纪录片《火星任务》 第12期 正确的飞行轨迹(在线收听) |
Oh, nice! 好球 They need to figure out how far 他们要根据 the ball needs to travel depending on where the receiver is. 外接球手的位置判断球应当扔多远 How fast the receiver's running in that direction. 还要考虑外接球手的移动速度 Most quarterbacks don't sit down and calculate that on paper. 四分卫可没时间坐下来拿纸算 Set, go! 准备 开始 It's all done in their head 他们不用多想 instinctively without thinking about it. 而是下意识地做出动作 For spacecraft, 对航天器而言 we do it on paper, or these days, on computers. 我们就得用纸算了 现在是计算机算 The other thing a quarterback does 四分卫还要干的一件事 is put spin on the ball. 就是让球旋转 Spiral so that the ball flies in the correct trajectory. 旋转使球保持正确的飞行轨道 So we also are spinning our spacecraft, 我们同样也会让航天器旋转 so it maintains its attitude... 这样它才能保持姿态 and so that we can point the solar rays back at the Sun 使太阳能板朝向太阳 and communicate back to the Earth. 并与地球保持通讯 And so, the actual rotation of the ball 所以其实橄榄球的旋转 is similar to the rotation of the spacecraft. 和航天器的旋转很相似 They make it sound simple, 听起来很简单 but firing a spacecraft across the solar system 但是让一个航天器在太阳系中穿梭 involves some really complex ballistic calculations. 涉及到极其复杂的弹道学计算 |
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