Cunningham flew as Lunar Module Pilot on Apollo 7 with Wally Schirra and Donn Eisele. Although Apollo 7 carried no lunar module, his position reflected the mission structure NASA was preparing for later lunar flights. The crew spent eleven days in Earth orbit testing the redesigned Apollo command and service module — open definition after the Apollo 1 fire.

Apollo 7 was demanding and sometimes tense, but it proved the spacecraft could support a crew and cleared the way for Apollo 8 to fly to the Moon. Cunningham's role was part of the unglamorous but essential recovery of Apollo after tragedy. After leaving NASA, he worked in business, investing, broadcasting, and writing, including his memoir The All-American Boys.

Cunningham's background fit the broader pattern of the early astronaut corps: technical training, operational discipline, and a career built around difficult work before spaceflight. His formal education included University of California, Los Angeles (B.A. Physics, 1960). His service background is recorded as Colonel, United States Marine Corps Reserve. His personal record also sits alongside a family life recorded as two marriages, two children, a reminder that these careers unfolded within ordinary lives as well as national history.

Cunningham's flown space career centered on Apollo 7, where he served as Lunar Module Pilot. First crewed Apollo flight and first crewed test of the Block II command and service module in Earth orbit. The mission proved the redesigned Apollo spacecraft could support a crew for a lunar-mission-length flight and cleared the way for Apollo 8.