A problem for graphic design is that the official seals and emblems of U.S. government entities are traditionally circular. The name of the agency circumscribes the outside. Often the graphic is a riff on the good old eagle. Many can be quite detailed, in the heraldic sense. All this wreaks havoc on traditional graphic design approaches. "Simplifying" the official seal to make it more compatible with modern needs is probably not the way to go. NASA's seal will probably have to stay somewhat the way it already is -- the formal one, I mean, not the Meatball logo.
The Internal Revenue Service has a logo that's separate from its seal, one of the few large agencies to do so. The logo doesn't try to reproduce the seal or simplify it. It's easily recognizable and designed according to the principles of good graphic design, for purposes such as variable scaling and monochrome reproduction. Yes, I'm sure we could come up with a more timeless logo. But it's legitimately a hard task. This is why companies refresh their logos from time to time. Graphic design, with a few notable examples, always seems to be a product of its time.