Mark your calendars! September 9 is declared debugging day. It’s been associated with bug removal for over 50 years now, but is rarely officially celebrated. So let’s start the tradition this year.

It all started with a 1947 diary entry by the Mark II Tech Team at Harvard University. The now classic entry features a moth stuck to the page, time stamped at 3:45 pm, with the caption “Relay # 70 Panel F (butterfly) in relay” and the proud bragging “First real bug found. “

Okay, the computer bug story didn’t really start on this date (see “Moth in the machine” for the real story), but nonetheless, her birthday seems like a great time to examine famous bugs and other ghosts. of the machine.

Here is a very selective – and therefore incomplete – collection of infamous software bugs. Unlike the relatively benign story of the moth in the relay, certain insects have wreaked havoc, embarrassment and destruction around the world. Some literally killed people.

Don’t expect this collection to contain stories about the Ping of Death or other loopholes exploited by hackers and malware, like the 2008 Spanair crash or the possibly apocryphal story of the sabotaging CIA. the Soviet gas pipeline. It also won’t include the deliberate decisions of programmers that came back to haunt them later, as with the year 2000.

Instead, this story is about outright programming errors that caused key failures in their own right.

Did I miss something important? Think of this as a call for entries for the Biggest Bugs of All Time. These are my suggestions; if you have honorable mentions bring them. The worst you can do is crush them.

Space bugs

The programming mistakes that derail large-scale space exploration missions – especially the bugs that cause spectacular explosions – are frightening, costly, and embarrassing to those who let them go. They provide extremely vivid reminders for all of us to check and recheck (and recheck and recheck and recheck) every line of code.

The Mars Climate Orbiter does not orbit

Back in physics class, our teachers skipped over all the answers that consisted of a number. If the answer was 2.5, they would take their red pens and write “2.5 what?” Weeks ? Puppies? Demerits? And keep marking the wrong answer.

At the time, we thought they were just pedantic. But it’s the kind of mistake that can burn a $ 327.6 million project in minutes. This was the case in 1998, when the Mars Climate Orbiter built by NASA’s Jet Propulsion Laboratory approached the red planet from the wrong angle. At this point, it could easily have been renamed Mars Climate Bright Light in the Upper Atmosphere, and soon after renamed Mars Climate Debris Drifting Through the Sky.

There were several issues with this spacecraft – its uneven payload made it torque during flight, and its project managers overlooked some important details during several stages of the mission. But the biggest problem was that different parts of the engineering team were using different units of measure. A group working on thrusters measured in English units of pound-force seconds; the others used metric Newton-seconds. And whoever checked the numbers didn’t use the red pen like a pedantic high school teacher.

The result: The thrusters were 4.45 times more powerful than they should have been. If this blunder had been spotted earlier, it could have been offset, but it wasn’t, and the result of this inattention is now lost in space, perhaps in pieces.


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