BeiDou-1 is an experimental regional navigation system, which consists of four satellites (three working satellites and one backup satellite). The satellites themselves were based on the Chinese DFH-3 geostationary communications satellite and had a launch weight of 1,000 kilograms (2,200 pounds) each.
బీడూ-1 వ్యవస్థలో ఎన్ని ఉపగ్రహాలను బ్యాకప్ కోసం ఉపయోగిస్తారు?
one