New Delhi, Oct 15 (ANI): Prime Minister Narendra Modi has greeted former President, Dr APJ Abdul Kalam, on his birthday on Wednesday. "Birthday greetings to our former President Dr. APJ Abdul Kalam. May he be blessed with good health and a long life," said Prime Minister Modi. Dr Kalam is celebrating his 83rd birthday today. He assumed office as India's 11th President in 2002. He also worked as an aerospace engineer with Defence Research and Development Organisation (DRDO) and Indian Space Research Organisation (ISRO).