"Space rock superstructures...good science or fantasy?" Topic

A recent discussion with my buddy about this subject brought up some interesting thoughts.

As science fiction fodder we have seen this sort of thing before…the asteroid partially hollowed out, rooms, chambers, tunnels, etc.

But does it make any real science sense to use space rocks for a starting point?

A fair amount of these space rocks are high metal based and it is assumed that at least some portion of the body is hardened by conditions of bouncing around in space.

Issues of weak spots, stress cracks, and other potential problems could be detected.

But would it be worth the effort to detract rather than build up for a structure?

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(mini temp camps) picture picture

"Science sense"? As free shielding from solar and other radiation, certainly.

"Engineering sense" even moreso. It would depend on the solidity and composition of the asteroid in question, of course, but the fewer places you have to build in protection from the void outside, the better.

Some asteroids are quite solid, while others are loose collections of space gravel, with plenty of in-between conditions. Some basic geophysical surveying would tell someone "on the spot" whether or not an asteroid was one piece, and continued monitoring of that sensor net would warn of runaway fractures.

Otherwise, the concerns and benefits are similar to creating sub-surface structures on much larger airless bodies, like the Moon.

Two possible advantages I can see:

Biggest cost for constructing a station might be getting materials into orbit, if you can reduce the amount of materials by using the asteroid thats got to be good.

Also you might be able to use the asteroid as a thermal mass to help you regulate the temperature of your station or its large surface area to disipate heat if thats a problem….

However finding just the right type of asteroid in an appropriate orbit for whatever activity your doing might be a deal breaker.

Rock's rock. Yes, you can use an asteroid as a superstructure, just as you can a cave or a mine. Just think of it as Cheyenne Mountain, in space. Best dang shielded site you could have. Same principle, pretty much.

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As long as you're not building skyscrappers on the surface like in some of those pics you should be just fine. :)

On top of what is stated, what about the potential exploitation of naturally occurring resources. Asteroids with the right mineral composition could provide the base resources for expansion, freeing up internal space for said expansion as they were mined.

They'd also provide good armor (protection) against other space debris hurtling through space, such as meteors and, if in the neighborhood, brushes with other asteroids that surface installations would have serious structural issues with.

Engineering, cost, and ease of construction…not to mention being able to potentially use the excavated material as a raw resource.

Rock isn't always quite what you think.
It may not be airtight for a start so any internal structure would need to be self contained for a start, little things like that may negate any perceived advantages.

It may not be airtight for a start so any internal structure would need to be self contained for a start, little things like that may negate any perceived advantages.

Not that hard to check, actually. Or correct. But it still offers excellent shielding from radiation and micrometeors (and some bigger rocks as well).

Camouflage….

Camouflage??? Not against anyone with IR sensors. That waste heat has to go somewhere, and your asteroid base just isn't going to look like an uninhabited rock. At best you might disguise the nature and extent of an installation, not its presence.

As actual ships, I have my doubts rocks will ever be a better deal than custom-built hulls. They do offer you plenty of waste material for use as reaction mass in an accelerator-based propulsion system, though. I expect we'll eventually nudge ones into some kind of closer-to-Earth orbit for ease of mining, with startup mining efforts begun in the Belt (or wherever we pick up the rock in question) and the tailings fed into mass drivers to push the rock closer to home. Of course if you're doing that every kilo of refined metals slung toward Earth is a push in the wrong direction, so the trip's likely to be a very slow one.

A solid Iron/nickel asteroid is practically ready made as a structure, according to the papers and engineering studies I've seen on it.

In fcat, there is even one stranger idea: Take a solid iron/nickel 'roid, and drill into its centre. Fill the cavern with water and seal it; Then, using a mirror some hundred metres across, reflect light from the sun onto a point on the asteroid, while using thrusters to rotate it about its axis.The water expands, the metallic rock heats up and you now have a larger, rounder and more hollow structure for use. Will it work? Maths and geological experience says probably if done right.

All points I had considered:

find the right big rock
cut it like a diamond if needed
core, bore, hollow
reserve materials for raw processing
then seal

I am thinking that a high pressure system that would push a flexible material throughout the processed surfaces. An elastomeric skin that would have thermoplastic qualities…so any serious heat…impacts, fire, radiation reaction, etc. would cause the material to liquefy flow and then solidify once cooled…this would in theory create a void filling/sealing quality.

If any fissures developed then these layers of skin would ebb hold the damage in place, allowing the repairs to be conducted.

