As part of the Outer Space Treaty, putting nuclear weapons in orbit is indeed forbidden, and both America and China have signed up. But it's worrying that several nations now seem to be testing space-based weapons and edging closer to violating the treaty. The risk is the treaty gets ignored or discarded, and we end up with a really terrifying arms race in orbit.

Once I studied physics and distant galaxies. Now I fly satellites instead, and spend my time thinking and writing about trends in space and technology.