Reusable Rockets

Thousands of rockets have flown into space, but not until 2015 did one return like this: it came down upright on a landing pad, steadily firing to control its descent, almost as if a movie of its launch were being played backward. If this can be done regularly and rockets can be refueled over and over, spaceflight could become a hundred times cheaper.

Two tech billionaires made it happen. Jeff Bezos’s Blue Origin first pulled off a landing in November; Elon Musk’s SpaceX did it in December. The companies are quite different—Blue Origin hopes to propel tourists in capsules on four-minute space rides, while SpaceX already launches satellites and space station supply missions—but both need reusable rockets to improve the economics of spaceflight.

Blasting things into space has been expensive because rockets cost tens of millions of dollars and fly once before burning up in a free fall back through the atmosphere. SpaceX and Blue Origin instead bring theirs down on fold-out legs, a trick that requires onboard software to fire thrusters and manipulate flaps that slow or nudge the rockets at precise moments.

SpaceX has the harder job because Blue Origin’s craft go half as fast and half as high and stay mostly vertical, whereas SpaceX’s rockets have to switch out of a horizontal position. A reminder of how many things can go wrong came in January, when SpaceX just missed a second landing because a rocket leg didn’t latch into place. Even so, it’s now clear that the future of spaceflight will be far more interesting than the Apollo-era hangover of the past 40 years.