Another key U.S. project is the “Phantom Express” XS-1 spaceplane, which is being developed by Boeing and funded by DARPA. It’s a dual-stage-to-orbit (DSTO) vehicle. Stage one: a hypersonic plane powered by liquid fueled rockets. Once the XS-1 is in near space (18- to 62-mile altitude), we reach stage two, when an expendable rocket attached to the plane’s back will detach and fly into orbit to deploy its 1.5-ton payload. The carrier rocket plane then will be able to return to a runway, where it will be prepped for another launch within 24 hours. The plan is that it can undertake at least 10 launches in 10 days, providing the U.S. space system more resilience to replace satellites in the event of a conflict.
China, however, is developing some major competition in this same hypersonic race. There are two separate projects. For one, CASIC debuted the Teng Yun spacecraft design during the Global Space Exploration 2017 (GLEX 2017) conference in Beijing. The DSTO Teng Yun would have a combined weight of 100-150 tons. The first stage is a Mach 6 hypersonic ‘carrier’ aircraft, with TRCC engines that can fly to altitudes of 18 to 25 miles. Unlike the XS-1, the Teng Yun’s second stage is a reusable, 10-15-ton rocket-powered spaceplane capable of carrying either 2 tons of cargo or 5 passengers.