Fractured and divided as we are, on one thing we can agree: 2015 was a miserable year. The only cheer was provided by Lincoln Chafee and the Pluto flyby (two separate phenomena), as well as one seminal aeronautical breakthrough.
On Dec. 21, Elon Musk’s SpaceX, after launching 11 satellites into orbit, returned its 15-story booster rocket, upright and intact, to a landing pad at Cape Canaveral. That’s a US$60-million ($83 million) mountain of machinery — recovered. (The traditional booster rocket either burns up or disappears into some ocean.)