When China’s DRO-A and B satellites were launched, their rocket failed to deliver them to their planned orbit. Even worse, the satellites were spinning out of control, unable to properly charge their solar panels. Engineers realized that there was still a way to put them on course again. They executed a series of gravitational slingshots over 123 days, using the Sun, Earth, and the Moon to raise the spacecraft’s orbits and put them into their proper trajectory.