From the article

>The scientists who devised the new method, outlined in a paper in the journal Frontiers in Astronomy and Space, did so as part of a thought experiment. They aimed to think up a space habitat idea that wouldn't require massive amounts of materials being launched into space.
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>A Manhattan-sized asteroid space habitat
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>The idea they ultimately came up with was to use materials already free-flying around space in massive quantities in the form of asteroids.