In conversation with Dr Vishnu Viswanathan

Transitioning to a distinct STEM field requires a deep understanding of one’s strengths and passion. Read further to find more about the journey of Dr Vishnu Viswanathan, a Research Scientist at NASA!

I am a research scientist at NASA Goddard Space Flight Center, and my current research focuses on:

1. The analysis of tracking data such as laser, radio, and images to understand the interior structure and dynamics of planetary bodies.

2. The analysis of orbital and rotational dynamics using gravity and topography data.

3. Development of planetary and lunar ephemerides.

A typical day involves making progress on at least one of the above activities, which could mean reading research articles, bouncing off research ideas, coding, writing, and reviewing articles and proposals. The most challenging part is to find the right balance between the time spent on these activities requiring multiple context switching while navigating through time-constrained priorities. In general, it is hard to be good at something you really wish you’d know how to do without having the experience to do it. In such situations, either ask for advice from those with experience; or if you are the first to encounter such a problem, then try, fail miserably multiple times, rinse off emotions, repeat with tweaks until you become good at it. The latter strategy works almost all the time.

One of the main reasons I took up ECE in my undergrad was because I was excited about space/satellite communication. However, it took a while before such relevant courses came about, and when they did, it seemed minimal from my expectations. I had wished there were more subject electives during my undergrad, but having been involved with teaching activities, later on, I am aware of the challenges associated with offering wider options early on. After four years of undergrad (and a lack of job opportunity in my subjects of interest at that time), I was more curious to learn than when I had begun with. This led to my Masters, Ph.D., Postdoc to leading research that connects several of these new topics towards perhaps lifelong learning and discovery experiences. Several friends, teachers, professors, acquaintances, and experiences back in college and school have influenced my interests in these subjects. No current-domain-related projects during BTech.

I was late before I made up my mind for higher education and that reduced my options very dramatically. My frantic efforts paid off (perhaps pure luck). The more polished answer (which is equally true) is that I wanted to follow my interest and curiosity, even if it seemed unconventional and unrelated to most (but clearly, I was not prepared for it). Discovering those interdisciplinary links within the subjects that I eventually got to learn was very rewarding. I wouldn’t be able to speak for the whole of Europe, but France was totally worth my time. Language barriers pushed me out of my comfort from day one, and cultural differences opened my mindset. Professionally it was rewarding to do a master’s from the aerospace hub of Europe and later a PhD from the house of Arago and Le Verrier. I spent most of my time in the south of France close to the Nice Observatory (my host research institution), after which the evolution model of our solar system is named(did I forget to mention the French Riviera?). I wouldn’t be the right person to comment on education in the US.

I would say earlier the better. However, several other factors such as hard work, persistence, commitment, grit, curiosity, desire to learn, and many others not listed here, determine if you would enjoy and be successful. If you are willing to go through Q1 answer’s “latter” strategy, I can assure you that the rewards are equally priceless.

When I first came to NASA, I can tell you that I felt a strong “imposter syndrome.” With time, I found out that most people within NASA did not have a straightforward (single discipline) career path, unlike I expected. This was strangely comforting. I have had colleagues at NASA tell me that there is no “one” course out there to prepare for the kind of work we do. I found this to be true. Most subjects have some space-related applications. If you think there is no apparent link, you may be en route to finding a new interdisciplinary subject that could also be of interest to space-faring nations. So, you might as well enjoy this knowledge pursuit than specifically build careers to work for specific organizations/companies/institutions. Enjoy the ride. Instant gratification isn’t sweet enough. There are no shortcuts at learning.

Non-uniqueness of parameter values and estimates along with its manifestations on results, inferences, conclusions.

We send space probes and analyze the data returned to improve our certainty of answers.

An intuitive example: If we knew the variations in the spin of a standard cricket ball vs a similar ball filled with some liquid in space, we can then make some predictions on their interiors by only monitoring their variations in rotation. For the Moon this is done using the analysis of lunar laser ranging data that now span over five decades (1969-present). Lunar laser ranging uses laser light pulses to make high-precision measurements of the distance between the Earth and Moon surfaces. The laser pulses sent from Earth are reflected by retroreflectors installed on the Moon during the Apollo (US) and Lunokhod (Russian) missions. By monitoring multiple reflectors on the Moon’s surface, we are able to track, analyse and predict the orientation of the Moon as well as infer its interior structure.

The dynamical model refers to the time-integrated model of the orbital and rotational motion of the Moon which depends on the various dynamic forces acting on the Moon from other planetary bodies. Laser data are used to fit such dynamical models.

That is a good question. There could be, but not a generic one as far as I know. Reach out to me with specifics if interested.

Again, no generic answer to it as far as I know. Most CubeSat missions address a particular issue, and hence the payload design must cater to the mission requirements, I would imagine.

A CubeSat is a miniature satellite designed in certain constraints of mass and volume. Their dimension generally is 10 cm x 10 cm x 10 cm and they are extremely lightweight. They are generally deployed in low earth orbit for remote sensing and communication applications.


Yes. Please be nice to your teachers and professors. It is likely that they chose that profession to share the joy of knowledge.

A postdoc opportunity, if chosen wisely, can help build and expand your academic and research network (in addition to the experience gained). Hopefully, your network enables you to find the job you seek.

Normally, all days aren’t as sweet as I described above. Persistence helps wash away some of those mental roadblocks. Finding a healthy support mechanism (e.g., friends and colleagues) softens self-doubt and reinforces self-confidence. Experiences taught me about the consequences of not staying focused, and that learning seemed to have stuck around.

Those extracurriculars may have encouraged me to try out something new, even if I had no clue how to start. So yes, they should be added to my list of career influencers. Unfortunately, I have not been able to keep up active involvement as of now to social causes, but I try to compensate in whatever little passive way I can.

I have not conducted any of my research in India (although I’d like to). So, I wouldn’t be the right person to report any inadequacies or lack thereof. From social forums, I find that NIT-T has come a long way since our graduation (a decade ago!), and I am certain that any remaining inadequacies are being actively addressed.

None noted. In my case, it is likely that being at the right place at the right time had its positive effect. Still, there were also times involving active planning to place myself in favourable situations that were mostly backed by hard work and persistence. At the same time, learning from unfavourable situations was also vital. So, I am not sure how I would have done differently, let alone better.

A lot of reading, acknowledging one’s ignorance, remaining curious, and most importantly, forgiving yourself when you make mistakes in a subject you are unfamiliar with.

“Pale. Blue. Dot.”

Even though we are all going through unprecedented times, we now have a better understanding of how to pursue higher education when it comes to the space science sector. Thanks to Dr Vishnu Viswanathan for taking out time to answer our most pressing doubts about the field and helping us see a future full of possibilities!

Dr Vishnu Viswanathan can be reached at his email or at his Twitter handle @lunascientist.

Looking Beyond the Stars!

This interview was taken by Nakshatra NITT in collaboration with Feeds, NIT Trichy.

A student-run university-wide organization for sparking awareness and fascination in astronomy. Interested contributors can contact us by email.

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