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Software Disasters

This is a list of software disasters where bugs had real-world repercussions beyond typical annoyance.

Mariner 1 rocket

Transcription mistake sent rocket off-course

Hartford Coliseum Collapse

CAD software didn’t take into account wet snow

Therac-25

Race condition gave lethal doses of radiation

1983 Soviet early-warning ballistic detection system

Software did not account for false detections from clouds, nearly started WW3

Knight Capital Trading glitch

Insufficient cleanup of program artifacts, lack of testing, and lack of monitoring led to $440 million loss in 30 minutes.

1990 AT&T Outage

Single line of code knocked out a single switch, shuts down national phone network

1991 Patriot system

Miscalculation of trajectory because of rounding error

Pentium FPU (f00f bug)

Floating point instruction halts processor

Cyrix Coma bug

Unprivileged instructions send processor into infinite loop, requiring reboot

https://en.wikipedia.org/wiki/Cyrix_coma_bug

Arianne 5

64-bit to 16-bit conversion, causing an overflow that knocked out the guidance system. Backup system had identical problem.

Y2K bug

Shortening year to two digits causes overflow at turn of century

2038 bug

32-bit time_t overflows in year 2038

Mars Orbiter

Mismatch of metric and imperial measurements puts orbiter wildly off-course.

Virtual Case File

Less a case of any one bug, and more program mismanagement. $170 million spent before program scrapped. A case study in why following software engineering best practices matters.

https://en.wikipedia.org/wiki/Virtual_Case_File