Well we have 2 spacecrafts that have now traveled to the end of our solar system (42 years now) and so far no evidence of any aliens, at least that we have heard about.
Both Voyager 1 was built to explore the outer solar system, Voyager 2 was built to explore the outer planets. Neither was designed to look out into interstellar space.
That’s beyond our solar system - they both exited some time ago and are now in “interstellar space”
Those probes are about the size of a Honda Fit.
Space is pretty darned big.