The Vikram Sarabhai Space Centre, a major space research centre of the Indian Space Research Organisation, successfully test-fired a hybrid motor at the ISRO Propulsion Complex (IPRC), Mahendragiri, Tamil Nadu, on Tuesday, September 20, 2022. The test-fire was supported by the Liquid Propulsion Systems Centre (LPSC), a research and development centre functioning under ISRO. A hybrid motor, unlike solid-solid or liquid-liquid combinations, uses solid fuel and liquid oxidizer. The 30 kilonewton hybrid motor tested by ISRO used Hydroxyl-terminated polybutadiene (HTPB) as the solid fuel, and liquid oxygen as the oxidizer, which are compounds readily reacting with most organic material without any energy input.
ISRO's test of the 30 kilonewton hybrid motor demonstrated ignition and sustained combustion for the intended duration of 15 seconds, the Indian space agency said in a mission update. The performance of the hybrid motor was satisfactory.
Importance Of The Hybrid Motor
The use of liquids in the hybrid motor facilitates throttling, a term used to define the regulation of propellant flow rates by control valves. Therefore, throttling refers to thrust modulation in a liquid-propellant rocket engine.
The control over the flow rate of liquid oxygen enables the restart capability of the motor. Both HTPB and liquid oxygen are green. However, liquid oxygen is safer to handle.
See Here | Early Satellites To Moon Missions: ISRO Milestones Since Independence. In PICS
The advantages of the hybrid motor are that it is a safe propulsion system, ensures green propulsion, and is throttable and restartable.
ISRO said in the mission update that the hybrid motor is "scalable and stackable", and potentially paves the way for a new propulsion system for future launch vehicles.