Many of the largest undertakings. (Here's one counter-example - the world's first transatlantic cable: https://en.wikipedia.org/wiki/New_York,_Newfoundland_and_Lon...).

The mistake many libertarians make is to argue that government is inherently incompetent. This viewpoint contradicts reality. Government agencies which attract smart people can be as successful as any private company. Large private companies can be as bureaucratic as any government agency.

The fundamental difference is that there's no way to get rid of bloated and ineffective government organisations. NASA is a good example: in the 1960s it was the place where every bright young engineer and scientist wanted to work, but over the decades it stagnated into another bureaucracy dominated by non-technical folk chasing pork-barrel funding.