I just looked up the colloquial definition of brat. It seems that I certainly am brat. Read my book when it comes out & you'll know that's true. But why would someone label Cassini brat and JWST not brat?

JWST is a shiny new pleasure to have in class (big comm windows) and a joy to operate (massive bandwidth). Cassini couldn't chew gum (collect science) and walk (had to turn the entire thing around to point at Earth) at the same time. (I do mission ops at JPL)