[JoeAltmaier]

But most engineering projects don't have hundreds of millions of moving parts. At that scale, standard practice becomes intractable.

The Space Shuttle went up the first time with a few K of core memory. The software effort was really pretty trivial compared with systems today.

[dpitkin]

The article is from 1996 but even then they were far beyond a few K.

"Take the upgrade of the software to permit the shuttle to navigate with Global Positioning Satellites, a change that involves just 1.5% of the program, or 6,366 lines of code. The specs for that one change run 2,500 pages, a volume thicker than a phone book. The specs for the current program fill 30 volumes and run 40,000 pages."

[JoeAltmaier]

The brain of NASA’s primary vehicle has the computational power of an IBM 5150, that ’80s icon that goes for $20 at yard sales. According to NASA and IBM, the shuttle’s General Purpose Computer (GPC)—which controls, among other things, the entire launch sequence—is an upgrade of the 500-kilobyte computer the shuttle flew with until 1991.

  --  http://www.popsci.com/node/31716

[JoeAltmaier]

My point exactly. That process can't work unless you have millions to spend.