Top 10 Costliest Software Bugs

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6. Therac-25 Medical Accelerator

This device was built for radiation therapy by the AECL and CGR in France. Unfortunately, the Operation System was designed and planned by an under-experienced programmer. The power of the electron beam reached such a high power that it lead to the death of 5 patients and injured the rest for the rest of their lives.


7. Multidata Systems

Multidata System International designed a software which would help them calculate the radiation dosage for each patient. Such softwares have certain limitations which the doctors tried to remove by ‘tricking’ the system. The software then started recommending double the dosage needed by the patient. Fixing the software and compensating the injured patients was expensive- to say the least.


8. Patriot Missile Bug

A Missile System was installed in 1991 during the Gulf War for the purpose of protecting certain groups from missile attacks fired by the Iraqi troops. However, a software bug did not calculate the time correctly because of which some targets were ignored. Needless to say, the money which was invested in the system was lost and about 100 people died.


9. An Almost World War III

A Soviet Union satellite created panic by interpreting some reflections as missiles launched by the United States. Protocol required the Soviet Union to launch nuclear arsenal towards the US. Thankfully, Lt. Col. Stanislav Petrov realized that there was some mistake and prevented the initiation of another world war.


10. Mariner I Space Probe

When a programmer was entering a navigation computer code, he made the mistake of omitting one superscript bar. The computer lost control while trying to fix the ‘errors’ during the launching period. After 237 seconds, Mission Control realized the mistake and destroyed it. Over 18.2 million dollars were lost.

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