Each about the size and weight of a subcompact automobile, the Voyagers epitomize 1970s high tech. Their computers are weaker than those in today’s digital watches, their analog TV cameras more primitive than the ones that shot Laverne & Shirley. But they made history at every planet they reconnoitered—confirming, as Voyager chief scientist Ed Stone put it, that “nature is much more inventive than our imaginations.”

Yet it almost didn’t happen.

I remember when these missions launched. What an incredible accomplishment that they are still sending back data.