, and the speeds there will be tremendous for it to bear. A maximum of one floor, maybe ? I don't know, but make it kind of flat. In my vision, it would greatly ressemble houses from Dragon Ball Z ? This way, you'll divide the weight of your building throughout the asteroid's surface, and won't have to think about very deep structures.

For the deployment, you have advanced technology. Automatic building deployment could be a thing, as it already exists in some extend. You could improve it to make automatic foundation digging (careful, not too deep) and room-repartition deployment. It lands, it deploys, humans can come and go.


Energy is not a problem, you have the Sun. Solar panels will absorb the energy for you and feed the electrical system. So you have power to keep your food nice and cold, until it is consumed.

I doubt any prey for humans would live there naturally. You would have to transport it from your "main planet". I think lyophilized food will allow you to transport a lot of food, so you can limit your transport cost. Your base should plan some kind of landing field, so you can get both humans and supply to come (and go) to your base.

If they want to go back to base, there are numerous solutions. A small number of humans may be able to go for it through escape pods, be it classical propulsion or heavy-calculated launch through space to Earth. If you want to leave entirely, the building would have, of course, some "zipping" functionnality (as you deployed them). Call the Earth, tell them you are all planning to leave. Send the equipment first, then most of scientists, then a space ship could come and take back the building and the few engineers staying.

  • $\begingroup$ Food is also a concern. How will the base run? Where will they get food and how will they generate electricity? What sort of system would they use to launch back towards 'earth'? $\endgroup$
    – Aric
    Commented Aug 19, 2016 at 9:55
  • $\begingroup$ I will try to elaborate. You asked for that the base will "look like" :p. $\endgroup$ Commented Aug 19, 2016 at 9:55
  • $\begingroup$ Yeah i realised... I didn't mean to say that haha $\endgroup$
    – Aric
    Commented Aug 19, 2016 at 9:56
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    $\begingroup$ Asteroids usually rotate too fast for a moving building to be useful as a protection from the sun. See Michael's answer for an alternative. Other than that, nice answer, +1. $\endgroup$ Commented Aug 19, 2016 at 11:07
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    $\begingroup$ I'm accepting every constructive criticism. Seriously, you guys here are way more kind that on StackOverflow. Thanks @MichaelKarnerfors for the feedback, did not think about being sufficiently far away to not be able to "farm sun". $\endgroup$ Commented Aug 19, 2016 at 11:51

Wait wait wait... While resources and stuff has been addressed already (I'm voting for fusion reactor btw.... I wonder if you can grab/soak/inhale new fusion material while drifting through suns corona...) something just spoke of in a comment @Dan Bryant and @Euphoric is pretty vital to the whole story.

Rendezvous with the asteroid

so... I do not know what kind of future advanced technology your civilization does own, but if they cannot offer vessel that has a deltaV of... huh...

  • remove earth-velocicy (30km/s)
  • correct ascending node and perihelion (about 5km/s?)
  • rendezvous burning (5km/s?)
  • and back: remove orbital speed of base-asteroid at earth' semi-major-axis (hm... 5km/s?)
  • gain earth orbit velocity (30km/s)
  • break to decent back to earth (7km/s, while here much aerobraking can be done)

means about 80km/s deltaV... ehm, deltaV is the total change of speed of a spcecraft provided by its engines (and fuel niveau). Okay, these are estimates beyond any calculation, so maybe the real number is even bigger.

Thats pretty insane. The only useful alternative would be a Hohnmann-Transfer to the asteroids aphelion and than a braking burn, which would be quite fuel efficient. Still, thats beyond today capabilities, and even if you could do this, you only have a narrow timeframe every year when the transfer would be most efficient (I would guess when the earth is at the suns other side).

So as long as your spacecraft arn't capable of these stunts, please go for a more relaxed asteroid.


Okay... half the distance of Mercury? Did you bring some insane cooling radiators with you? Don't think a lump of rock will keep you cool enough when coming this close to sun. While you will have the energy to fuel this, you need some real batshit engineered apparatus to get rid of excess heat.

Cooling Doesn't sound so fancy, but without an atmosphere to carry away heat, all you have is blackbody-radiation, which need huge surfaces to work properly. Surfaces that shold not point to the bright, warm thingy that will cover up half of the visible sky. So no asteroid rotation or the cooling apparatus needs to be even more interesting.

Station keeping

Last but not least - you are passing through suns most outer part of atmosphere... A T M O S P H E R E. every time you are at the closest point, you will loose some momentum due to friction. When not accelerating the whole asteroid one day in future even the best heat-radiators won't keep you cool any more.

So... yeah, there are plenty of cute asteroids out there which don't require such an effort to went to. if there isn't any really fine stuff located at that heap of stone and metal, leave it be alone.

Plane Shift

That's the second edit about something I forgot in the beginning: That astroid needs to be at a pretty inclined plane compared to these of the other planets; because he is passing at least four other celestial bodys during his orbit (which are all in the (way) > 10e22kg mass range) all of them would be able to throw him into the sun or make him a runaway when he comes inside their sphere of influence. Or just plain crash (which is highly unlikely but still an valid option).

What does this mean? Not only you need to arrange with that eccentric orbit, you need to adjust to a probably insane inclined plane, which is even less of a pleasure to compute.

