Finally came across an article which describes now is software written for spacecrafts.
In the modern software environment, 80% of the cost of the software is spent after the software is written the first time — they don’t get it right the first time, so they spend time flogging it. In shuttle, they do it right the first time. And they don’t change the software without changing the blueprint. That’s why their software is so perfect.
Software is getting more and more common and more and more important, but it doesn’t seem to be getting more and more reliable.
money is not the critical constraint: the groups $35 million per year budget is a trivial slice of the NASA pie, but on a dollars-per-line basis, it makes the group among the nation’s most expensive software organizations