America's nuclear arsenal is run on an 8-inch floppy disk system from 40 years ago

An airman trains on how to operate the SACCS, which controls the US nuclear arsenal

Huge swaths of the United States' massive nuclear arsenal of over 4,700 warheads are controlled entirely by 1970s-era IBM Series/1 software running on 8-inch floppy disks.

As we reported earlier, the news came in testimony presented to the House Oversight Committee by the US Government Accountability Office (GAO). The report detailed aging legacy infrastructure systems used by various federal agencies, including the Department of Defense and US Strategic Command (STRATCOM).

According to the GAO, the Strategic Automated Command and Control System (SACCS) - which controls the coordination and operation of ICBMs, nuclear bombers, and nuclear submarines - is operated entirely on an IBM Series/1 computer.

The Department of Defense (DOD) reports the age of the SACCS system as 53 years old, meaning it was designed in 1963. The system attained operational capability in 1968, and went through several software iterations and improvements before the DOD settled on the IBM Series/1-based system after the computer was introduced in 1976.

The IBM Series/1, which has a 16-bit architecture, was created with mechanical operation in mind. The computer saw use in manufacturing environments by private companies such as General Motors, as well as by numerous US military agencies, including as a mainframe system for several Marine Corps programs.

According to the GAO, the Department of Defense plans to "update its data storage solutions, port expansion processors, portable terminals, and desktop terminals by the end of fiscal year 2017." The DOD plans to completely replace the dated system by 2020.

The 8-inch floppy disks used in the nuclear command system have a storage size of 237.25KB - enough to store roughly 15 seconds of audio, or 47% of a compressed JPEG.

But according to the Pentagon: if it ain't broke, why request a federal appropriation to fix it?

"This system remains in use because, in short, it still works," Pentagon spokeswoman Lt. Col. Valerie Henderson told AFP. "However, to address obsolescence concerns, the floppy drives are scheduled to be replaced with secure digital devices by the end of 2017."

According to Henderson, "modernization across the entire Nuclear Command, Control, and Communications enterprise remains ongoing."

Photo credit: US Air Force