Voyagers in Space

Voyagers in Space, written by Cheryl Reif -Snyder.

《太空旅行者》，谢丽尔·赖夫-斯奈德 著

One tough job. When the two Voyager spacecraft launched in 1977, they had a tough job ahead. Their mission was to explore Jupiter and Saturn, two of the solar system's giant outer planets. During their journey, they would face freezing temperatures and powerful radiation. If something broke, the space probes would just have to make do with what they had.

一项艰巨的任务 1977年两艘旅行者号航天器发射时，它们面前就摆着一项艰巨的任务 它们的任务是探测木星和土星，这两颗都是太阳系的巨型外行星 旅途中，它们要面对极低的温度和强烈的辐射 如果零件出故障，这两台空间探测器只能依靠现有设备勉强运行

Scientists designed the Voyagers to be tough. Radiation shields and computer -controlled heaters protected their instruments. The spacecraft also carried backups of important equipment, such as the thrusters used for steering. Their computers were programmed to deal with problems that might happen. Computers in 1977 were very different from today's machines, though. Modern smartphones have about 7 ,500 times more computing power and 240 ,000 times more memory than those operating the Voyager spacecraft. Scientists guessed that the Voyagers would only last about five years in space. More than 35 years later, the twin spacecraft are still sending information back to Earth.

科学家把旅行者号设计得十分坚固耐用 辐射防护罩和电脑控温加热器保护着它的探测仪器 航天器还携带了重要设备的备份，比如控制方向的推进器 它们的计算机提前写入了程序，用来应对可能发生的故障 不过，1977年的计算机和现在的计算机差别非常大 现代智能手机的计算能力是操控旅行者号的计算机的约7500倍，内存更是它的24万倍 科学家原本推测，旅行者号在太空只能运行大约五年 三十五年过去了，这对双胞胎航天器依然在向地球传回信息

Planning The Voyager launches were carefully timed. In the late 1970s, the four outer planets' orbits placed them in nearly a straight line. With the planets so close together, it became possible to visit several of them during the same trip. However, the spacecraft still had to travel billions of miles. Unfortunately, the rockets that launched the voyagers into space could only get them to Jupiter, about halfway to Saturn. Scientists solved that problem by using Jupiter's strong gravity to give the spacecraft a boost as it passed by. This technique is called a gravity assist.

发射规划：旅行者号的发射时机经过了精心安排 20世纪70年代末，四颗外行星的轨道让它们几乎排成了一条直线 因为行星距离这么近，旅行者号可以在同一次旅程中探访多颗行星 不过，航天器仍然需要航行数十亿英里 遗憾的是，发射旅行者号的火箭只能把它们送到木星，这里距离土星还有一半路程 科学家解决了这个问题：让航天器飞掠木星时，借助木星的强大引力获得加速 这项技术叫做引力助推

The main task. At first, the Voyager's mission was to study Jupiter and Saturn, their larger moons, and Saturn's rings. The spacecraft carried cameras and scientific instruments including sensors for radiation, magnetic fields, and plasma. Using these instruments, the Voyagers collected information that changed how we understand our solar system.

核心任务 最初，旅行者号的任务是研究木星、土星、它们的大型卫星以及土星环 航天器搭载了相机和多种科学仪器，包括辐射、磁场和等离子体传感器 借助这些仪器，旅行者号收集到的信息改变了我们对太阳系的认知

Jupiter. The Voyagers' first target was Jupiter, the solar system's largest planet. Scientists had already studied Jupiter through telescopes, but the Voyagers sent back new information. They showed that the Great Red Spot was a huge storm that constantly rotated counterclockwise. They discovered a faint ring surrounding Jupiter, similar to those that orbit Saturn. They also found that Jupiter's moons are different from each other and from other planets' moons. For example, the moon Europa is covered by a sheet of ice that scientists think might hide an ocean. Io, another of Jupiter's moons, is covered with volcanoes that shoot gas and dust 306 kilometers, 190 miles above its surface. Before the Voyager missions, the only known active volcanoes in our solar system were on Earth. Scientists now know that Io is 10 times more volcanically active than all of Earth.

木星 旅行者号的第一个目标是太阳系最大的行星——木星 科学家早就通过望远镜研究过木星，但旅行者号传回了全新的信息 它们证实大红斑是一场巨大的风暴，一直在逆时针旋转 它们发现木星周围也有一圈暗淡的环，和土星的行星环类似 它们还发现，木星的卫星各不相同，和其他行星的卫星也不一样 比如木卫二欧罗巴，表面覆盖着冰层，科学家认为冰层下可能藏着一片海洋 另一颗木星卫星木卫一艾奥，表面遍布火山，喷发出的气体和尘埃能冲到表面以上306千米（190英里）的高空 在旅行者号任务之前，我们只知道太阳系里地球有活火山 如今科学家发现，木卫一的火山总活跃度是整个地球的十倍