Shriharikota, Dec 18 (ANI): Prime Minister Narendra Modi congratulated ISRO on the successful liftoff of India's heaviest rocket on Thursday. PM tweeted "Successful launch of GSLV Mk-III is yet another triumph of brilliance and hardwork of our scientists,Congrats to ISRO for the efforts."Meanwhile, Chairman of ISRO K Radhakrishnan congratulated his team for their hard work.