Colonizing Space, Issue #1: Spin Gravity Is Essential and Non-Negotiable

The space station in 2001: A Space Odyssey. This seemed so plausible in the 1960’s, but now we know better: it’s simply too small. If it spun quickly enough to provide spin gravity equivalent to Earth’s normal gravity, steel construction like that probably wouldn’t be strong enough — the station might well fly apart.

Consider the space station. Not just any ol’ spaceborne habitat like the International Space Station or China’s Tiangong space station, but one that really inspires dreams of humanity reaching for the stars — like one above from 2001: A Space Odyssey. What’s the most important feature of that iconic space station? The fact that (at least in the movie) it rotates quickly enough for humans on its outer wheel to experience earthlike gravity a.k.a. ‘spin gravity’. You see, it turns out that even with a strict daily regimen of strenuous exercise, long-term exposure to microgravity is truly bad for one’s health, and the prospects for human reproduction in microgravity are worse than dismal.

But must we have the full earth-normal 9.8m/s² of gravity? There are several private companies planning to build space stations for either space tourism or research, two of which — Airbus and Orbital Assembly Corporation (OAC)— are planning the construction of space stations with spin gravity. OAC’s plans are for two spaceborne “business parks” for work and leisure for up to 400 residents with spin gravity at .57 of Earth normal. But there’s a glaringly-obvious problem with their proposed designs that will be discussed in the next article in this series.