NASA’s farthest-out solar-powered probe, the Juno spacecraft, successfully entered orbit around Jupiter tonight after a five-year, 1.8 billion-mile cruise through interplanetary space – and many hours’ worth of high tension back on Earth.
Mission managers at NASA’s Jet Propulsion Laboratory in California had to program Juno’s computer in advance to execute a 35-minute rocket engine firing that put the probe in the correct orbit. If anything went wrong, Juno could have zoomed right past Jupiter, and flight controllers couldn’t have done anything about it.
It took 48 minutes for signals to travel from the spacecraft to Earth at the speed of light, which meant no one on Earth knew that the engine burn had even started until 13 minutes after it was over. Mission managers said the engine burn was just 1 second off what was planned.