ISRO test fires hybrid motor to power future rockets

Indian Space Research Organisation (ISRO) successfully tested a hybrid motor that would power its future rockets.

The test was done at ISRO Propulsion Complex (IPRC) at Mahendragiri in Tamil Nadu supported by Liquid Propulsion Systems Centre (LPSC) on Tuesday.

The motor used Hydroxyl-terminated polybutadiene (HTPB) as fuel and liquid oxygen (LOX) as the oxidiser. Unlike solid-solid or liquid-liquid combinations, a hybrid motor uses solid fuel and liquid oxidiser.

According to ISRO, the test of a flight equivalent 30 kN hybrid motor demonstrated ignition and sustained combustion for the intended duration of 15 seconds. The motor performance was satisfactory.

The use of liquids facilitates throttling and the control over the flow rate of LOX enables the re-start capability.

While both HTPB and LOX are green, LOX is safer to handle.

The hybrid motor is scalable and stackable, potentially paving the way for a new propulsion system for the forthcoming launch vehicles.