When former ISRO chief Dr S Somanath led India to a historic soft landing near the lunar South Pole with Chandrayaan-3, it was hailed as a defining moment in the country's space exploration journey. But in a quiet lab in Chandigarh, another milestone was taking shape - one that may prove even more transformative in the long run. It's called Vikram-32, India's first fully indigenous space-qualified chip, and it could be the cornerstone of a self-reliant semiconductor ecosystem.
"Chandrayaan-3 was the epitome of our interplanetary mission capabilities. But Vikram-32 is the epitome of what we have achieved in silicon-based devices. I think a greater journey is waiting for us," Dr Somanath said.
"Each one is a different achievement," he said, referring to Chandrayaan-3 and Vikram-32 chip.
A Chip Born of Necessity
India's rockets are becoming more complex. Missions like Gaganyaan, Reusable Launch Vehicles (RLV), and future interplanetary probes demand faster computation, more on-board memory, and real-time decision-making. The older Vikram-16 chip, though reliable, was reaching its limits.
"In rockets, everything happens very fast," explained Dr Somanath. "We have something called a minor cycle of operations-typically 20 milliseconds. In that time, the entire on board computation must be completed and posted to actuators or sensors. Vikram-16 was consuming almost 17-18 milliseconds. We were reaching the boundary."
The solution? A new chip with higher clock speeds, greater precision, and more memory. Thus began the development of Vikram-32, designed and fabricated at SCL (Semiconductor Laboratory), Chandigarh, using a 180nm node.
"The Vikram-32 chip was developed entirely in India," said Dr Somanath. "From the architecture to the compiler, the instruction set to the packaging-every single element is our own."
The POEM Test: Proof in Orbit
Before deploying Vikram-32 in a critical rocket system, ISRO needed to test it in space. The opportunity came with POEM-an on-board experiment that takes control of the PSLV's upper stage after satellite injection.
"After PSLV completed its satellite injection, control of the upper stage transferred from Vikram-16 to Vikram-32," said Dr Somanath. "It managed attitude stabilization, payload operations, data transfers, and communication for 30 days in orbit. That's far beyond the typical 15-20 minutes of a launch mission."
The chip not only survived but thrived. It was rebooted, reinitialized, and operated flawlessly, demonstrating its reliability and space qualification.
"The result was extremely good," said Dr Somanath. "It gave us new flexibility-like what we did in Chandrayaan-3."
A Visionary Technologist
While Dr Somanath is widely celebrated for his leadership in Chandrayaan-3 and Launch Vehicle Mark-3 missions, his role in nurturing India's semiconductor capabilities is equally visionary. He credits the success of Vikram 32 to a small, dedicated team at Vikram Sarabhai Space Centre (VSSC), especially S. Mukaiya, who developed the compiler and continued contributing post-retirement.
"I must put the credit to individuals like S. Mukaiya and the small team who designed Vikram-32," said Dr Somanath. "They translated the design into silicon using the technology available at SCL. It was a proud moment when the Prime Minister unveiled the chip at Semicon India 2025."
The chip uses Von Neumann architecture (a foundational computer design where the same memory unit stores both program instructions and data, allowing for flexibility and general-purpose computing), supports Ada-based compilers (a computer programming language) for aerospace-grade reliability, and includes interfaces for peripheral communication. A graphical front-end allows developers to compile and visualise on board software in real time.
"We wanted more precision in computation," said Dr Somanath. "Floating-point operations, reduced truncation errors, and better thermal stability - all of this was built into Vikram-32."
Kalpana-32: A Parallel Path
Alongside Vikram-32, ISRO also developed Kalpana-32, a chip based on RISC architecture or Reduced Instruction Set Computer architecture, which uses a small, simple, and highly optimised set of instructions, enabling faster execution and pipelining, which are key to achieving high performance and efficiency in microprocessors.
Kalpana-32 was not fully indigenous - the wafer was sourced externally - the design and packaging were done in India. Kalpana-32 offers pipelined computation and is being tested for future applications.
"Kalpana-32 is a different architecture," said Dr Somanath. "It's not fully Atmanirbhar, but it's part of our broader effort to build capability. Vikram 32, however, is 100% ours."
Chips Are the New Oil
India's semiconductor mission is not just about space-it's about sovereignty. As global supply chains tighten and chip shortages impact everything from smartphones to satellites, having an indigenous capability is critical.
"Doing some of this really reflects that with whatever semiconductor ecosystem we had-SCL and a few labs-we were able to build quite a lot of devices," said Dr Somanath. "Vikram 32 is the highest of what we did till now. The power of the foundry and the knowledge of semiconductor science were fully utilised."
The chip's success has already sparked upgrades at SCL and the Ministry of Electronics and Information Technology (MeitY), with plans to move to more compact nodes in the future. Vikram-32 may be just the beginning.
"If we have access to a compact node, we can make it more powerful and compact," said Dr Somanath. "But if we want true indigenous capability, we must build it ourselves."
Gaganyaan and Beyond
Will Vikram-32 be used in Gaganyaan, India's first human spaceflight mission?
"That decision is to be taken by the appropriate authorities," said Dr Somanath. "But I believe we can definitely use it.
The chip's performance in February 2025's POEM experiment or the PS4-Orbital Experiment Module and its robust design make it a strong candidate. Its ability to handle complex sensor fusion, on board decision-making, and real-time computation aligns perfectly with the demands of crewed missions.
Legacy of a Leader
When asked how he would like to be remembered-Chandrayaan-3, GSLV, or Vikram-32- Dr Somanath's response was characteristically humble.
"I do not want to be remembered for any of this," he said. "These are accomplishments of our organisation. Vikram-32 is the accomplishment of chip designers in India. I'm sure greater things are going to happen in missions, rockets, and semiconductor development."
But history may remember him differently. As the man who not only landed India near the moon's South Pole but also helped launch its semiconductor revolution, Dr. S. Somanath stands as a visionary technologist whose impact will be felt for decades.
