He has worked at NASA Marshall Space Flight Centre, USA, for about 2 years as NRC Senior Research Associate during 2004-2005. He initiated the research in planetary sciences at SPL and has contributed to the development of planetary science activities in ISRO/DOS and planning of planetary missions of India. He was the Principal Investigator (PI) of SARA experiment on the first Indian Lunar mission Chandrayaan-1, which has revolutionized our understanding on the interaction of solar wind with the Moon through several new findings. He is the PI of MENCA experiment on the Indian Mars Orbiter Mission (MOM). He and his team have PI-lead experiments on Chandrayaan-2 Orbiter and Lander missions as well as Aditya-L1 mission. He has been an observer on Chandra and XMM-Newton X-ray Observatories, Hubble Space Telescope, and Giant Meterwave Radio Telescope (GMRT).
His research field is planetary and space sciences. He has made several contributions in the field of solar system X-ray astronomy, including discovery of X-rays from the rings of Saturn and X-ray flares from Jupiter and Saturn, and theoretical modelling of aurora and airglow emissions and photochemistry in planetary upper atmospheres and ionospheres and comets. His research findings have led to several Press Releases by NASA and European Space Agency, Cover pages of American and European journals, and American Geophysical Union Journal Highlights. Dr. Bhardwaj has over 120 refereed publications and several chapters in books, including a Chapter in the “Encyclopedia of the Solar System”. Dr. Bhardwaj has supervised several Ph.Ds as well as M.Tech. and M.Phil. students, and provided guidance to M.Sc. students and Summer Research Fellows of Indian Academies. He was the Editor-in-Chief of Advances in Geosciences (Planetary Sciences) during 2005-2011, and on Editorial Board of Planetary and Space Science (Elsevier). Currently he is a member of Editorial Board of Space Science Reviews (Springer) and Molecular Astrophysics (Elsevier), and is Associate Editor of Advances in Space Research (Elsevier). He is a member of several ISRO, national and international committees on planetary and space sciences.
Dr. Bhardwaj has received many awards and honours, including Shanti Swarup Bhatnagar Prize (2007), Nehru Centenary Lecture of Kerala Academy of Sciences (2007), ISRO Team Achievement Award for the Chandrayaan-1 (2008), Indo-Swedish Project Award from Swedish Research Council (2010), Indo-Swiss Joint Research Programme (ISJRP) Fellowship (2010), ISRO Merit Award (2012), AOGS Planetary Science Distinguish Lecture, Japan (2014), Dr. P. R. Pisharoty Memorial Lecture of the Kerala Science Congress (2015), Distinguished Alumnus Award (2015) from Indian Institute of Technology (BHU), INSA-Vainu Bappu Memorial Award (2016) and Infosys Prize in Physical Sciences (2016). He is an elected Fellow of Indian National Science Academy (2010), Indian Academy of Sciences (2009), National Academy of Sciences India (2014), as well as of Kerala Academy of Sciences, and Indian Geophysical Union. He is also an elected member of the International Academy of Astronautics and International Astronomical Union. He was elected President of Asia Oceania Geosciences Society (AOGS) Planetary Science for 2006-2010 and is currently the Vice-Chair of COSPAR Commission B.