Former defence minister Zhang Aiping died of an undisclosed illness in Beijing on Saturday. He was 93 years old. Zhang, who was appointed defence chief in 1980, was best known for his work with China's missile and space programme. He also played a key role in the building of the nation's first atomic bomb. 'China's conventional arsenal lags far behind that of the United States. But it still can compete with the US thanks to its missile and nuclear weapons,' said Hong Kong-based military expert Ma Ding-shing. 'General Zhang had been in charge of these developments and his contributions cannot be ignored.' Zhang joined the PLA at 19. He fought in the civil war and anti-Japanese war in the 1930s and 1940s. He was responsible for organising the first naval force under the People's Republic and was promoted to general in 1955. Zhang was put in charge of missile and satellite technology during his tenure as the head of the Commission of Science Technology and Industry for National Defence. He was promoted to defence minister and vice-premier in 1980.