航天器着陸彗星有望揭開地球之謎

In a technological feat that gives scientists their first opportunity to dig into a remnant of the early solar system, the European Space Agency’s Rosetta mission successfully placed a small spacecraft on the surface of a speeding comet on Wednesday.

本週三，歐洲航天局(European Space Agency)的“羅塞塔”(Rosetta)任務完成了一項技術壯舉，成功地將一個小型航天器送到一顆高速移動的彗星表面，這給科學家們提供了機會，讓他們首次得以深入探究早期太陽系的殘餘星體。

With this achievement, a comet is no longer a mysterious and sometimes frightening spray of light across the night sky, but another member of the solar system to be explored, like the moon and Mars. The technology of landing on a comet, with its wisps of gravity, could be applied to future efforts to mine asteroids.

從此之後，彗星不再是夜空中劃過的一種神祕可怕的光焰，而是加入月球和火星的行列，成爲太陽系中又一個可以被探索的成員。彗星的引力非常微弱，着陸彗星的技術，未來可以應用到小行星的資源挖掘領域。

The agency’s director general, Jean-Jacques Dordain, described the touchdown on Comet 67P/Churyumov-Gerasimenko, a 2.5-mile-wide ball of rock, ice and dust moving faster than 40,000 miles an hour, as “a big step for human civilization.”

歐航局局長讓-雅克·多爾丹(Jean-Jacques Dordain)說，在67P/丘留莫夫-格拉西緬科彗星上着陸是“人類文明前進的一大步”。該彗星寬約2.5英里，是由岩石、冰和塵埃構成的一個球體，移動時速逾4萬英里。

“Our ambitious Rosetta mission has secured another place in the history books,” Mr. Dordain said at a news conference. “Not only is it the first to rendezvous with and orbit a comet, but it is now also the first to deliver a probe to a comet’s surface.”

“我們的‘羅塞塔’任務充滿雄心，它已經足以名載史冊，”多爾丹在新聞發佈會上說。“這不僅是首次進入彗星軌道，繞着它飛行，而且是首次把探測器送上了彗星表面。”

For scientists, one of the central mysteries that Rosetta will explore is whether Earth’s oceans are filled with melted comets. Since the rocky bits that came together to form the planet were dry, water has to have come from somewhere else. One possibility is that comets slamming into the Earth early on seeded it with water.

對於科學家，“羅塞塔”將要探索的一個主要奧祕是：地球上的海洋是否充滿了熔化的彗星。岩石塊匯聚形成了地球，但它們是乾的，水必定來自其他地方。一種可能性是，彗星在早期撞到了地球，給它帶來了水。

News of the touchdown of the 220-pound lander, named Philae, arrived at the mission control center in Darmstadt, Germany, at 5:03 p.m. local time (11:03 a.m. Eastern time). Cheers erupted.

220磅重的着陸器“菲萊”(Philae)成功着陸的消息，在德國達姆施塔特本地時間下午5時03分（美國東部時間上午11時03分）到達了那裏的“羅塞塔”任務控制中心。歡呼聲驟然響起。

“We’re there, and Philae is talking to us,” said Stephan Ulamec, the manager for the lander. “We are on the comet.”

“我們就在那裏，‘菲萊’在向我們發送消息，”着陸器負責人斯蒂芬·尤拉米克(Stephan Ulamec)說。“我們在彗星上了。”

With that news, a procession of officials from nations and organizations, including NASA, that had collaborated on the $1.75 billion mission reveled in the accomplishment, capping a 10-year, four-billion-mile trip.

得知這個消息後，很多國家和組織的官員歡呼雀躍，因爲歷時10年、長達40億英里的漫漫旅程有了成果。這些組織中也包括美國國家航空航天局(NASA)，它爲這個耗資17.5億美元的任務提供了幫助。

“How audacious!” said James L. Green, the director of NASA’s planetary sciences division. “How exciting! How unbelievable to be able to dare to land on a comet.”

“太猛了！”NASA行星科學部主任詹姆斯·L·格林(James L. Green)說。“太令人興奮了！敢於登上一顆彗星，太不可思議了！

Within the hour, though, a worrisome caveat came to light.

但是，還不到一小時，就出現了令人擔憂的警告。

“It’s not only complicated to land there,” Dr. Ulamec said in a later news conference. “It’s also, as it appears, very complicated to understand what has happened.”

“複雜的不僅是在那裏着陸，”尤拉米克博士在隨後的新聞發佈會上說。“要理解發生了什麼狀況似乎也非常複雜。”

Two harpoons that should have fired into the comet did not, and the lander may not be secured to the surface. Dr. Ulamec said fluctuations in the radio link and the generation of power by the solar panels suggested that Philae may have bounced off the surface before settling down again.

本來應該有兩個魚叉支撐裝置發射到彗星，但卻沒有發射，因此着陸器可能沒有抓牢彗星表面。尤拉米克博士說，從波動的無線電聯繫以及太陽能電池板的發電狀況來看，“菲萊”可能從彗星表面反彈出去，然後再次着陸。

“Maybe today we didn’t just land once, we even landed twice,” Dr. Ulamec said.

