IRNSS-1B is the second dedicated navigation satellite of India. It is one of the seven satellites constituting the IRNSS space segment. Its predecessor, IRNSS-1A, was launched by PSLV-C22 in July 2013. IRNSS-1B has a lift-off mass of 1432 kg. The configuration of IRNSS-1B is similar to that of IRNSS-1A. The satellite has been realised in less than seven months after the launch of its predecessor.
Payloads - IRNSS -1B carries two types of payloads - navigation payload and ranging payload.The navigation payload of IRNSS-1B will transmit navigation service signals to the users. This payload will be operating in L5 band (1176.45 MHz) and S band (2492.028 MHz). A highly accurate Rubidium atomic clock is part of the navigation payload of the satellite. The ranging payload of IRNSS-1B consists of a C-band transponder which facilitates accurate determination of the range of the satellite. IRNSS-1B also carries Corner Cube Retro Reflectors for laser ranging.