The most expensive hyphen in history
One of the first costly (literally) computer errors was the one that caused the Americans to lose the Mariner-1 probe ship heading towards Venus. It happened in 1962.
The launch vehicle began to deviate from the design trajectory immediately after the launch from Cape Canaveral. NASA management had to make a decision to blow up the launch vehicle, as the rocket could well have fallen into the populated territory. As a result - a failure of the program of space researches and fireworks in cost of 80 million dollars, in so much cost of creation of the spaceship.
Of course, they began to look for the perpetrators. And soon it turned out that the whole thing was in a single hyphen. It was simply missed during the preparation of the text of the program to be entered into the computer, which controlled the rocket flight. By the way, the program was written in Fortran, and the unfortunate hyphen, in the words of the famous science fiction writer Arthur Clarke, became "the most expensive hyphen in the world. Still, 80 million dollars.
By the way, another problem with rocket technology, caused by a software error, occurred in the 90s. This time, brave American military rocket scientists who took part in Operation Desert Storm suffered. To their surprise, the Patriot missiles used to intercept Iraqi missiles in the air periodically passed the target. The trial began after a missed Iraqi missile resulted in the death of 28 U.S. soldiers. Initially, there was a suspicion that some of the Patriots were technically defective.
However, the commission established on this occasion was surprised to find out that all the missiles examined were absolutely functional. You have probably already guessed where the mistake was hiding? Of course, in the software used by the American anti-aircraft missile system. It turned out that the system was designed with the expectation that its continuous operation time would not exceed 14 hours, but in practice, the complexes worked continuously for 100 hours or more. It seemed to be nothing, but it turned out that the software used to determine the time accumulated errors. In 100 hours of operation, the difference was 0.34 seconds. Programmers, it turns out, knew about it, but considered the fact immaterial.
Killers in white coats
The next completely horrible story about software bugs occurred in Canada in 1987.
And it is related to the Atomic Energy of Canada Limited (AECL) Thorac-25 medical device, which was used for radiation therapy of cancer patients. As in previous cases, the software on the ill-fated machine contained errors. As a result, between 1985 and 1987, several dozen patients treated with Thorac 25 received an increased dose of radiation, and four of them were tragically treated under computer control.
An independent examination conducted at the insistence of relatives showed that the reason for this was mistakes made by AECL programmers. And something, according to the manufacturers, of course, was caught at the development stage, but "insignificant", from the point of view of the company's engineers, errors in the software still remained. Nancy Leveson and Clark Turner, who was conducting an independent investigation, wrote down in their report: "The main conclusion from this is that focusing on finding individual errors in the program does not guarantee that the system as a whole will function unambiguously.
By the way, it's scary to even think what would have happened if the medical equipment software had been written by the creators of Windows, a system famous for its many errors and constant hang-ups. The population of the Earth today would be half as large as its current size.
The 1990s: a series of errors
The nineties were marked by the mass introduction of computers into everyday life. Accordingly, computer failures began to occur more frequently and their consequences became more extensive.
One of the first computer system failures, which was felt by the whole country, was the failure of the computer system of long-distance call processing of AT&T company in 1990.
Because of this, the company's subscribers were deprived of the opportunity to call other cities and countries for almost 9 hours, and the malfunction itself became perhaps the largest in the history of the existence of this telecommunications company.
Searching for an answer to the question of why the system malfunctioned, eventually, led to a single line of code, which caused the failure. Alas, the joking statement that every program contains at least one error has once again received practical confirmation.
To be continued in the next part
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