GSAT-4 was the nineteenth geo-stationary satellite of India built by ISRO and fourth in the GSAT series. GSAT-4 was basically an experimental satellite with the following new technologies intended to be tested:
* Electric Propulsion System
* Bus Management Unit
* 1553 Bus for Data Communication
* Miniaturised Dynamically Tuned Gyros
* 36 AH Lithium Ion Battery
* 70 V Bus for Ka band TWTAs
However, GSAT-4 was not placed in orbit as GSLV-D3 could not complete the mission.
