When he returned to MIT, Atwood married Sue Harian, a graduate of Tufts University, and completed his bachelor's and master's degrees in electrical engineering.

In 1952, Atwood and an associate, Fred Best, founded Dynatrol Corporation, a research company that developed and built inertial navigation and guidance systems for ballistic missiles.

In 1959 General Motors purchased the company, including 50 employees along with Atwood to obtain the valuable navigation and guidance system technology.

In 1961, Atwood was appointed director of engineering of Milwaukee operations of AC Spark Plug, a manufacturer of the Norden Bombsight and similar instruments during World War II.

In 1970, Atwood was appointed the Indianapolis (Indiana) Operations Manager for the newly formed Detroit Diesel Allison Division of GM.

Also in 1985 he was named executive vice-president of General Motors and in 1987 he was made vice-chairman of the General Motors board; a member of the board's finance, executive and administrative committees; responsible for Electronic Data Systems (EDS), GMHE, and GM's Technical Staffs and GM corporate Information Management.

Atwood's management and scientific skills were thought to be a complement to those of the Defense Secretary appointed, John G. Tower, who was expected to play a political and policy-setting role.

Atwood spent 30 minutes explaining to an anxious 20 million viewers what was happening with the Apollo 8 astronauts as they circled incommunicado around the far side of the Moon on Christmas Eve morning, 1968.

Much of its technical staff was working on low volume or one-off programs, in the design and construction of commercial digital systems for General Motors plants, and internal manufacturing support.

Atwood took that faith into negotiations with General Motors and the other GM divisions who also thought that it was their destiny to control their systems with their own electronics design.

"His Tenure saw the collapse of Soviet communism and the triumph of liberty in Eastern Europe, the victory of U.S. and allied forces in Desert Storm, and the first years of downsizing of America's defense establishment", Perry said in a statement.

[5] "In tackling tough tasks facing him, Don impressed everyone with his patience, good humor, and commitment to maintaining a strong, ready U.S. military", Perry said.