Except that, as far as I know, their main source of revenue is government contracts.
And Elon Musk just testified to Congress to propose having SpaceX put military satellites in orbit at much lower cost (and with more American-built parts...) than Boeing/Lockheed Martin's "United Space Alliance".
I'm just noting nothing in libertarianism opposes space exploration per se, unlike National Endowment for Arts which is a direct antithesis to libertarianism.