General Atomics has developed an electromagnetic catapult launch system for launching fighter planes from aircraft carriers, called the EMALS. The first EMALS system is intended for installation on the USS Gerald R. Ford being launched later this year.
The EMALS is a linear electric motor that will replace the steam catapult systems.
Developed in a linear induction motor configuration, the launch motor is a compact, modular, integrated flight-deck structure that converts electrical current into the electromagnetic forces to accelerate the aircraft along the launch stroke… A simple moving shuttle will interface with the aircraft in the same manner as the existing catapults. After the aircraft launches, the electric current in the motor will reverse to brake the shuttle to a complete halt without the use of a water brake…
The EMALS system is a multimegawatt electric power system involving generators, energy storage, power conversion, a 100,000 hp electric motor, and an advanced technology closed loop control system with diagnostic health monitoring.
The details of the system are not available, but it probably requires large capacitive storage banks capable of supplying extremely high currents (probably 1000s of Amperes) for the 2 to 3 second operation time. The charging will probably be slower, probably taking several minutes. But the system should be able to handle launching fighters rapidly in a combat operation. Aircraft carriers are fortunately powered by nuclear reactors that can handle such large power loads.
This system is similar in operation to Magnetic Levitation (Maglev) trains, which General Atomics also develops. They are also working on a maglev system that reach Mach 10. That sounds remarkably similar to the US Navy’s Railgun system which performed a test launching a projectile to Mach 7.5. The single shot test expended a huge amount of energy, rated at 33 MJ.
Here is a link to a video and news report of the first ground test of the launch system launching an F/A-18 fighter plane at a naval station in Lakehurst, NJ, dated December 22, 2010.