Payload transmitter is responsible for transmission of payload data . As per the requirement, BPSK modulation is being performed followed by the modulated signal up converted to higher frequencies along with the local Oscillator of 433.9MHz. It consists of transceiver and is capable of receiving the control signal from ground station transmitter on the basis of which it transmits all telemetry information i.e. temperature, current and humidity to ground station employing BPSK modulation at different data rates . In addition it is capable of receiving frequency modulated voice/audio signal from ground station and retransmit at another frequency to the ground station receiver. In order to incorporate the telemetry information in the payload transmitter, different types of sensors are used.