A Chinese aerospace start-up plans to launch a rocket using carbon dioxide, the same compound that gives Coca-Cola its fizz and bite. Hunan-based commercial space firm Zhiyu Aerospace Technology announced on Monday that it was collaborating with another local tech company to apply “supercritical carbon dioxide cold-launch” technology to small launch vehicle systems. Z-Trak Space, as the company is also known, said the cutting-edge method could “truly achieve low-cost, high-frequency,...