I would imagine there are many issues that would make the process impossible or completely possible that are beyond us at the moment, but at least the idea of recycling an appropriately suitable metal based space object is at least an interesting subject.

Certainly the space rock ship/base is more feasible than some other common science fiction icons…teleportation, warp drive, hundreds of intelligent humanoid aliens, etc..

I am sure there are issues that speak volumes of why not, but I for one would at least consider it potentially good science.

@covert…now there is a properly interesting idea. Well done.

"@covert…now there is a properly interesting idea. Well done."

Been bouncing around SF and space science/engineering for over a decade, actually.

There was talk back in the late 60's about making "hollow balloon" asteroid habitats like Covert was talking about by using nuclear fission for a heat source. Not to be paranoid about radiation, but the solar power version sounds like a better way to make someplace to live in.

Lots of cool ideas out there:

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I'm sure some (or most) of them are a little "out there" though.

Dan
PS. This is a neat, albeit fictional, layout:
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You can also 'throw' them at other space rocks or even planets for nice firework effects…

The plan usually isn't to just leave bare rock walls. The idea is that you're drilling tunnels anyway to mine ore.

If the asteroid is differentiated, then you're trying to move deeper in to get to the metals. But even if it isn't, you want to be working with as much mass between you and cosmic radiation as possible. The tailings from drilling are processed as ore. The tunnel, when you get deep enough, becomes your first main corridor. You line it with something stylish, practical, and air-tight.

Consider the alternative. At first, you'll HAVE to either live on your ship or build on the surface of the asteroid. But that leaves you more vulnerable to micro-meteor impacts and radiation. Going deep is win-win and only costs drilling time and effort-- which you are already expending on a mining mission. This is the case even for an ice asteroid (again, just because you're tunneled into ice doesn't mean you have to use ice for the walls).

Asteroids, even little stoney ones, are PACKED with valuable ore. You'll be there for years, not months. In fact, odds are that you're not out there to export materials, you're mining to supply a new base you're building for other reasons (since even a couple rocks would supply Earth for centuries, a smart company would move a big asteroid into earth orbit, build a base there, and establish a major commercial operation to mine it).

The only three reasons to potentially stay on a ship are if:

a) Your asteroid is a rubble pile and therefore unsafe.

b) Gravity: not every asteroid is stable or shaped right for spinning. You avoid bone degeneration and muscle atrophy if your ship has its lifesystem in a centrifuge, so you'd likely stay there. Though eventually you might BUILD a spin gravity habitat underground.

c) Dust mining: If you're there for a quick hit of minerals from dust mining, you won't be drilling anyway. Then you might just stay aboard ship, get the easy pickings, then leave for the next asteroid.

Oh, and one other thing: available space.

On earth, we measure space in SURFACE: square feet of housing, for example. In space, real estate is measured in VOLUME.

You would be totally flabbergasted by the potential population of even a small asteroid if it's properly hollowed out. I did some calculations once and couldn't believe them myself, even with generous assumptions about the volume of life-support equipment.

Battleworks Studio said – "Not to be paranoid about radiation, but the solar power version sounds like a better way to make someplace to live in."

Not only that, but way cheaper; The sun pours out energy for free beyond the atmosphere on a full rnage of wavelengths, so utilizing them at least within the Earth/Moon system is pretty damn cost-effective.

Asteroids are not flying mountains of solid rock. They are loose piles of dust and rubble.

Asteroids:

Asteroids, also known as minor planets or planetoids, are small rocky and metallic celestial bodies that orbit the Sun.
What are Asteroids Made Of?
Asteroids are considered to be remnants of an early broken planet of the solar system. Asteroids have no fixed shape and are too small to be spherical in shape. They are ellipsoids, dumbbell, or irregularly shaped.

As they have different shapes, they also vary in their size. The first asteroid Ceres, discovered in January 1801 by Italian astronomer Giuseppe Piazzi, is the largest known asteroid and is 940 km in diameter. Some of the smallest asteroids are just 6 meters in diameter. The mass of all the asteroids added together, is believed to lesser than than the mass of the Moon. Only 200,000 asteroids have been discovered so far, but billion more undiscovered asteroids still exit in our solar system.

Asteroid Belt

Most asteroids lie in the asteroid belt between Mars and Jupiter, however there are more belts in the solar system, namely the ones beyond Neptune's orbit. The belt itself has interesting origination theories. Most astronomers believe that the belt is a broken planet, while some say that the belt is primordial material that never coalesced into a planet because of Jupiter's gravitational pull. The asteroid belt lies between the orbits of Mars and Jupiter and contains more than 200 asteroids larger than 100 km in diameter, and more than 750,000 asteroids with diameters larger than 1 km. Most asteroids are found in this belt because of the gravitational interaction between the solar system and the celestial bodies in it.

