ISRO successfully tests Gaganyaan Low Altitude Escape Motor

11 August, 2022 | Pravina Srivastava

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The test-firing of the Crew Escape System's Low Altitude Escape Motor (LEM) from Sriharikota, Andhra Pradesh, was successfully completed by ISRO

The test-firing of the Crew Escape System’s Low Altitude Escape Motor (LEM) from Sriharikota, Andhra Pradesh, was successfully completed by Indian Space Research Organization (ISRO), according to the officials on Wednesday. This marks another significant milestone in the Gaganyaan project.

ISRO statement read”In the event of an emergency, the Gaganyaan mission’s Crew module is removed by the Crew Escape System (CES), which also saves the astronauts. If a mission is aborted during the opening stages of flight, the LEM gives the CES the necessary propulsion to remove the Crew Module from the launch vehicle.”

LEM is a remarkable special-purpose solid rocket engine that burns for 5.98 seconds (nominal) while producing a maximum sea level thrust of 842 kN (nominal).

In contrast to traditional rocket engines, the LEM’s nozzle end is situated at the front of the launch vehicle to prevent exhaust plumes from impinging on the crew module. A reverse flow multiple nozzle must be used in this solid rocket motor as a result. The reverse flow nozzle alludes to a change in the direction of exhaust gas flow within the nozzle itself.

The space research organisation also listed the main goals of the static test, which included validating the performance of the motor subsystem and confirming the design margins, evaluating the thermal performance of the nozzle liners, particularly to confirm the erosion/ablative characteristics, and evaluating the motor ballistic parameters.

However, the other main reasons included the verification of the integrity of all interfaces, evaluation of the head-end mounted safe arm (HMSA) based ignition system performance, evaluation of the side thrust caused by misalignment, variation in flow, and other functional parameters, including flow reversal.