However, he was awarded a scholarship by former chairman of PAEC Nazir Ahmad to continue his higher studies, and travelled to United States.
There, he attended North Carolina State University where he received his double MSc in Physics and MS in Electrical engineering in 1959.
While studying at Oak Ridge National Laboratory, his mentor Dr. Bill Nelson has called him one of his brightest and finest students in his doctoral teaching experience.
Mehmud who was working at an Oak Ridge National Laboratory as a nuclear engineer was asked by Dr. Ishrat Hussain Usmani to go to Pakistani Embassy at the Washington, D.C., and met with Professor Abdus Salam.
According to his interview, Mehmud expressed his concern over joining NASA and clearly notified Abdus Salam about his willingness to work in Pakistan's nuclear industry.
However, with Salam's insistence, Mehmud and Mustafa visited NASA's headquarter and examined the American advances in rocket technology.
Mehmud came back to Pakistan where he carried out his research in rocket science and satellite launch vehicles under the supervision of Wladyslaw Turowicz.
On 15 December 1980, with the support of PAEC Chairman Munir Ahmad Khan, President of Pakistan General Zia appointed Salim Mehmud as chief executive officer of SUPARCO and asked him to submit necessary recommendations for up-gradation of SUPARCO to the status of a full-fledged Commission.
Zia who was a strong advocate for the space program, allowed SUPARCO to developed the indigenous satellite capabilities.
As a profession, Mehmud is a nuclear engineer, and designed the missile in a complex model that the rocket can carry approximately up to 500 kg HEU fissile material.
It was his leadership that in 1989, 23 March, on the Republic Day of Pakistan, SUPARCO, along with Engineering Research Laboratories, publicly tested the Hatf Missile.
Mehmud's profile has been kept in secrecy but it is known that he has work in Pakistan's aerospace weapon development program agency, DESTO.
However, it is known that he has played a "father-like" role in the establishment of the Sonmiani and Tilla spaceports and have been a scientist behind the Pakistan's solid-fuel rocket firing program during the 1960s.