The electromagnetic railgun is not an object of science fiction after all since the United States Navy fires a projectile using the technology. While the idea of using the electromagnetic railgun in warfare is tempting, it appears that the technology was proposed for scientific purposes instead. While it is not feasible to catapult astronauts with 6 times faster than sound, for now, the technology could be deployed for tossing objects from the space to earth, vice versa.
According to Space, the electromagnetic railgun peaked at Mach 6, which means six times the speed of sound. If astronauts can station at the moon and mine resources, the said speed is just a fraction "slower" than the escape velocity. Theoretically, nonmagnetic payloads from the moon could be tossed to earth.
It is exciting to consider the deployment of the electromagnetic railgun in the moon's surface. Astronauts can mine ore chunks from the cosmic body. Thereafter, the electromagnetic railgun can toss the material into space. Next, these raw materials can be utilized to build space colonies. This idea was first proposed in 1974 by Princeton University professor Gerard O'Neill. When he died in 1992, the idea petered out until recently.
However, the electromagnetic railgun is still far from being capable of launching or propelling objects of larger mass like moon ores. The experiment only worked with small projectiles for now. Anything that is larger will require a complicated thermal management and a huge amount of electricity to reach hypervelocity. Wired explained that electromagnetic railgun uses electricity instead of the traditional chemical propellants.
Another issue is the size of the electromagnetic railgun needed to successfully launch a space vehicle. Based on current prototypes, a 160-meter long mass driver is needed. This means a lot of resources and a significant amount of power. Only by then will the electromagnetic railgun breach the 5,300 miles per hour requirement for the escape velocity at the moon.