On July 30, 2025, the GSLV-F16 rocket soared from the Satish Dhawan Space Centre in Sriharikota, marking a triumphant moment for researchers at SonaSPEED laboratories in Salem and Bengaluru. Their Simplex Permanent Magnet Stepper Motors powered the National Aeronautics and Space Administration (NASA)-Indian Space and Research Organisation (ISRO) Synthetic Aperture Radar (NISAR) mission, a groundbreaking Earth observation initiative.

Developed at Sona College of Technology’s Sona Special Power Electronics & Electric Drives (SonaSPEED) division in Salem, and manufactured in Bengaluru, the Simplex Permanent Magnet Stepper Motors are integral to the GSLV-F16’s actuator assembly.

These motors precisely regulate the fuel-mixture ratio of liquid hydrogen and oxygen, ensuring stable combustion and reliable performance of the cryogenic engine during the rocket’s final ascent phase.

Mission-critical technology

The sophisticated, yet, simple design of the Simplex motors ensures accurate position control, which is vital for maintaining trajectory fidelity, and stable combustion during the high-stress launch sequence.

This precision was crucial for the successful deployment of the NISAR payload, which offers all-weather, day-and-night imaging for global climate and disaster monitoring.

SonaSPEED has been a trusted ISRO partner for nearly two decades, supplying space-grade components like Permanent Magnet Stepper Motors, BLDC motors, and reaction wheels for missions such as Chandrayaan-2, Chandrayaan-3, and the RLV landing test. Notably, these motors played a pivotal role in the actuator assembly for Chandrayaan-3, enabling India’s historic lunar south pole landing in August 2023.

SonaSPEED is one of 36 R&D centers at Sona College of Technology, an autonomous institution under Anna University.