With SpaceX completing the biggest public offering in history, Elon Musk’s reusable chemical rockets seem to be the only game in town for getting to space.But halfway around the globe, a little-known Chinese town tucked against the Tibetan Plateau could change all that.In late March, the government of the city of Ziyang said a research facility successfully tested a high-temperature superconducting navigation system, which they said was a breakthrough in electromagnetic rocket launch...