The stars call us, as Carl Sagan once said. Given the human drive to explore our world and expand our reach, it’s probably only a matter of time before we start building our homes in the solar system. The Moon and Mars could be acceptable destinations, but nearby asteroids could also become hotbeds, a recent study shows.
The cold, weightless, radiation-filled darkness of space poses a number of challenges to human habitation. We must be protected from cosmic radiation and the solar wind, and microgravity poses significant health risks to the human body. This will require us to live under a layer of regolith or soil on the Moon and Mars. Given the low gravity of these worlds, we might be better off living deep within small asteroids that we can spin around to create healthy artificial weight.
We have long dreamed of building a huge rotating space station to settle there, like the one presented in 2001: A Space Odyssey, but the construction challenges are enormous, not to mention the logistics of transporting such large amounts of steel and other materials into space. A rotating station should be at least hundreds of feet in diameter for artificial gravity to be practical. The bigger the better. The engineers therefore proposed to rotate the asteroids as a kind of ready-to-use station. We would need to dig inside, but it would give us materials we could use.
The metal-rich asteroid 16 Psyche is a good possibility. Mining inside its estimated billions of rare-earth metals would also provide a radiation-protected habitat, as long as the rapidly spinning Psyche doesn’t shatter it. On this point, the concept seems promising. A study of spinning asteroids found that solids up to a few hundred meters in diameter should tolerate a rotation speed fast enough to sustain artificial gravity for up to about half a ge.
There is only one problem. Most asteroids at this scale are not solid. Instead, they’re a loose collection of rock and dust known as rubble heap asteroids. They would fly away long before they reached a usable rotational speed. So in this latest study, the team is looking at a compromise design. Rather than relying on an asteroid’s inherent structure, they propose wrapping it in a material strong enough to hold it together while spinning. The packing layer could be covered with solar panels to generate electricity. And the rubble would provide resources and radiation shielding. Such a design would reduce the amount of material needed to lift through space while resourcing more common near-Earth asteroids.
The study found the idea promising but not yet practical. The required tensile strength of the packaging material would exceed that of current materials. But the design is in the range of future materials like carbon nanofiber. By the time we can build a house on nearby asteroids, we may very well have the advanced materials we need. It’s an interesting idea, and it shows how our options for homes in space aren’t limited to the surfaces of the Moon and Mars.
This article was originally published on Universe today by Brian Koberlein. Read the original article here.