2018年某月某日,在距离地面300千米的高空,一艘载有4名航天员的飞船正在地球低轨道盘旋。飞船下方,是地球蔚蓝色的曲线;上方,则是闪烁着点点星光的浩渺太空。突然,飞船后方喷出一条闪亮的火舌,将飞船极速推向前方。5分钟后,飞船已经加速到每秒11.2千米,并且挣脱了地球的束缚,向着它的目的地——月球飞去。 One day in 2018, a spacecraft carrying four astronauts is hovering over the Earth’s low orbit at a height of 300 kilometers from the ground. Below the spacecraft, is the blue curve of the earth; above, is the vast space glittering with a little starlight. Suddenly, a glittering flare was ejected from the back of the spacecraft, pushing the spacecraft to the front in great speed. Five minutes later, the spacecraft has accelerated to 11.2 kilometers per second and has freed itself from the shackles of the Earth towards its destination, the Moon.