Aaron came to NASA as a flight controller with the responsibility of Electrical, Environmental and Communication Systems. With the launch of Gemini 2 he was already working in the Control Panel.
Aaron is awarded, that he saved the Apollo 12 mission after the missile has been struck by lightning. He also played an important role in the rescue of Apollo 13, Apollo 13 It was shown by Loren Dean in the film.
Later he worked on the Skylab program and helped in the development of software for the space shuttle. He was manager of the Johnson Space Center 's Space Station Project Office 1989. Aaron was forced to resign in 1993 after he was accused that he had exceeded the budget by 500 million U.S. dollars.
Aaron was 1993 Manager at Johnson Space Center 's Engineering Directorate, and remained there until his retirement in 2000.