Interview: Dr. Vishnu Viswanathan (NASA, ECE-2011)

  1. Please elaborate on your profile and describe a typical day in your work. What is the most challenging part and how do you equip yourself to face such challenges?

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.

  1. What motivated you to pursue a master’s in Space Systems Engineering after majoring in ECE in your undergrad? What/Who were your inspirations back in college to start working in your present domain? Did you take up any project in this domain during your BTech?

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.

  1. What was the motivation behind pursuing your higher education in Europe? How do you think the culture around education in Europe is different from the US? 

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 Ph.D. 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.

  1. The decision to opt for a Ph.D. is a very crucial one. What, in your opinion, is the right time to decide?

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.

  1. What are the alternate trajectories to build careers that the people willing to work in NASA can follow? How is the growth outlook for fresh grads from India to be able to work at NASA?

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. 

  1. What are the challenges faced by a research scientist while trying to understand the interior structure of planetary bodies?

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.

  1. What can one learn about the interior of the Moon from the laser data?

An intuitive example: If we knew the variations in 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.

  1. What is the dynamic model of the Moon? How do scientists use lasers to model celestial objects dynamically?

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

  1. Are there any citizen scientist-based projects where one could learn about the geophysical nature of planets?

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.

  1. Given the recent advancements in the field of CubeSat engineering, what kind of payload designs should the current college students aim at?

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 light weight. They are generally deployed in low earth orbit for remote sensing and communication applications. 

  1. Can laser-ranging techniques be extended to deduce the ephemeris of asteroids?


  1. Since you also have teaching experience at Grad and undergrad level, how has your perspective changed being on the other side? Is there something you’d suggest to students you wished you knew when you were a student?

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

  1. Many fresh Ph.D. graduates have a dilemma whether to get postdoctoral research experience before applying for positions in academia. How does one decide whether to pursue a postdoctoral position before applying for jobs in academia?

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.

  1. Have you come across any mental roadblocks along the way? How did you stay focused throughout your extensive education?

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.

  1. How has your experience and extracurriculars at NIT-T shaped your career growth? How was your experience volunteering for social causes and do you continue to find avenues to do the same?

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.

  1. What do you think are the inadequacies in research in India, and specifically in NIT-T?

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.

  1. In retrospect, what are some things about your career path that you wish you knew from college and could have done better?

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 favorable situations that were mostly backed by hard work and persistence. At the same time, learning from unfavorable situations was also vital. So, I am not sure how I would have done differently, let alone better.

  1. How do you interface with other domains of work when working in your domain? How do you suggest people make themselves adaptable to interdisciplinary projects?

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.

  1. What would you like to say to the current B-Tech undergraduates interested in a career in astrophysics?

“Pale. Blue. Dot.”

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

This interview was taken in collaboration with Nakshatra NIT-T.


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