A team of Finnish researchers proposed building a settlement of thousands of cylindrical spacecraft that would float around the dwarf planet Ceres - found in the asteroid belt.
An artist impression of the O Neill Cylinder that could house thousands of humans in space.(NASA)
Ceres - at 960km wide is the largest object in the asteroid belt between Mars and Jupiter - and has abundant nitrogen - critical for supporting human life.
Under the plan, each spacecraft- all linked together inside a disk-shaped frame - could hold up to 50,000 people. To create Earth-like gravity conditions, they would have to orbit Ceres in only 66 seconds.