Stella is astounded by the stars. But her brother Ryan is bored with space already. Less than a week into their family holiday on the Space Hotel orbiting Earth, he's moaning that there's nothing to do. Their parents suggest the two of them go on an excursion to the International Space Station Museum. But during the space walk, disaster strikes. A massive solar flare sends a deadly wave of electromagnetic radiation hurtling towards the Earth. In the panic to return to the Space Hotel, Ryan's jet-pack malfunctions and Stella has to rescue him before he spirals off into deep space. With only minutes before the solar flare hits, they're forced to shield themselves inside the ISS. The solar flare short-circuits its systems and causes the ISS to drift out of orbit. With all radio communications dead, Stella will need her knowledge of the stars and a whole galaxy of luck to return safely to Earth.