ISRO's Polar Satellite Launch Vehicle, PSLV-C27, successfully launched the 1425 kg IRNSS-1D, the fourth satellite in the Indian Regional Navigation Satellite System (IRNSS) on March 28, 2015.

This is the twenty eighth consecutively successful mission of the PSLV. The satellite will help augmenting the satellite based navigation system of India which is currently under development. The navigational system so developed will be a regional one targeted towards South Asia. The satellite will provide navigation, tracking and mapping services.