Pratham is a 10 kg student satellite built at IIT Bombay to measure the electron content of the ionosphere. PSLV-C35 launched it in September 2016.
No longer operational, according to the public satellite catalogue.
Pratham was designed to estimate the total electron count (TEC) of the ionosphere over India and over Paris, on a 1 km by 1 km grid. TEC data can be used to improve the accuracy of GPS positions in India.
Students in IIT Bombay's Department of Aerospace Engineering built Pratham, mentored by ISRO scientists and IIT faculty. It is a cube about 26 cm on each side and weighs 10 kg.
PSLV-C35 launched Pratham from Sriharikota in September 2016, alongside SCATSAT-1 and the PES University satellite PISAT. It went into a sun-synchronous polar orbit about 670 km up.
The ground station received Pratham's beacon but not its data downlink. The measurements needed both signals, so the TEC experiment did not succeed. The public satellite catalogue lists Pratham as no longer operational.