As opposed to the fiction made popular by various depictions of the asteroid belt, it is not at all dense. The region is so vast that asteroids are hundreds of thousands of kilometers away from their closest neighbor. The asteroids are so small and far away from each other that they appear as faint stars, and except for Ceres, are not bright enough to be seen without some telescopic aid. Only the asteroid Vesta, on rare occasions of an extremely clear dark sky can become visible to the naked eye.

What are Asteroids Made Of?

Asteroids are made of different minerals and substances. This depends on the planet they broke away from in a collision, as well as the chemical reactions they might have experienced while orbiting in the solar system. The asteroids closest to the Sun are mostly carbonaceous and the ones further away are composed of silicate rock. The metallic asteroids are made of 70-80% iron and the remaining is nickel with many other metals such as iridium mixed in. Some are also made of half silicate and half metallic.

The asteroid Ceres is composed of a rocky core covered by an icy mantle, whereas Vesta has a nickel-iron core, basaltic crust and a covering of magnesium iron silicate (olivine mantle).

Asteroids composition has been classified as the following:

C class asteroids: They are found in the Earth's outer belt and are darker and more carbonaceous than the ones found in the S class.

D class asteroids: They are also known as Trojan asteroids of Jupiter and are dark and carbonaceous in composition.

S class asteroids: They are found in the Earth's inner belt, closer to Mars and are composed of mostly stone and iron.

V class asteroids: They are a far-out group of asteroids that follow a path between the orbits of Jupiter and Uranus, and are made of igneous, eruptive materials.

A near-Earth asteroid collided with the Earth about 65 million years ago, which triggered environmental changes, leading to the extinction of the dinosaurs. This asteroid created a huge circular depression called the Chicxulub Basin and is centered in Mexico's Yucatan Peninsula, a major tourist attraction. Though the chances of asteroid collision with the Earth is very rare, they do come very close to our planet due to collisions and gravitational tugs on the highly elliptical Sun's orbit. Most asteroids burn up in the atmosphere and never reach the Earth.

NASA projects, such as the Lincoln Near-Earth Asteroid Research (LINEAR) and the Near Earth Asteroid Tracking (NEAT) main objectives are to detect and intercept asteroids or other celestial bodies coming close to the Earth before they cause untold damage to our planet.

Asteroids are made of rocky and/or iron-nickel material and most are found in an orbit between Mars and Jupiter. Most are pitted with impact craters and dust left from collisions with other objects in the solar system.

The current hypothesis on asteroid composition, introduced about twenty years ago by Don Davis and Clark Chapman and refined since, states that most asteroids larger than one kilometer across are actually composites of smaller pieces that vary in size from over a kilometer to a mere few meters across, matching observations about size and spin rate. It has been discovered that no asteroid larger than 200 meters in diameter rotates more than once every two hours – around ten times per day. If these asteroids are made of rubble then they would fly apart if they rotated any faster. Smaller asteroids that can rotate once every few minutes must be composed of solid rock. No matter what they are made of, asteroids are too faint to be seen with the unaided eye (or without a telescope).

Historically, asteroids have given us clues as to how our solar system was formed. According to a popular theory, the four inner planets were formed when asteroids of different sizes all clumped together and over time became round, forming Mercury, Venus, Earth and Mars. Beyond that, many astronomers hypothesize that all or most of the asteroids making up the contents of the asteroid belt were actually all a part of a planet – probably rocky – that was ripped apart due to the gravitational effects of Jupiter (yes, it's that strong!). In our day-to-day world, asteroids inspire both awe and fear.

Asteroids are made of rock and metal. They are mainly grouped into three categories: Stony, Iron-Nickel, and a mixture of the two. Most asteroids that we know about (92.8%) fall into the first category, and are made of Silicates. 5.7% are Iron-Nickel. The balance form the third type. Despite their relative abundance, stony asteroids that have fallen to Earth are the hardest to find because they look like terrestrial rocks and they weather much faster than the metallic ones.

There are several different types of asteroid, and they tend to be sorted by distance from the Sun, although there are plenty of exceptions. Generally the nearest to the Sun tend to be mostly carbon, much like the two moons of Mars. These are called carbonaceous.

Further out tend to be primarily silicate rock. Beyond these we find the metallic asteroids, made of about 70-80% iron, and the balance mostly nickel, but with many other metals mixed in, including some that are rare on Earth, such as iridium. There are also some that are about half silicate and half metallic.

