US firm Vast is developing spinning space stations with artificial gravity to keep astronauts healthy on deep-space missions and push the search for alien life.

The imaginary constructions of science fiction fill us with awe at their alien vastness. Which have you explored, and what was the most overwhelming?

Private companies are racing to redefine what a space station looks like, and one of the boldest ideas on the table is a platform that can be launched in a single mission instead of assembled piece by ...