Bengaluru: Renowned Indian space scientist U.R. Rao passed away here in the early hours of Monday, said a space agency official. He was 85.

"Rao passed away at his residence around 3 a.m., after prolonged illness and due to age-related health issues," the official of the Indian Space Research Organisation (ISRO) told IANS.

Rao, who was the chairman of the state-run ISRO for a decade from 1984 to 1994, leaves behind his widow, a son and a daughter.

"Rao was in a private hospital till recently for treatment as he had a heart ailment and was recovering at home. Our (ISRO) doctors were attending to him," said the official.

ISRO Chairman A.S. Krishna Kumar, senior space scientists and many officials of the space agency rushed to Rao's house to mourn his death and console his bereaved family.

"Saddened by the demise of renowned scientist, Professor U.R. Rao. His remarkable contribution to India's space programme will never be forgotten," tweeted Prime Minister Narendra Modi.