“也許今天我們不只着陸了一次，有可能着陸了兩次，”尤拉米克博士說。

As expected, the Rosetta orbiter moved out of the line of sight of Philae, breaking radio communications.

正如預期的那樣，“羅塞塔”軌道飛行器移動到”菲萊”的聯繫範圍之外，無線電通信中斷了。

The orbiter is to re-establish the radio link in the next day, and mission managers hope then to better understand the stability of Philae’s footing.

軌道飛行器將在第二天重新建立無線電聯繫，該任務的負責人希望屆時可以更好地瞭解“菲萊”基腳的穩定性。

Nonetheless, the lander and its 10 instruments have begun 64 hours of scientific operations before its batteries drain. Solar panels will recharge the batteries, allowing intermittent operations over the coming months, about an hour every two days.

儘管如此，着陸器及其10臺儀器已經開始開展科學任務，在電池電量耗盡之前，可以運轉64小時。電池將由太陽能電池板充電，因此在未來數月內，它們每兩天會進行約一小時的間斷性運作。

The landing culminated a tense day as Rosetta maneuvered to the correct position to let Philae go — moments of celebration were interspersed with long, quiet stretches of waiting.

在這緊張的一天中，“羅塞塔”移動到正確的位置，讓“菲萊”脫離了它，而着陸彗星表面是這一天的高潮——人們慶祝了這些時刻，其間則穿插着漫長、靜默的等待。

The operation proceeded despite a few small glitches and one potential showstopper problem: failure of a thruster that was to fire after touchdown to press the lander against the comet’s surface. A pin was supposed to break a wax seal on the gas tank, but repeated attempts did not succeed.

儘管存在一些小失誤和一個可能引起麻煩的問題，任務繼續進行。一個推進器失靈了，它本來會在着陸後發射，把“菲萊”壓在彗星表面上。一個銷釘本來應該打開燃氣罐的一個蠟封，但多次嘗試都沒有成功。

Without the thruster, the washing-machine-size Philae would have to rely on ice screws on its landing legs and the harpoons to anchor it to the comet. The thruster, which was to shoot a stream of nitrogen gas, was intended to counteract not just the possibility of Philae bouncing off the surface but also the upward kick from the firing of the harpoons.

如果沒有那個推進器，洗衣機大小的“菲萊”就只能依靠着陸裝置上的冰錐和魚叉來抓牢彗星表面。這個推進器本來應該噴射氮氣氣流，以便消除“菲萊”彈離彗星表面的可能性，並且抵消魚叉發射時的上推力。

Mission managers decided to proceed because there was no way to repair it.

負責人決定在繼續執行任務，因爲這些問題無法解決。

Philae detached on schedule, for a seven-hour descent.

“菲萊”按計劃進行了分離，降落持續了7個小時。

There was some worrying a couple of hours later when the lander was about 10 minutes late in re-establishing communications with the orbiter.

幾個小時後，又出了一件讓人擔憂的事情：着陸器與軌道飛行器重新建立通信聯繫時晚了約10分鐘。

Mission managers could not do anything; the readings they saw on their computer screens reflected what had occurred 28 minutes earlier — the time it took a radio signal to travel the 316 million miles from Rosetta to Earth.

負責人們沒辦法，只能等着；他們在電腦屏幕上看到的讀數，是28分鐘之前發出的——無線電信號從3.16億英里之外的”羅塞塔”傳輸到地球需要28分鐘。

But soon they received photos — a blurry image of Rosetta’s solar array taken by Philae about 50 seconds after separation, and then a sharper image by Rosetta of the descending Philae.

但很快，他們收到圖像——“羅塞塔”的太陽能電池陣列的模糊圖像，“菲萊”在分離約50秒後，把它拍了下來；然後收到了更清晰的圖像，是“羅塞塔”拍攝的“菲萊”正在降落的場面。

“We see the lander going down on the right track,” said Andrea Accomazzo, the flight director.

“我們看到着陸器在正確的軌道上降落，”此次飛行的負責人安德烈·埃克馬索(Andrea Accomazzo)說。

For now, Philae is working, and the instruments have already sent back some images and data. But if it is not anchored, Philae may not operate as long as hoped — the original goal was next March — as emissions of dust and gas grow as the comet moves nearer to the sun.

目前，”菲萊”正在工作，儀器已經發回了一些圖像和數據。但是，如果沒有抓牢彗星表面，“菲萊”的工作時間可能比預期的短——原計劃它會工作到明年3月——因爲彗星更加靠近太陽時，灰塵和氣體會揮發。

Even if the lander cannot complete the full mission, managers have said, Rosetta will still be a resounding success. Planetary scientists have never looked at a comet so close up for so long.

負責人說，即使這個着陸器無法完成全部任務，“羅塞塔”也仍是一個巨大成功。行星科學家們從未如此近距離地觀看一顆彗星如此之久。