BBC made a series called The Planets (2019) that talks about almost all space probes from the last 30 years and the data retrieved so far, you might have access to that but not sure of your country.
Do you mean that the website is not available outside of the U.S.? "The Farthest" is also on Netflix, but I don't know about non-US availability. It's also available for rent/purchase on Youtube. https://www.youtube.com/watch?v=Cu3kuUB1sOQ. If all else fails, it's available on DVD -- I bought two copies myself so I can loan it to friends without worrying about it being lost.