中國發射全球首顆量子通訊衛星墨子號

BEIJING — China launched the world’s first quantum communications satellite from the Gobi Desert early Tuesday, a major step in the country’s bid to be at the forefront of quantum research, which could lead to new, completely secure methods of transmitting information.

北京——週二凌晨，中國從戈壁灘發射升空了全球首顆量子通訊衛星。這是中國為爭取站在量子研究最前沿而邁出的重要一步。量子研究可能會帶來新的完全安全的資訊傳輸方式。

Researchers hope to use the satellite to beam communications from space to earth with quantum technology, which employs photons, or particles of light. That type of communication could prove to be the most secure in the world, invulnerable to hacking. Scientists and security experts in many countries are studying the technology.

研究人員希望，通過量子技術，用這顆衛星將資訊從太空傳輸到地球。量子技術會用到光子，也就是光的微粒。這種通訊方式可能會證明是全世界最安全、最不易受黑客攻擊的。很多國家的科學家和安全專家在研究這項技術。

The satellite is expected to circle the earth every 90 minutes after entering orbit at an altitude of about 310 miles, according to a report by Xinhua, the state news agency.

官方通訊社新華社的一篇報道稱，在進入距地面約500公里高的軌道後，這顆衛星預計每90分鐘繞地球一圈。

China’s many high-tech scientific endeavors, including its ambitious space program, have enormous backing from the central government. The country’s 13th Five-Year Plan, an economic blueprint that was announced in March, listed quantum technology as a focal point for research and development.

中國的很多高科技科研活動，包括其巨集大的太空計劃，得到了中央政府的大力支援。中國今年3月公佈的有關經濟發展藍圖的十三五規劃綱要將量子技術列為一個研發重點。

Traditional communications satellites send signals using radio waves. But a quantum communication satellite uses a crystal that produces a pair of entangled photons whose properties remain entwined even as one is transmitted over a large distance. Messages could be sent by manipulating these properties.

傳統的通訊衛星使用無線電波傳送訊號。量子通訊衛星用的則是一種結晶體，這種晶體會產生一對相互糾纏的光子。即便將其中一個傳輸到很遠之外，它們的屬性依然會糾纏在一起。可以通過控制這些屬性來發送資訊。

An article about the Chinese program published by the journal Nature in July said any tinkering with quantum communications would be detectable, which is why the method is secure. “Two parties can communicate secretly,” the article said, and could be “safe in the knowledge that any eavesdropping would leave its mark.”

今年7月，《自然》雜誌(Nature)發表了一篇文章，介紹中國這個專案。文中稱，對量子通訊做手腳的任何行為都會被發現，而這正是這種方式安全的原因。文章說，“雙方能夠祕密交流”，並且“有一種安全感，因為知道任何偷聽都會留下痕跡”。

If China succeeds in its satellite launch, the article said, that could mean many more such Chinese satellites in orbit, “which will together create a super-secure communications network, potentially linking people anywhere.”

文章表示，如果中國的衛星發射成功，可能意味著中國會把更多的這類衛星送上軌道，它們“合起來將構成一個超級安全的通訊網路，可能會將任何地方的人連線在一起”。

“But groups from Canada, Japan, Italy and Singapore also have plans for quantum space experiments,” the article said.

“但加拿大、日本、義大利和新加坡的團隊也有量子太空實驗計劃，”文章說。

While the communication would be unbreakable, the data transmission rate would also, at least at first, be glacial, more akin to the telegraph than the internet.

儘管這種通訊方式可能固若金湯，但資料傳輸速率起碼一開始會極慢，更像電報而非網際網路。

The Chinese researchers hope to use the satellite and quantum communications to establish secure transmissions between two ground sites. In theory, the satellite can provide the connection between them. The first major link in China would be between Beijing and Shanghai, and might open this year, according to Xinhua.

中國的研究人員希望利用這顆衛星和量子通訊，在地面上的兩個地點之間建立安全的資訊傳輸。理論上，它能夠提供兩地之間的聯絡。新華社稱，中國最先實現這種聯絡的可能是在北京和上海之間，或許會於今年開通。

The satellite, which weighs over 1,300 pounds, is called Quantum Experiments at Space Scale, or Quess, and nicknamed Micius, after a Chinese philosopher and scientist in the fifth century B.C.

這顆衛星逾重600公斤，名叫量子科學實驗衛星，英文縮寫為Quess，暱稱墨子號。這是為了紀念公元前五世紀的中國哲學家、科學家墨子。

Pan Jianwei, the chief scientist of the quantum satellite project, told Xinhua earlier that the overall project involved building four ground stations for quantum communication and one station in space for experimental quantum teleportation.

量子衛星專案的首席科學家潘建偉早前對新華社表示，整個專案涉及修建四座量子通訊地面站，一座空間量子隱形傳態實驗站。

A 2012 article in Nature said Mr. Pan was in his early 30s when, in 2001, he set up China’s first laboratory for manipulating the quantum properties of photons.

《自然》雜誌2012年發表的一篇文章稱，在2001年，30歲出頭的潘建偉建立了中國首個研究如何控制光子的量子屬性的實驗室。

“The lucky thing was that, in 2000, the economy of China started to grow, so the timing was suddenly right to do good science,” Nature quoted him as saying.

“幸運的是，2000年，中國的經濟開始起飛，因此進行高質量科學研究的時機突然到了，”《自然》雜誌當時援引他的話報道。