I recently encountered the phrase “penetrate the crust” in the context of a Russian drilling program. In the context it was clear that what was meant was “pass completely through the crust into the mantle”. (The earth’s crust is the rocky outermost layer of the planet, whose thickness varies between 5 and 50 kilometres. It overlies the softer mantle, a layer that is about 3000 km thick.)
A bit of google tells me that this use of penetrate to mean pass completely through is not terribly rare.
Normally, I would use the word penetrate to indicate that the thing penetrated had been breached even slightly. So, in the drilling case, if you’ve passed all the way through the crust and into the mantle, what you’ve done is penetrate the mantle. Or I might say that you’ve penetrated the Crust-Mantle boundary.
What say you?