The early 1960s were a heady time, as I recall. The "space race" was on between the USSR and USA, and everyone knew about Yuri Gagarin and Alan Shepard. The submarine Trieste visited the Mariana Trench, deepest spot in the ocean, in 1960and no one returned there until 2012. And in early 1961, Project Mohole set out on a quest to drill through the Earth's crust into the underlying mantle.
Project Mohole did reach the top of the crust, just underneath 200 meters of seafloor mud. But that proof-of-concept exercise was the end of ituntil now. Over 50 years later, the deep-sea drilling program now called the Integrated Ocean Drilling Program or IODP has set a plan in motion that will return to this task. With all we've learned since 1961, the new Mohole project will very likely succeed. Read more about it in my new article.