ISRO has successfully completed a series of Crew Module (CM)-Service Module (SM) Separation Tests for the Gaganyaan missions. Gaganyaan Orbital Module comprises of Crew Module (CM) and Service Module (SM) which are connected using a separation system. Electrical & fluid servicing between CM & SM is ensured through umbilical connections. These modules are integrated prior to the launch and function as a single integrated module from launch till the completion of the on-orbit phase of the mission. Prior to commencing re-entry into the earth’s atmosphere, the CM is separated from the SM. Separation of CM from SM involves multiple precisely sequenced separation events involving pyrotechnic devices and jettisoning systems. In order to validate the overall design adequacy of the separation system, a test setup was realized at Vikram Sarabhai Space Centre, Thiruvananthapuram, for simulating the overall CM-SM assembly with extensive instrumentation. The tests simulated the scenario of CM-SM separation involving the severing of several umbilical connections between CM & SM. Besides validating the design adequacy of the overall CM-SM separation systems, these tests have also demonstrated robustness and shock-survivability of various critical subsystems in the CM. These include various Avionics systems, Inertial Navigation Systems, Thermal Protection System in the Aft & Conical Heat Shield, Crew Module Deployable Umbilical Shield as well as pyrotechnic devices of Crew Module Uprighting System and Thermal & Humidity Control System. This provides necessary confidence in the functioning of the implemented CM-SM separation system for the upcoming 1st uncrewed Gaganyaan Mission (G1) mission which is targeted for launch in 2026. #ISRO #HLVM #GAGANYAAN