While I hardly think that George Santayana's statement: "Those who cannot remember the past are condemned to repeat it." applies to research or space programs, I still think it is interesting and fun (at least to me) to look back at the many concepts and ideas that have been put forward for allowing my favorite field, radio astronomy, to "slip the surly bonds of Earth (John Gillespie Magee, Jr.)." Unfortunately, at present those bonds, as well as the funding agencies, seem particularly "surly."
However, let me look back over the history of space-based and Moon-based concepts and plans since the late 1960s and early 1970s (my stated span of ∼40 years) from the successfully launched and operated Radio Astronomy Explorers (RAE A & B) to the newest concepts for the Radio Observatory for Lunar Sortie Science (ROLSS) and the Dark Ages Lunar Interferometer/Lunar Array for Radio Cosmology (DALI/LARC).
The deep science questions to be explored at frequencies below the Earth's ionospheric cutoff (∼<10 MHz) or shielded from the Earth's pervasive radio interference (back-side of the Moon) have been explored in great depth and detail and with outstanding competence by others, so I will only try to give a broad-brush description of many of the concepts that have come before.
Even though I have been personally involved with a lot of the concepts over the past ∼25 years and am still waiting for one to "fly," I remain optimistic for the future.