In the year 2058, an anomalously expanding red giant Sun threatens to engulf the Earth within 100 years. Under a world government, humanity has constructed 12,000 enormous fusion-powered "Earth Engines" to thrust Earth out of the Solar System. Before his mission aboard the Navigation Platform International Space Station, Chinese astronaut Liu Peiqiang leaves his son Qi in the care of his father-in-law Han Zi'ang. Half of humanity, mostly chosen by lottery, has moved underground; the others died from the cold and cataclysms resulting from the halt of the Earth's rotation as the planet was thrust from orbit further from the sun.