Habitat inside an asteroid
Asteroid mining is a very popular topic these days. After all, asteroids contain all sorts of things: precious minerals to bring home, metals to build space rockets with, water for the astronauts to drink (or turn into fuel)…there is a lot out there we would like to get our hands on.
But the mined hollowed out asteroid might be even more useful to us! How? We can turn them into space stations! And not just any space stations, but fast spinning stations with artificial gravity inside.
Gravity is good, no gravity is bad
Gravity is very important for humans. Without feeling our ups and downs we tend to lose bone mass, develop muscle atrophy and all kinds of unpleasant things. The minimal pull we need to stay upright is thought to be about 38% of the pull we feel when standing on the surface of the Earth. Or about as much as you will feel if you ever visit Mars.
Luckily, we can simulate gravity by simply spinning a spaceship or a space station. The centrifugal acceleration created by the rotation will feel pretty much like gravitational force to us with “up” directed radially towards the axis of rotation and “down” in the opposite way.
In practice, though, to create the desirable Earth-like acceleration of 1g we will have to spin out spaceship pretty fast. Alternatively, we can build a VERY large space station and spin it at a slower rate, say once every minute. That doesn’t sound too bad!
But do we really need the full force of 1g? Remember, the artificial gravity of about 0.38g should keep us healthy and happy!
Space station of the future?
Now let’s combine the two problems: creating artificial gravity and building a space station inside an asteroid! That sounds like an interesting idea, right? It is easy to see the benefits of such a construction. We will be able to use the very materials we mine to build our habitat. And later the shell of the asteroid will be protecting the inhabitants from the harsh space radiation. Plus the artificial gravity will allow the future space travelers to stay there for a long time without suffering the negative consequences of living in micro gravity.
But how realistic this project would be?
We are not even talking about the enormous costs of such an enterprise or about the need for the complicated technology that we don’t have at the moment. We are just curious whether it would be possible in principle to dig the material out of the space rock, build something inside it and set it spinning. Wouldn’t an asteroid with a cavity simply become too fragile and fall apart?
The group of astrophysicists from the University of Vienna investigated the problem of feasibility of such a design in the paper “Stability of a rotating asteroid housing a space station” that appeared on Arxiv this week.
The scientists tried to answer the question whether a real size (there are plans to mine relatively small asteroids up to half kilometer across) hollow asteroids could withstand the fast rotation. And their answer is …YES they can! Though of course we will have to choose the right size asteroid, make sure it is solid inside and dig a certain size and shape cavity in its center. Also, we will be aiming to simulate the minimal 0.38g, not the comfortable 1g we experience on Earth.
Of course, the question remain how we are going to spin our asteroid. The authors suggest that the spacecraft’s taking off and landings can set the space rock spinning. Do you have any other ideas?
So what is the Space Station of the Future going to look like? We cannot wait to see!