Mr. Suresh Chandra Tapde (18 February 1940 – 26 March 2021) (L2022)

Last month (26th March 2021) we lost a highly accomplished ASI member, Mr. Suresh Chandra Tapde. Mr. Tapde's contributions to post independence communication and astronomy initiatives in India are immense and lie in the field of engineering. He played key roles in building the first large indigenous radio antenna (a 30 m antenna in 1977), the largest indigenously built optical (the 2.3 m telescope at Kavalur) and radio telescopes (the 45 m GMRT antennas). We are sharing an obituary penned by Prof. Rajaram Nityananda. It has also been published by the Wire.

Of Antennas and Telescopes: Remembering an Engineer for all seasons

Suresh Chandra Tapde (18 February 1940 – 26 March 2021)

On April 12, 2021, more than fifty people current at past staff from premier research organizations across the country “gathered at” the National Centre for Radio Astrophysics in Pune for a memorial meeting. The quotes give away the online nature of the meeting which is the post pandemic norm. This was sixteen days after the passing of Suresh Chandra Tapde in Pune. Held a few days after the usual thirteen days, the meeting nonetheless marked the traditional transition from mourning to acceptance, remembrance, and in this case, celebration of a life of singular achievement.

Tapde, as he was universally known, played a key role in some of the proudest space communication and astronomy initiatives in post independent India. His journey started in the late 1960’s, with the construction of the first indigenous large antenna (30 metres diameter, a good size even by today’s standards) for satellite communication at Arvi. In 1977, he moved to the challenging 2.3 metre optical telescope project of IIA at Kavalur, where he spent a decade. This was the first optical telescope to be made in India, and remains the largest optical telescope ever made in India and was the workhorse for Indian optical astronomers for the last several decades. On the completion of this, he moved to what was surely his greatest challenge - construction of the Giant Merewave Radio Telescope, an array of thirty 45 metre sized antennas, with an unproven design (the brain child of Govind Swarup) aimed at providing unprecedented high specifications despite an extremely tight budget. The GMRT, commissioned in 2000, was, and remains, one of the most sensitive radio telescopes in the world. Speakers at the memorial meeting recounted witnessing the sparks fly between between Govind Swarup and Tapde and fearing the consequences for the GMRT project. Greatly to the credit of both men, these sparks, instead of setting off an inferno, lit a bright flame that continues to illuminate even today.

One stringent test of the person and the work is what happens after retirement. As the reminiscences unfolded, it became clear that Tapde’s superannuation in the year 2000 only cemented his position as the go to expert for engineering projects linked to astronomy and space. These included the 32m deep space antenna for ISRO, as well as the unique multi-mirror gamma ray telescope MACE built by BARC. He played an important role in the project management board of the 3.6m optical telescope at Devasthal, even though towards the end, his health made it difficult for him to travel. In every case he was sought out by people who knew him intimately, often people he had mentored earlier. They valued his vast experience, sharp and quick technical insight and ability to think out of
the box. Equally important, he was frank - with the rare ability of calling a space a spade and yet not giving offence, listening closely to everyone. He would find the best way forward drawing on all inputs, and more often than not, had the last word in the numerous meeting he attended. These skills were surely honed in the projects he had managed, though “manager” does not do justice to his role and contribution to his mentoring of a whole generation of engineers across a range of projects.

Goethe described architecture as “frozen music”. At the opposite end we have the restless engines powering our equally restless movement on land, sea and air. The structures Tapde worked with fall precisely between these extremes. When still, they rise majestically like the best architecture. Yet they exist to move - usually slowly, to follow a distant object in the heavens, or a spacecraft on its way to the Moon or Mars. This movement has to be smooth and precise, not to upset the geometry and integrity of the reflecting surface which brings the light or radio waves to a focus. When high winds threaten, the same structure has to swing quickly to a safe position, and for optical telescopes, shelter behind a large dome. All this is built to last decades. All branches of engineering - civil, mechanical, electrical, control, electronics, combine to fulfil this goal. In theory, the person entrusted with such a project is like the conductor of an orchestra - he does not write the score, he does not play a single instrument, and yet he has to understand everything and deliver a seamless whole. In real life, the boundaries become blurred and move - there is feedback from the ultimate users to the designers, the constraints of the people on the ground, and the supply chain from many industries., a complex and shifting terrain, that Tapde deftly negotiated through the decades.

Tapde’s style and personality were a key to his enormous contributions. He was a meticulous planner, who systematically organized his own working space and time, even amidst external chaos. His attention to detail, discipline, meticulous planning and tight scheduling were legendary. These are part of the stereotype of the cold dispassionate engineer or “techie” to use the current term. Sharing a journey and sitting in a meeting with Tapde, both of which I have done more than once, would however quickly dispel any such preconceptions. His quick purposeful movements, smiling face, intense engagement, witty observations, and occasional philosophical reflections and comments on the world around us would give a glimpse of the man behind the work. To those who knew him for decades, there was far more to him, than just an extremely competent engineer. They included people not just from IIA and NCRA, but BARC, ECIL, TCE, all of whom had been touched by him, professionally and personally.

The world knows the people who had the vision to conceive of these projects - Vikram Sarabhai, Vainu Bappu, Govind Swarup. Tapde was the right man in the right place at the right time to catalyse the transformation of these visions into reality. The world should know him more.