Assuming the Voyager and Pioneer probes don't get flung into a star, plummet into some super gas giant, or captured into orbit by any other celestial object, these probes may be our fist step in preserving our legacy into the future. Assuming Voyager is still intact with its present trajectory, it will reach the star AC+79 3888 in about 40,000 years
In 40,000 years, there's a good chance that humanity would have gone extinct for a plethora of reasons. It comforts me to know that we would not go the way of the dinosaurs, quietly into oblivion on a lonely corner of the Milky Way. Damn it, at least we tried.