Your "interstellar species" should be "interplanetary species" as we have no way to get people to another star. We totally lack the ability to make an independ

Your "interstellar species" should be "interplanetary species" as we have no way to get people to another star. We totally lack the ability to make an independent biosphere, and without that the term "interplanetary" is rather meaningless. The Trieste bathyscaphe made it to the bottom of the ocean but we do not have underwater colonies, nor seasteading. Even our colonies on Antarctica are highly subsidized national prestige projects. If "multiplanetary" is something like "can get to another planet and back" then the Manned Venus flyby proposal shows we could have done that with 1970s technology. But there's a reason no one visited the Challenger Deep in the 52 years between Trieste and the Deepsea Challenge - remote exploration is cheaper and safer. We haven't even gotten someone out to the Moon's orbit since 1973.