I am no longer a junior, but would have been upset to be tasked with refreshing the old historical obsolete laundry (no matter how sacred or distinguished), expecially when I already had experience delivering safety critical products packing much more modern technologies.

The opportunity they would be offering is not rare at all! The opportunity to research and design something truly new on the other way is very scarce.

What have you worked on that is as cool as a space probe that's cruising in interstellar space and still collecting valuable data?

There are a lot of things as cool as, done by people I know, such as the gyros on the Webb telescope, the APU in the F-35, or a small rack-mountable Cesium reference clock, but there aren't many opportunities like that.