Story by Mass Communication Specialist 3rd Class Susan C. Damman

The U.S. Navy has a proud history of staying at the forefront of technology. For decades Sailors have pushed the boundaries of progress. Among America’s many accomplished Sailors, Rear Adm. Grace Hopper stands out as an adamant advocate for scientific curiosity and innovation. She was a professor, a mathematician, a pioneer of computer science, and a public speaker. She believed it was important to approach all situations in new and innovative ways.

“Humans are allergic to change,” Hopper said. “They love to say, ‘We’ve always done it this way.’ I try to fight that. That’s why I have a clock on my wall that runs counter-clockwise.”

Grace Hopper already held a doctorate in Mathematics from Yale University when she joined the U.S. Navy Reserve as an officer in 1943 at the age of 37. Before joining, she was a mathematics professor at a time when most women weren’t working outside the home. Very few women attended university at that time and still fewer studied mathematics or science.

Her first assignment after completing Officer Candidate School in 1944 was at the Bureau of Ordnance Computation Project at Harvard University. She was one of the first programmers on the Navy’s Mark I computer.
The Mark I computer was 51 feet long, eight feet tall, and two feet deep. The machine consisted of relays, switches, counters and cam contacts in a specially designed glass case. A long, horizontal continuously-rotating shaft powered the Mark I and hummed like a sewing machine. Computer scientists programmed it using paper tape, with punched holes representing zeroes and ones.

The Navy used the computer to study ballistic weapons trajectories, magnetic fields, and radar. Hopper worked on that project for the duration of World War II. She wrote a manual for the Mark I, which was the first computer manual ever written.

After being released from active duty after World War II, Hopper stayed at Harvard and continued working on the Mark II and Mark III computers for the Navy.

One day the team was having problems running the Mark II. They investigated and discovered a moth trapped in a relay. They taped the moth in the daily logbook. The entry read “first actual case of bug being found.” Hopper joked that it was the first instance of ‘debugging’ a computer and popularized the term ‘debugging.’

In 1949, she went to Eckert-Mauchly Computer Corporation and helped design the UNIVAC I (Universal Automatic Computer), the first computer that could translate numbers into letters.
While working at Eckert-Mauchly, Hopper developed her FLOW-MATIC compiler, the first programming language to emphasize an English-like syntax. It made computer programming more accessible to non-mathematicians.

Hopper served as an advisor to the committee that developed COBOL (Common Business-Oriented Language), based largely on her FLOW-MATIC compiler. By 1960, the Department of Defense, and any company that wanted to do business with them, adopted COBOL as the standard programming language. Hopper earned the nickname Grandma COBOL.

Hopper retired reluctantly from the Navy Reserve in 1966, but she was recalled to service seven months later. The Navy needed her to further standardize COBOL.

Her reinstatement was supposed to be only six months, but the Navy extended her indefinitely. She stayed for another 19 years, reaching the rank of captain in 1973 and commodore (rear admiral lower half) in 1983. Hopper retired for the final time in 1986 at the age of 79. When she retired, she was the oldest active duty commissioned officer in the Navy. She had served for 43 years. At her retirement she was presented the Defense Distinguished Service Medal, the highest non-combat award given by the Department of Defense.

Hopper’s work on compilers revolutionized the field of computer science. Although she could have had a successful civilian career, she chose to serve her country.

“I’ve received many honors and I’m grateful for them,” said Hopper. “But I’ve already received the highest award I’ll ever receive, and that has been the privilege and honor of serving proudly in the United States Navy.”

Hopper died in 1992 at the age of 85. She was buried with full military honors at Arlington National Cemetery.