Governments are quite often rather inefficient, but they are really large. For example, rockets could not have been developed by private enterprise, because it took something like thirty years (and substantial investment) to build somewhat reliable rockets. [1]

A bit more abstract: businesses are good at small incremental development steps, since most of the steps need to have a market. In contrast a government can invest in projects which are both very long term and very expensive, because they have a reliable revenues (taxes).

[1]much longer version of the argument: http://www.slate.com/articles/technology/future_tense/2011/0...