In my reading travels I came across this article, dated 12-31-1996, about the space shuttle software. 

 

Here is a quote from the article to capture your interest.

 

“As the 120-ton space shuttle sits surrounded by almost 4 million pounds of rocket fuel, exhaling noxious fumes, visibly impatient to defy gravity, its on-board computers take command. Four identical machines, running identical software, pull information from thousands of sensors, make hundreds of milli-second decisions, vote on every decision, check with each other 250 times a second. A fifth computer, with different software, stands by to take control should the other four malfunction.”

 

“They Write the Right Stuff,” by Charles Fishman

 

You can read the full article here: