Launius received his bachelor's degree in American History from Graceland College, Lamoni, Iowa, in 1976. Then he received a Master of Arts in American History from Louisiana State University, Baton Rouge, in 1978. In 1982 Launius earned his Doctor of Philosophy in American History from Louisiana State University, Baton Rouge.
From 1982 to 1990 Launius held several positions as civilian historian with the United States Air Force. From 1990 to 2002 he was the chief historian for National Aeronautics and Space Administration (NASA). Since 2002 he was Chair of the Division of Space History at the Smithsonian National Air and Space Museum, Washington, until 2006. From 2006 until 2013 he was Senior Curator, and from 2013 to 2016 Launius was Associate Director for Collections and Curatorial Affairs at the same institution. He retired in 2016.
Meanwhile, Launius also served as an instructor and adjunct professor at various universities, including McKendree College, Weber State University, Graceland College, Anne Arundel Community College. Besides, he served as consultant to the Columbia Accident Investigation Board in 2003. He has also been a regular commentator on space-related issues for the news media.
Launius is a member of the Community of Christ.
Launius is a member of the Organization of American Historians, American Historical Association, American Astronautical Society (chairperson of History Committee since 1992, then vice-president for publications since 1995, member of executive committee since 1995), American Astronomical Society, Society for the History of Technology, Society for History in the Federal Government, Society for Military History, National Council for Public History, Mormon History Association (president, 1993-1994), Western History Association, John Whitmer Historical Association (president, 1990-1992).
Roger married Vianne Tiffany on January 4, 1976. They have 2 children: Dana Kristine, Sarah Anne.