We will need ever-larger and more powerful rockets as humanity's ambitions expand beyond low Earth orbit, but building these launch vehicles is no simple feat. SpaceX has blown up its share of rockets as it works toward completing Starship, and NASA's timeline for the Space Launch System keeps slipping. China is exploring a different path to the cosmos, one that was abandoned by NASA years ago. Engineers in the country are building a giant electromagnetic railgun that could one day blast astronauts into orbit with next to no fuel.
Reaching orbit doesn't just mean going up—you also have to reach high speeds. Earth's escape velocity is about 24,000 mph (11.2 kilometers per second), but a vehicle doesn't have to reach that speed. As rockets depart Earth, they travel upward while accelerating. At a certain altitude, the pull of gravity is lessened, and the rocket's continued thrust nudges it into a stable orbit. There's no rule saying you have to use a rocket engine to begin that journey, though.
According to a report in the South China Morning Post, the state-owned China Aerospace Science and Industry Corporation (CASIC) has built a 2-kilometer low-vacuum railgun track in Shanxi province. The prototype can accelerate a payload to Mach 1.6 and possibly as high as Mach 5. Many of the glitches that lead to launch failures take place near the beginning of a flight when the engines are operating at maximum thrust. So, a railgun could be a much more reliable way to send a spacecraft on its way.
Even at its highest speed, the proposed railgun isn't powerful enough to send a spacecraft into orbit. After leaving the railgun track behind, a vehicle would have to ignite its rocket engines to continue accelerating upward to reach escape velocity. However, it will take much less fuel and thrust to reach orbit with the added oomph of the railgun.
In the 1990s, NASA experimented with a 50-foot railgun to launch spacecraft, but limited funding and a raft of technical issues prompted the agency to abandon the project. More recent experiments with military railguns haven't gone much better. The CASIC team has found its railgun needs to release the spaceplane at incredible speeds to completely replace a first-stage booster—NASA allegedly underestimated this speed. There are also issues with "colliding shockwaves" when the vehicle breaks the sound barrier so close to the ground. Nevertheless, the company is hopeful it can work out the kinks.
The next step is to extend the railgun track by about five times. That will allow the payload to reach much higher speeds, and a gentler acceleration curve could make it safe for crewed missions.
