Reaching the Stars
There are no known proposals for interstellar travel yet. But, a plan has been proposed in 2017 for a fly-by of the nearest star, which has a potentially inhabitable planet circling around it. This plan received $100M seed funding, and none of its elements are impossible. Specific solutions have not been proposed to some of the tactical details.
Also, Webb Space Telescope (next step after Hubbel) launched in 2021 at a $10B budget (10x overbudget).