Explanation:

• The Defence Research and Development (DRDO) Chairman G Satheesh Reddy flagged off the first Production unit of Heavy Weight Torpedo (HWT), Varunastra .
• The Varunastra has been designed and developed by Naval Science & Technological Laboratory (NSTL) of DRDO while Bharat Dynamics Limited (BDL), Vishakhapatnam has manufactured the torpedo for the Indian Navy.