Avul Pakir Jainulabdeen Abdul Kalam was born in a Tamil Muslim family on October 15, 1931. His father, Jainulabudeen was a boat owner and mother Ashiamma, a housewife. The family resided in Rameswaram in Tamil Nadu. Kalam came from a humble background and started working at an early age to support his family. All pictures/AFP

Mathematics held a special place in Dr APJ Abdul Kalam's life and he spent hours studying his favourite subject. After completing school, Dr APJ Abdul Kalam distributed newspapers to financially contribute to his family. However, his interest in learning the subject dwindled by the time he completed his degree in 1954.

Dr APJ Abdul Kalam studied physics at the St Joseph's College, Tiruchirappalli, from where he graduated in 1954 and did Aerospace Engineering at the Madras Institute of Technology, Chennai in 1960. The former President also wished to serve in the Air Force but failed to make the cut by a narrow margin. He stood ninth and only eight positions were available.

Dr APJ Abdul Kalam joined Defense Research and Development Organisation (DRDO) as a scientist and started his career by designing a small helicopter for the Indian Army. He was also part of the INCOSPAR committee working under Dr Vikram Sarabhai, the renowned space scientist.

In 1969, Dr APJ Abdul Kalam was transferred to the Indian Space Research Organisation (ISRO) where he was the project director of India's first indigenous Satellite Launch Vehicle (SLV-III) which successfully deployed Rohini satellite near earth's orbit in July 1980. In his two-decade stint in the space agency, Dr Kalam was responsible for the evolution of ISRO's launch vehicle programme, particularly the PSLV configuration.

Dr APJ Abdul Kalam rejoined DRDO in 1982, and planned the programme that produced a number of successful missiles, earning him the "Missile Man" nickname. He took up the responsibility of developing indigenous weapons as the chief executive of the Integrated Guided Missile Development Programme (IGMDP). He was responsible for the development and operationalisation of Agni and Prithvi missiles.

From 1992 to 1997, Dr. APJ Abdul Kalam was a scientific adviser to the defence minister and later served as a principal scientific adviser (1999-2001) to the government with the rank of a cabinet minister. He played a prominent role in the country's 1998 nuclear weapons tests, Pokhran-II, which established Kalam as a national hero.

In 1998, Dr. APJ Abdul Kalam put forward a countrywide plan called Technology Vision 2020, which he described as a road map for transforming India from a less-developed to a developed society in 20 years, and called for, among other measures, increasing agricultural productivity, technology as a vehicle for economic growth, and widening access to health care and education.

Dr APJ Abdul Kalam is popularly known as the 'Missile Man of India' for his work on the development of ballistic missile and launch vehicle technology. He played a pivotal role in India's Pokhran-II nuclear tests in 1998. He was honoured with the Padma Bhushan in 1981 and the Padma Vibhushan in 1990 for his work with ISRO and DRDO and his role as a scientific advisor to the Government.

One of India's best-known scientists, Dr. APJ Abdul Kalam was full of ideas on how to solve India's problems - on bridging the rural-urban divide through his pet concept of PURA or "Providing Urban amenities in Rural Areas - for empowering villages, and also to use solar power in a big way to tide over India's energy needs. From November 2001, Dr APJ Abdul Kalam was a professor, technology, and societal transformation at Anna University, Chennai.

Dr APJ Abdul Kalam was elected the President of India in 2002. During his term as the President, from July 25, 2002, to July 25, 2007, he was affectionately known as the People's President. Dr Kalam was the third President to have been honoured with a Bharat Ratna, before becoming the President, the earlier two were Dr Sarvapali Radhakrishnan (1954) and Dr Zakir Hussain (1963).

Dr APJ Abdul Kalam enumerated five traits that a leader, especially the president of India, must have. "The leader must have a vision. Without vision, you cannot be a leader. Second, the leader must be able to travel into an unexplored path. Normally the tendency is for people to travel along with well-laid-out ways. Third, the leader must know how to manage success, and even more importantly, failure. The fourth trait is that the leader should have the courage to make decisions. Fifth, the leader should have nobility in management. Every action of the leader should be transparent. And finally, the leader should work with integrity and succeed with integrity.

Among the many books written by Dr. APJ Abdul Kalam, few of them are: Wings of Fire: An Autobiography in 1999, Ignited Minds: Unleashing the Power Within in 2002, Target 3 Billion in 2011, and My Journey: Transforming Dreams into Actions in 2013. Dr. Kalam advocated plans to develop India into a developed nation by 2020 in his book India 2020: A Vision for the New Millennium in 1998.

Dr. APJ Abdul Kalam is known for his motivational speeches and interaction with the student community in India. One of his inspiring quotes is, "Thinking is progress. Non-thinking is stagnation of the individual, organisation, and the country. Thinking leads to action. Knowledge without action is useless and irrelevant. Knowledge with action converts adversity into prosperity."

On July 27, 2015, at 6.35 pm, former President A.P.J. Abdul Kalam passed away after collapsing during a lecture at the Indian Institute of Management in Shillong. Earlier, while climbing a flight of stairs, he experienced some discomfort but was able to enter the auditorium after a brief rest. He collapsed only five minutes into his lecture. On July 30, 2015, the former president was laid to rest at Rameswaram's Pei Karumbu Ground with full state honours.