An endowment isn't free money and launching a telescope into space remains a costlier venture than plopping a few arrays on a mountain range like Mauna Kea or the Chilean Andes. Contrary to your imagination, radio telescopes aren't that cheap either. The Smithsonian and NASA fund most of the construction, operation, and maintenance of Harvard's telescopes rather than the university. Suffice it to say, it's unlikely an academic institution will find economically viable route to launching space telescopes any earlier than twenty years from now.