The nation is proud of ISRO’s achievement of successfully launching the indigenously-developed GSLV-Mk III, India’s heaviest rocket, President Pranab Mukherjee said on Monday. “The GSLV-Mk III is the heaviest rocket ever made by India and is capable of carrying the heaviest satellites made till date. The nation is proud of this significant achievement,” the President said in a message to A S Kiran Kumar, Secretary, Department of Space, Chairman, Space Commission & Chairman, ISRO.