I don't disagree that Google and Facebook do enormous amounts of difficult engineering (I recently saw a USAF slide which compared Google's R&D spending on soft

I don't disagree that Google and Facebook do enormous amounts of difficult engineering (I recently saw a USAF slide which compared Google's R&D spending on software to the entire defence industry's). But the Apollo program and the Manhattan project were something else. Arguably they represent the historical highwater marks in terms of megaprojects which had effectively unlimited resources in the face of wide-open, unsolved problems.