Dr. Sega has had an extensive career in government service, academia and research. He graduated from the U.S. Air Force Academy in 1974 as a distinguished graduate. His active-duty assignments included instructor pilot and Department of Physics faculty member at the U.S. Air Force Academy. He entered the Air Force Reserve in 1982 with the 901st Tactical Airlift Group at Peterson Air Force Base, Colo., serving in a variety of operations positions. From 1987 to 2001 he served at Air Force Space Command in several assignments, including Mission Ready Crew Commander for satellite operations for the Global Positioning System, Defense Support Program and Midcourse Space Experiment. A command pilot with more than 4,000 flying hours, he retired from the Air Force Reserve in 2005 as a major general, last serving as the reserve assistant to the Chairman of the Joint Chiefs of Staff.
Dr. Sega joined NASA as an astronaut in 1990, making his first shuttle flight in 1994 aboard the Space Shuttle Discovery. From November 1994 to March 1995, he was NASA's Director of Operations, Russia, responsible for managing NASA activities supporting astronaut and cosmonaut training for flight on the Russian Mir space station. He completed his second shuttle flight in 1996 as payload commander for the third shuttle/Mir docking mission aboard Atlantis, completing his astronaut tenure with 420 hours in space.
Since 1982, Dr. Sega has been a faculty member in the Department of Electrical and Computer Engineering at the University of Colorado at Colorado Springs with a rank of professor since 1990. In addition to teaching and research activities, he was Technical Director of the Laser and Aerospace Mechanics Directorate at the U.S. Air Force Academy's F.J. Seiler Research Laboratory, and Assistant Director of the Space Vacuum Epitaxy Center, including management of the Wake Shield Facility Flight Programs at the University of Houston. Dr. Sega was the Dean of the College of Engineering and Applied Science at the University of Colorado from 1996 to 2001. In August 2001, he was appointed as the Director of Defense Research and Engineering, Office of the Secretary of Defense, serving as chief technical officer for the Department and the chief adviser to the Secretary of Defense and Under Secretary of Defense for Acquisition, Technology and Logistics for scientific and technical matters. Dr. Sega has authored or co-authored more than 100 technical publications, has served on numerous local, regional and national advisory and governance boards, and he is a Fellow of the American Institute of Aeronautics and Astronautics and the Institute of Electrical and Electronics Engineers.
- 1974 Distinguished graduate, Bachelor of Science degree in math and physics, U.S. Air Force Academy, Colorado Springs, Colo.
- 1975 Master of Science degree in physics, Ohio State University, Columbus
- 1982 Doctor of Philosophy in electrical engineering, University of Colorado
- 1974-1982, U.S Air Force pilot, instructor pilot, and Physics Department faculty member (U.S. Air Force Academy, Colorado Springs, Colo.)
- 1982-1985, Assistant Professor, Department of Electrical and Computer Engineering, University of Colorado at Colorado Springs
- 1985-1990, Associate Professor, Department of Electrical and Computer Engineering, University of Colorado at Colorado Springs (1987-1988, Technical Director, Lasers and Aerospace Mechanics Directorate, Frank J. Seiler Research Laboratory, U.S. Air Force Academy, Colorado Springs, Colo.; 1989-1990, Assistant Director for Flight Programs, Space Vacuum Epitaxy Center, Associate Research Professor in Physics, University of Houston, Texas)
- 1990-1991, Astronaut candidate, NASA, Lyndon B. Johnson Space Center, Houston, Texas
- 1991-1996, Astronaut, NASA, Lyndon B. Johnson Space Center, Houston, Texas (1990 -1996, Adjunct Professor of Physics, University of Houston, Texas)
- 1996-2001, Dean, College of Engineering and Applied Science, University of Colorado at Colorado Springs
- 2001, acting Assistant to the Secretary of Defense for Nuclear, Chemical and Biological Programs, Office of the Secretary of Defense, the Pentagon, Washington, D.C.
- 2001-2005, Director of Defense Research and Engineering, Office of the Secretary of Defense, the Pentagon, Washington, D.C
- 1982-2005, U.S. Air Force Reserve officer, pilot (302nd Tactical Airlift Wing), space operator (Air Force Space Command), and reserve assistant to the Chairman of the Joint Chiefs of Staff
- 2005-present, Under Secretary of the Air Force, Washington, D.C.