Fair point. But not so "last minute" that a pre-existing military design couldn't be investigated and reworked, custom print heads cast, etc. That puts it back to...what? 1979 or 1980? In that era, "let's build it to our exacting specifications, high tolerances, and unique mission requirements" pervaded NASA / aerospace engineering and procurement. However much we admire it today, COTS was not their way, and wouldn't be for at least another decade.