Yeah, I remember reading somewhere that they have extremely strict standards at NASA, to the point that multiple reviews are mandatory on even single line changes for mission critical systems.

Here's an example: http://spinroot.com/gerard/pdf/P10.pdf

And another: http://lars-lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf

Dunno how closely these are followed in day-to-day operations, but they clearly put some thought into it.