Answer:
mass of the earth.
Step-by-step explanation:
During the revolution of a satellite around a central mass of heavenly body:
![\rm Centripetal\ force\ on\ satellite = Gravitational\ force\ on\ the\ satellite\ due\ to\ the\ central\ heavenly\ mass\]()


where:
G = gravitational constant
R = radius of the orbit
mass of satellite and mass of central heavenly body (here we've the Earth)
v = orbital speed of the satellite
