Indian Data Relay Satellite System


Indian Data Relay Satellite System or IDRSS is a planned Indian satellite constellation, similar to Russian Luch satellites, American Tracking and Data Relay Satellite System and European Data Relay System. Planned to initially comprise two satellites in GEO, it is to facilitate relay of information between various Indian spacecrafts, in-flight launch vehicle monitoring and assist Indian Human Spaceflight Programme.

Objectives

A Data Relay Satellite System facilitates continuous real-time communication between Low Earth orbit bound spacecrafts to the ground station as well as inter-satellite communication. Such a satellite in geostationary orbit can track a low altitude spacecraft up to almost half of its orbit.
India operates one of world's largest remote sensing satellites systems. Visibility of these satellites is not more than 10-15 minutes in a day and sometimes even lower. The IDRSS satellites, one opposite to each half of earth in GEO, can see about 80 per cent of the area where Indian remote sensing satellites are orbiting, hence enhancing visibility range and data transfer rates of satellites. IDRSS can also monitor a launch vehicle from the time it lifts off from the launch pad. Satellites will hereby also reduce dependency on ground stations. Implementation of the system will be essential for tracking Gaganyaan, India's future crewed spacecraft.
IDRSS satellites would be based on 2,000 kg class, I-2K bus with wrapped rib type unfurlable antenna of 6 metre diametre and will carry optical communication payload for increased data security and high transfer rates.

Satellites

Launch

IDRSS was approved by Government of India and had funds allocated in budget of 2019-20. DRSS-1 would be first spacecraft of IDRSS constellation and its launch is currently scheduled for 2020.