A few improvements have been carried out in the PSLV-C3 compared to PSLV-C2. They include introduction of lightweight fourth stage (PS4) tank for better vehicle performance, ball-lock separation system for the separation of auxiliary satellite whose interface is also compatible with the European Ariane vehicle.

The mission profile for PSLV-C3 has been modified to place the three satellites in their specified orbits. The Indian satellite, TES and the German satellite BIRD are placed in a 568 km Sun-synchronous orbit where as the third satellite, the Belgian PROBA will be raised to an elliptical orbit of 568 x 638 km by firing the RCS thrusters of PS4. Two axial thrusters will be fired for duration of about 500 seconds in order to impart the necessary increment velocity to put PROBA in the required orbit.

A Data Storage Unit (DSU), which stores the telemetry parameters and transmits indelayed mode has been introduced, which takes care of any break in the radio visibility between the vehicle and the ground stations located at Thiruvananthapuram and Mauritius as well as recording of the PROBA separation event. The PROBA separation related parameters are transmitted when the stage passes over the Lucknow ground station of ISRO.