Okoye returned to Nigeria in 1965 after completing his doctorate and began lecturing in physics at the
University of Ibadan. In 1967, just before the
Nigerian Civil War, he joined the
University of Nigeria, Nsukka. In 1972, he founded the university’s Space Research Center and was appointed Professor of Physics in 1976 Okoye returned to Cambridge in 1971 as a Commonwealth Academic Staff Fellow at the
University of Cambridge. He was a visiting
fellow at the Institute of Astronomy (IoA). At the IoA, working under the supervision of
Fred Hoyle,he developed advanced mathematical techniques and pursued theoretical solutions to contemporary problems in astrophysics. During this period, he deepened his knowledge of plasma physics, general relativity, and cosmology, while establishing his own research direction in high-energy astrophysics. His work included publications on X-ray data from radio galaxies and on the jet of M87. As part of his commitment to educational development, he facilitated the donation of laboratory teaching equipment from the Department of Physics at Cambridge to the
University of Nigeria, and secured school equipment from an educational charity for a school in
southeastern Nigeria region, aiding post–civil war recovery efforts. Between 1978 and 1989, Professor Okoye held several key positions at the
University of Nigeria, including Director, Division of General Studies. Head, Department of Physics and Astronomy, Associate Dean and Dean of the Faculty of Physical Sciences. He served as Acting Vice-Chancellor
University of Nigeria from June to September 1978 as well as the
Royal Astronomical Society of the United Kingdom. He was a member of the
Pugwash Conferences on Science and World Affairs, the
New York Academy of Sciences, the
International Network of Engineers and Scientists for Global Responsibility, and the
International Astronomical Union. Okoye was a part-time consultant to the
United Nations on the development of
space science and technology in developing countries from 1979 to 1986. Okoye was a visiting scientist at the
Max Planck Institute for Radio Astronomy Bonn,
Germany from August to October 1986. From 1990 to 1993, he was appointed a Commonwealth Academic Staff Fellow at the
University of Cambridge and served as a visiting professor and senior research fellow at the
Institute of Astronomy, and fellow commoner at Churchill College at the University of
Cambridge. In December 1993, Sam was seconded from the University of Nigeria to the Federal Government and the World at the Cross-roads: Towards a Sustainable, Equitable and Liveable World. Okoye was a columnist for
The Guardian (Nigeria) which he wrote for more than four years. His columns, which focused on information technology as well as advances in scientific ideas, drew a wide readership because of his ability to convey difficult scientific ideas in accessible language. Okoye served Nigeria in a number of capacities, including: • Member of the Federal Government delegation to the
World Administrative Radio Conference in Geneva, Switzerland, 1979 • Member of the Federal Government delegation to the United Nations Conference on Peaceful Uses of Space in Vienna, Austria, 1981; • Member of the Federal Government Panel charged to produce an integrated energy policy for Nigeria (1984); • Member, Governing Council, Anambra State University of Science and Technology (ASUTECH) (1988–1989); • Pioneer Science attaché,
High Commission of Nigeria, London, United Kingdom (1993–2000); • Director,
National Agency for Science and Engineering Infrastructure (NASENI) and Federal Ministry of Science and Technology (1993–2000). ==Space Research Center==