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.
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 .
How many satellites in the BeiDou-1 system is used for back up?
How many satellites in the BeiDou-1 system is used for back up ?
one
one