Director of Uttaranchal Space Application Centre Dr Anil Kumar Tiwari was shot dead by an unidentified person near his residence, police said on Sunday.
Tiwari, who was shot at and critically wounded on Saturday night, succumbed to injuries in hospital on Sunday evening, they said.
The incident happened when the scientist was returning home after attending a party, police said.
A man, who was yet to be identified, approached Tiwari outside his Mohit Nagar house and fired a single shot at him after a brief altercation.
The bullet pierced Tiwari's chest, police said, adding he was immediately rushed to a private hospital where an operation was conducted to remove the bullet.
His condition, however, deteriorated and he died in the evening.
Expressing shock over the incident, Chief Minister ND Tiwari said an inquiry had been ordered into the incident.