There’s so much cool stuff that was rejected before I was even born. It’s kinda bizarre how the space program is so in the dumps now.
The space shuttle, while expensive, was at least an icon. I grew up with it as a symbol of US spaceflight hegemony. Now NASA is just a really expensive organisation achieving very little.
> NASA is just a really expensive organization achieving very little.
Granted, human spaceflight is crazy expensive. And yet...
Jet Propulsion Labs, to pick a single NASA site, has never been more busy. I counted 30 spacecraft listed as "active" on their Current Missions page, but I think I missed a couple of them.
NOTE: I don't think that web page of 'Current' missions is up to date.
For instance, the VSOP project is still on there; that was using a spacecraft designed mostly by JAXA, I believe, as an element of the Very Long Baseline Array (VLBA).
I was still attending the VLBA Operations meetings, early 2000's, and at that time it seemed that they were winding that project down. Data reduction and analysis of VLBA itself had been difficult to implement and wasn't totally integrated into the standard software package. Adding a telescope that was moving at orbital velocity made things quite spicy. I found it to be a profoundly humbling experience.
It's wild to think the world of 2001 A Space Odyssey seemed very possible to the people of the late 1960's. They went to the moon in only about 10 years, so a Jupiter mission in another 30 years would just be a continuation of current progress. Little did they know that humans would lose the capability to leave orbit just a few short years later.
Related; a proposal to do a Venus flyby with Apollo hardware: https://en.wikipedia.org/wiki/Manned_Venus_flyby