Enlarge / SpaceX launches its 28th supply mission to the International Space Station on Monday, June 5, 2023. (credit: SpaceX) In just the last month, both the European and Chinese space agencies have issued a call for private companies to develop the capability to deliver cargo to space stations in low-Earth orbit. On May 11, the European Space Agency announced a "Commercial Cargo Transportation Initiative" that would see one or more providers develop the capability to deliver 2 metric tons to the International Space Station by 2028 and be capable of safely returning 1 ton to Earth.