PSLV-C37 also carried two ISRO Nano Satellites – INS-1A and INS-1B. ISRO Nano Satellite (INS) is a versatile and modular Nano satellite bus system envisioned for future science and experimental payloads. The INS system is developed as a co-passenger satellite to accompany bigger satellites on PSLV.

The primary objectives of INS system are to:

• Design and develop a low cost modular Nano satellite in the weight range of 10 kg capable of carrying payloads up to a weight of 5 kg
• Provide an opportunity for ISRO technology demonstration payloads
• Provide a standard bus for launch on demand services
• Provide an opportunity to carry innovative payloads for Universities / R&D laboratories

Source:ISRO