A Mumbai-based start-up, Techno Defence Pvt Ltd, has successfully developed an indigenous Joule-Thomson (JT) Cooler for missile seekers, breaking a long-standing Western monopoly and opening up a high-value defence export market, Business Line reported.

The innovation, achieved with DRDO support, is now attracting international interest but remains subject to strict Missile Technology Control Regime (MTCR) restrictions.

The breakthrough began with a chance meeting between IIT-Bombay alumnus Dr Pravin Salinkar and a DRDO lab director around 2017–2018. Salinkar, aged 75, accepted the challenge of developing a critical defence technology.

Alongside fellow IIT-Mumbai alumnus Sudarshan Saraf, he co-founded Techno Defence Pvt Ltd, assembling a small team of engineers and technicians, mostly women, to tackle the project.

By 2020, the team secured funding under DRDO’s Technology Development Fund (TDF) scheme to design and build the JT Cooler. This miniature, lightweight, vibration-free device rapidly chills infrared sensors and focal plane arrays in missiles to cryogenic temperatures of approximately –196 °C.

Such cooling is essential because infrared seekers generate their own thermal energy at ambient temperatures, producing background noise known as dark current. This noise can overwhelm weak infrared signals from distant targets, causing the missile to lose track. The JT Cooler suppresses this internal noise, enabling precise target detection and tracking.

The JT Cooler is a strategic technology controlled under the MTCR and previously possessed only by countries such as the United States, France, and Israel. It is not required for missiles that rely on satellite navigation systems, but for infrared-guided seekers it is indispensable.

Techno Defence’s design differs from foreign models, relying on specialised production techniques and equipment developed in collaboration with small-scale and cottage industries. The assembly process demands skilled work under microscopes, pure materials, and clean environments, all subject to stringent quality controls to meet defence-grade reliability standards.

By 2023–24, the project was completed and handed over to DRDO for trials, which proved successful. The indigenous JT Cooler has now positioned India as a credible player in a niche but strategically vital defence technology domain.

The innovation has already attracted interest from foreign buyers, though exports require special permits due to MTCR restrictions. This marks a significant step in India’s defence self-reliance program, reducing dependence on imports and strengthening the country’s technological sovereignty.

Techno Defence operates as a joint venture with Technocraft Industries (India) Limited, giving the project a strong industrial base.

The company has also collaborated with DRDO’s Solid State Physics Laboratory and Research Centre Imarat, ensuring scientific depth and operational credibility. The JT Cooler joins a growing list of indigenous defence technologies that India is developing to meet both domestic needs and international demand.

The lean manufacturing success story highlights how a small team, leveraging local industries and innovative design, cracked one of the most complex engineering challenges in missile technology.

It demonstrates India’s ability to compete in high-value defence markets, while also showcasing the role of DRDO’s funding programs in nurturing private-sector innovation.

Agencies