The Onboard computer (OBC) is the brain to a satellite. The primary role of the OBC is the control all subsystems of the satellite. It collects information from different subsystems of the satellite, analyzes the information, and takes necessary and appropriate decisions as and when required.

The onboard computer performs several different tasks. The most important are :

  1. Receive and respond to commands from the ground station as well as handle the general housekeeping of the satellite.
  2. Collect the telemetry data, format and encode the data for transmitting to the ground station.
  3. Attitude determination and control by monitoring earth’s magnetic field using control algorithms.
  4. Monitors temperature of all subsystems and maintains the satellite in specified temperature range using heaters.
  5. Store payload and telemetry data during non-visible period for transmission during visibility.

Other SubSystems


Battery tied bus being the simplest power system configurations, has been selected for its minimal complexity.


PISAT is configured as a three axis stabilized satellite to meet the pointing and stability requirements of the Imaging payload.

RF Systems >

PISAT is configured to have TT&C links in the standard TT&C S-band. The operating frequencies are selected to avoid interference to and from the assigned and currently used frequencies of satellites as well as the launch vehicle – PSLV.

Payload >

The payload selected for imaging the earth is a COTS “NanoCam C1U” from Gomspace Inc. NanoCam is a flexible and modular system to rapidly implement tailored imaging systems.