EDiT: I have to admit, the latest comments made me think... advanced technology may be able to convert even the heat gained by the close distance to sun into thrust... just funnel this to a point where some kind of expanding propellant is stored. Hell, you could get thrust by applying microwave laser to your most retrograde part of that rock; the surface melting and subliming away will provide forward momentum (but how much... and one day our asteroid will be... used). The skyhook... wiki says you get about 3.5km/s in theory. Still missing 60km/s. This comes down to pure math. Which I'm not good at. If you employ a mass-driver for spaceships you might be off better.

If your spaceship can use any form of an ion drive (or something similar) than reaction mass (and ship mass difference between dry and wet) would be a negligible problem, but you need aeons to apply the thrust.

I'm still for an asteroid in a much nicer orbit ;)

  • $\begingroup$ Using thermal energy storage could they perhaps store heat from the sun for heating when in the outer reaches of the solar system, and then reduce their temperature by absorbing heat again while close to the sun? Apparently, seasonal thermal energy storage is the storage of heat or cold for periods of up to several months. Could this work? $\endgroup$
    – Aric
    Commented Aug 22, 2016 at 11:18
  • $\begingroup$ Perhaps a skyhook or two could solve the acceleration/deceleration... Remember that we are assuming advanced technology beyond our current understanding! $\endgroup$
    – Aric
    Commented Aug 22, 2016 at 11:23
  • $\begingroup$ The Hohmann transfer window is when departing the apoapsis of the asteroid's orbit with the right velocity to set the new solar orbit periapsis to coincide with Earth would also cause the return vehicle to get to that point at the same time as Earth. There will be a particular phase angle between the Earth and the asteroid orbits where this transfer is possible. In other words, you don't throw the ship at the Earth, you throw the ship at where the Earth will be, but so it also coincides with roughly the direction it's moving at the time. You try to best match position and velocity. $\endgroup$
    – Dan Bryant
    Commented Aug 24, 2016 at 20:46
  • $\begingroup$ @DanBryant, if you can afford inefficient thrusting because of an abundance of deltaV, they might be able to "jump off" the asteroid and waste propellant as long as necessary until they (first) got rid of the asteroids inherited orbital velocity and (second) got earth velocity and (third) changed their plane to that of earth... when reading this, that sounds ridiculous. Shifting between these two bodys in an efficient way would include some pretty gravity-assist-dancing and years of flight-time, wouldn't it? $\endgroup$ Commented Aug 25, 2016 at 6:21
  • $\begingroup$ Gravity assists can help make it more efficient, but a Hohmann transfer will still be pretty efficient if you can tolerate a year or so of flight time, as well as waiting a few years between transfer windows. If you have extra delta-V, you can widen the transfer window and get their sooner by deliberately intersecting Earth's orbit at less favorable approach angles, which also means extra delta-V required to enter orbit. This will still be vastly more efficient than the sideways approach, which, as you stated, requires achieving almost the entire orbital velocity of Earth from scratch. $\endgroup$
    – Dan Bryant
    Commented Aug 25, 2016 at 13:21

I'm going with the simple idea, that there wouldn't be a base in an asteroid at all unless it served another purpose than just 'research'.

That purpose could be anything from surveillance, where the asteroid might be span to produce 'gravity', to a military installation with a mass driver, to a factory that produced high tensile strength cable and lowers it onto planets for a relatively mobile space elevator / counterweight in one. whereby the base would stay in a stable geostationary orbit for a time.

Much of the equipment on board would depend on the purpose of this asteroid base. I mean, what does an asteroid base in a fairly erratic orbit provide that the ISS cannot do in the real world?

I don't see any logical reason why any 'intelligent' species would just build a base in an asteroid with such an orbit. Unless the goal is to obfuscate their goals they'd capture it and put it into a more stable orbit, probably mine it for raw resources.

Food's easy: multi-level robotic greenhouses.

Water is easy, they already have ice.

Radiation protection comes from the thickness of the rock and some extra gold foil around the viewing areas.

For power, I'd assume that this species would already have solar panels in orbit, and can laser the energy into the base. No weather, no day night cycle, affordable and infinite. Heck, maybe the asteroid base is a maintenance station for the species' new dyson swarm.

Gravity is trickier, either spinning it or constantly accelerating it, either one provides problems that are fairly intuitive.

Controlling the asteroid shouldn't be too hard, solar sails are surprisingly effective (both cost and usability), and can even be designed to allow for tacking and beating toward the sun.

Keeping that orbit would only help if the goal is to:

Survey something inconspicuously.

Attack something unexpectedly.

Maybe the base is nothing but a giant flywheel, and your species is moving it into a more stable orbit in order to:

Turn this base into a counterweight for a space elevator.

Mining for rare metals

space-based construction of solar panels

other goals, like tourism, are equally applicable to either one, but a more steady orbit would help people arrive and leave.

  • $\begingroup$ Hi, welcome to worldbuilding! This question refers to an advanced race which is on the verge of travelling out of their solar system. Using an asteroid, the research base is able to travel from close to the sun all the way into the outer reaches of the solar system. This lets them study each planet and moon in close detail, and can also act as a slingshot to send probes into deep space. $\endgroup$
    – Aric
    Commented Aug 20, 2016 at 10:48

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