Asteroids are made of different minerals and substances. Their composition depends on which planet they may have originated from. Many asteroids are the result of larger asteroids hitting planets or each other during the fiery beginnings of the Solar System. The chemical reactions that they have undergone over the millennium also effects their composition. The asteroids that are nearest the Sun are mostly made of carbon while the ones further away are made up of silicate rock. The metallic asteroids are composed of up to 80% iron and 20% a mixture of nickel, iridium, palladium, platinum, gold, and other precious metals. There are those few that are made up of half silicate and half metallic.

What are asteroids made of? Well, that depends on which class they are. There are four major classes of asteroids: C type, D type, S type, and V type. Each has a different composition and position in the universe.

C type are found in the outer areas of the main belt and are darker and more carbonaceous the the S type.

S type are found in the inner area of the main belt, closer to Mars, and are composed of mostly stone and iron.

D type are also known as the Trojan asteroids of Jupiter and are dark and carbonaceous in nature.

V type are a far out group. They hang out between the orbits of Jupiter and Uranus and are made of igneous, eruptive materials.

Now that you know what are asteroids made of, here a couple of interesting facts about them.:

All asteroids are covered in space dust called regolith. This dust is usually a rocky rubble more than dust. It is the result of the constant collisions the asteroids undergo in space. The larger asteroid usually wins n these collisions and ends up covered in the rubble of the loser.

Some asteroids have moons of their own. The spacecraft Galileo first discovered an asteroid with a moon in 1993 when it flew by the asteroid 243 Ida.

Asteroids like to group together in the solar system. There are four main groups of asteroids. There are the main belt, the Kuipers, the Trojans, and the scattered disc. Theoretically there is a fifth group called the Oort cloud, but it is too far out into space to be studied.

I plucked those from various NASA linked sites.

Generally I suspect there are some softer rock/compressed dust but the general consensus is rock/silicates and metal.

There seem to be fewer metal asteroids but those tend to be nearly all metal.

So finding the right asteroid and then applying the right processes could provide a decent platform, IMO, not that my opinion holds any water :)

28mmMan -
You rock.

;)

Lampyridae, yes, but not many.

First predicted by Carl Banks in a Donald Duck cartoon*, rubble pile asteroids were later discovered in reality; However, they are rare ( This link has an article on Mathilde, a suspected and rapidly being confiremd rubble pile ) and solid nickel/irona nd chondrite asteroids seem to be the main, as mentioned by 28mm Man at some length. :) More here – link

*Seriously. Donlad Duck also is credited with Banks as being the first people to consider Methlyene Chloride, an industrial solvent I used to use every day at work, as a sytnthesisable fluid when most chemists thought it as unlikely as controllable Fluorine.

Carl Barks, not Banks. Yes, he was very imaginative and was recommended extracurricular reading in one of the college futurism courses I took decades ago. Then again, he ought to be mandatory reading for any creative writing or graphic arts course – one of the finest comic storytellers in history, and sadly underappreciated today.

I'd think "gravel" asteroids might still be useful. Not only would they be relatively easy to process and refine when looking for resources, the "tailings" from such activity could be fused with heat or bonded like concrete to produce a solid shape for rock-ship construction.

So this has turned into a…solid…conversation. :)

I am still on board that at least in some way the idea of using asteroids as superstructure has value.

Maybe, consider a three stage installation.
(after finding an appropriate asteroid)

1. bore/core deep enough to reach the protective layer, cap this with an inset access port

2. use this tube as a conduit to further core/bore side tubes and insert modular units (living quarters, generators, hydroponics, etc.)

3. as a section reaches a safe yet full capacity create a series of baffled upper locks and seal the environment below

This way if the asteroid in question has issue along the development process then there is time and ability to pull the resources out and start anew. If the asteroid is viable then these packet towns could/would link together creating a network of sub-cities.

@ Covert Walrus,

Most asteroids (in terms of numbers not percentage mass of the Belt) are pretty small, houses up to a hundred metres or so, and are just clumps of boulders and dust. Van Der Waals forces are stronger than gravity at this size. The bigger asteroids seem to be more monolothic as you say.

@28mmman,

Sounds good. You'll probably need inflatables for pressurised living areas in all cases. Dust will be a problem as on the moon and Mars.

Most asteroids (in terms of numbers not percentage mass of the Belt) are pretty small

What's the rule of thumb? "For every object of a given mass, there are X objects of half that mass." And X is a remarkably stable value regardless of base mass.