Development of INLS 3U Uni-Pod Nano Satellite (CubeSat) Dispenser System for 3U Class Satellites

With the present state of the art technology, size and mass of the satellites have come down. This necessitated the need for a low shock separation system that does not have mass attached to the separated satellite. Development of Nano satellites with mass of the order of 1 to 24 kg has become popular among scientific/ academic institutions for carrying out scientific experiments. INLS 3U Uni-Pod System (Nano satellite dispenser system) is a satellite dispensing system designed by ISRO for accommodating four 3U class Nano satellites in a single structure where each satellite is deployed independently by separate actuation commands. INLS stands for ISRO's Nano satellite Launch System. The INLS 3U Uni-Pod separation system successfully flown in ISRO’s Launch Vehicle mission for deployment of three satellites from abroad. CubeSat separation system consists of a structure housing the satellite, Holding and release mechanism (HDRM), rattling arresting mechanism, satellite ejection mechanism and movement arresting/ locking mechanism. The system was designed and developed for accommodating four satellites with a maximum mass of 6.0 kg, meeting the CubeSat Design Specification (CDS). Wire fusing system is used as HDRM. Helical compression spring with pusher plate is used for ejecting the satellite. Mechanism with double torsion spring is used for rattling arresting. The system was tested in ground conditions and in thermo-vacuum environment (-15°C +60°C) nearly 40 times and found meeting the design specifications. The actuation time, separation time, electrical specifications, separation velocity and rates are designed at par with the internationally available commercial systems. The satellite ejection time is within one second from command. Confirmation of satellite separation is through micro switches and reed switches. The system can be mounted in two configurations, viz rail mounting and back mounting.