Morgan was selected as the backup candidate for the NASA Teacher in Space Program on July 19, 1985. From September 1985 to January 1986, Morgan trained with Christa McAuliffe and the Challenger crew at NASA's Johnson Space Center, Houston, Texas. Following the Challenger accident, Morgan assumed the duties of Teacher in Space Designee. From March 1986 to July 1986, she worked with NASA, speaking to educational organizations throughout the country. In the fall of 1986, Morgan returned to Idaho to resume her teaching career. She taught second and third grades at McCall-Donnelly Elementary and continued to work with NASA's Education Division, Office of Human Resources and Education. Her duties as Teacher in Space Designee included public speaking, educational consulting, curriculum design, and serving on the National Science Foundation's Federal Task Force for Women and Minorities in Science and Engineering.
Selected by NASA in January 1998 as the first Educator Mission Specialist, she reported for training in August 1998. Astronaut Candidate Training includes orientation briefings and tours, numerous scientific and technical briefings, intensive instruction in Shuttle and International Space Station systems, physiological training, and ground school to prepare for T-38 flight training, as well as learning water and wilderness survival techniques. Following a period of training and evaluation, she will receive technical assignments within the Astronaut Office before being assigned to a space flight.