Gamma-ray bursts (GRBs) are the most luminous electromagnetic events occurring in the universe since the Big Bang. They are flashes of gamma rays emanating from seemingly ranom places in deep space at random times. The duration of a gamma-ray burst is typically a few seconds, but can range from a few milliseconds to minutes, and the initial burst is usually followed by a longer-lived "afterglow" emitting at longer wavelengths (X-ray, ultraviolet, optical, infrared, and radio). Gamma-ray bursts are detected by orbiting satellites about two to three times per week, but the number of GRBs that could be observed from Earth is about three times as many and it is currently limited by the efficiency of the instruments.