I'm a little surprised that billionaires haven't already done things like launched a couple more Hubble telescopes. The design is already done and debugged, just clone it, and launch it. The same for several other successful interplanetary probes - build a (relatively) cheap fleet of clones of successful designs, and send them out to explore the solar system fully. Heck, you don't even have to come up with all the mo…
The Keck telescopes are named after the W.M. Keck foundation, and the Sloan Digital Sky Survey is named after the Alfred P. Sloan foundation, for example.
Space based observatories are still an enormously expensive (billion dollar) endeavor and are generally quite risky.