Today, tomorrow, learn English naturally. 天天自然学英语
Oops. NASA Accidentally Points Voyager 2’s Antenna Away from Earth, Temporarily Losing Contact
It’s every space mission’s nightmare: losing contact with the spacecraft. In the best case, you recover it right away. Worst case, you never hear from your hardware again. On July 21, controllers lost contact with Voyager 2, out in the depths of space. Now they’re waiting for a reset to catch Voyager 2’s next message when it “phones home”.
So, what happened? The spacecraft, which is nearly 20 billion kilometers away, seems to be doing fine. It’s probably sending all kinds of communications back to Earth. But, the stream of data is bounding off into space instead of linking up with the Deep Space network. That’s because a series of planned commands to Voyager 2 inadvertently caused the spacecraft to point its antenna 2 degrees away from Earth. Essentially, Voyager 2 and Earth are not in communication. They’re “talking past” each other.
Regaining Contact with Voyager 2
All is not lost. Yet. That’s because the spacecraft is programmed to reset its orientation several times a year to keep the antenna pointed toward Earth. The next reset isn’t for several months—on October 15th. Until then, Voyager 2 is speeding along on its planned trajectory. If all goes well, the control team should hear from the spacecraft again on October 15th. At this point, they’re characterizing this loss of signal as a temporary communications pause. There’s nothing to indicate any other problems with Voyager 2, beyond the mistaken commands.
The spacecraft is equipped with a high-gain antenna measuring 3.7 meters across. It communicates with the Deep Space Network via the S band (13 cm wavelength) channel as well as in the X band (3.6 cm wavelength). At its current distance, the spacecraft’s signals take about 17.5 hours to get back to Earth. That time increases as the spacecraft gets farther away.
A Glorious History
Currently, Voyager 2 and its twin Voyager 1 are exploring space beyond the solar system. They launched in 1977 and for the past decades, they’ve made huge discoveries at planets and the outermost bounds of the heliosphere. Their images and data opened up a whole new way of looking at the outer solar system.
Now, they’re in the Voyager Interstellar Mission phase, where their data helps characterize the “limits” of the solar system lie and where deep space begins. Voyager 2 probably entered interstellar space a few years ago, although it still reports on conditions at the “edge” of the solar system. Interestingly, while Voyager 2 is out of communications with Earth, Voyager 1 is still talking with the Deep Space Network. It’s about 24 billion kilometers from Earth.
Ultimately, they’re headed out on two very different trajectories through the stars. They have enough power to operate for a few more years (2025 or thereabouts) to send back information to Earth about their environments. Engineers on the project have figured out a way to extend spacecraft power for perhaps a couple more years by tapping some specific onboard reserves. Eventually, however, the spacecraft will fall silent as their power supplies run out. This current outage on Voyager 2 is giving mission engineers an early taste of what that experience will be like, after “talking” with these distant spacecraft for nearly five decades.
注释：
bound: v
表示"弹回，反跳，弹起"，means " jump or bounce"，如：Polly came bounding into the room holding a letter. 波利手上拿着一封信,蹦蹦跳跳地跑进了房间。
trajectory: n
表示"轨迹"，means "the path followed by an object moving through space"，如：My career seemed to be on a downward trajectory. 我的事业似乎在走下坡路。
heliosphere: n
表示" 日光层"，means "the region inside the heliopause containing the sun and solar system"，如：The sun has a magnetic field, the heliosphere, which envelops our entire solar system. 太阳也有个磁气圈，就是日光层，它包裹了整个太阳系。
中文简要说明：
美国航天总署（NASA）最近发生了一起重大人为失误，由于操作员传送「错误指令」，导致太空探测器「航海家2号」（Voyager 2）的天线偏离地球，就此与NASA「失联」。现在NASA正想办法与探测器重新联机。
根据英国《卫报》、「今日宇宙」（Universe Today）新闻网站1日报导，「航海家2号」目前所在位置距离地球大约200亿公里。上月21日，NASA操作员无意间发出错误指令，使探测器天线朝地球以外的方向偏转了2度，由于这个误差，地球传出的讯号因此「越过」探测器，无法被接收；反之，探测器传回的讯号，地球也收不到。
负责管理航海家探测器的NASA喷射推进实验室（NASA's Jet Propulsion Laboratory）说，目前他们正透过位在澳洲堪培拉的深空卫星天线（Deep Space Network），持续聆听航海家的讯号，未来一周也会发射大量指令，希望有机会触及探测器，尽快恢复联系。
不过即使这么做行不通，科学家们也不太担心。NASA表示，由于探测器被设计为每年数次重置方向，以保持天线指向地球，因此如果没有其他意外，应该能在10月15日再次接到航海家2号的消息。
1977年，NASA发射航海家1号（Voyager 1）、2号两艘探测器，前者任务为研究木星和土星系统，后者目的则是研究木星、土星、天王星和海王星，堪称最多产的太空飞行器；达成主要任务后，两艘探测器继续往太阳系外飞奔而去，协助人类探索太阳系边界，NASA估计，它们仍有足够动力，可运行至2025年。
航海家1号目前距离地球约240亿公里，是人类发射最遥远的探测器；在2号失联时，1号仍持续与地球进行通讯。
留言微信公众号《自然学英语LearnNaturally》，可咨询更多！