Star Wars research: technician working on test equipment at the end of the Advanced Test Acclerator (ATA) at Lawrence Livermore Laboratory. The ATA is designed to accelerate a short, high intensity pulse of electrons to an energy of 50 million electron volts (MeV). The frequency of firing is limited to a 10 pulse burst every 2 seconds. Space-based accelerators that produce high-energy particle beams capable of disabling distant objects such as ballistic missiles are one class of potential weapon under investigation in America's Strategic Defense Initiative (SDI) - the Star Wars program.