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家园 这个有趣:中国击落其卫星有外交意义 by James Oberg

中国击落其卫星带有军事和外交意义 by James Oberg

http://www.wforum.com/newspool/articles/headline/93701.html

Bold move escalates space war debate

大胆举动引发太空战争论

China’s satellite shootdown has military, diplomatic implications

中国击落其卫星带有军事和外交意义

Analysis

By

NBC News space analyst

Special to MSNBC

Updated: 3:53 p.m. PT Jan 18, 2007

分析James Oberg

One week ago, a major “space first” occurred high over west central China — and in total darkness. No fiery explosion or glowing clouds would have been seen. But an aging Chinese satellite was instantaneously converted into a 542-mile-high cloud of metallic confetti.

一星期前,中国西部诞生了一项太空第一,但却不为人知。没有烈焰,没有火云,但在542英里高空一颗中国旧卫星突然粉碎成一片金属云。

As first reported in Aviation Week and Space Technology, and confirmed a few hours later by National Security Council spokesman Gordon Johndroe, U.S. intelligence agencies believe that China launched a medium-range military missile from its Xichang spaceport and guided it into a high-speed, head-on collision with a weather satellite called Fengyun-1C.

航空周刊首先报道的消息随后被国家安全理事会发言人证实。美国情报机构相信中国从西昌发射的精确制导的中程导弹高速迎头击中了风云一号气象卫星。For the first known time in history, a missile launched from the ground destroyed an orbiting satellite. The event is supposed to have occurred about 5:30 p.m. ET on Jan. 11, or 6:30 a.m. Beijing time Jan. 12.

这是历史上的第一次。地面发射的导弹摧毁了轨道卫星。这发生在美东时间一月11日下午5点30,北京时间12晨6点30分。

Previous anti-satellite weapons tests, conducted during the Cold War, involved either co-orbiting killer satellites (the Soviet approach) or an air-launched anti-satellite missile (the U.S. approach, also considered by the Soviets but never attempted). Some tests involved shooting ground-based anti-missile missiles toward satellites, but those missiles never hit their mark. And a NASA flub of a robot rendezvous in 2004 resulted in the active satellite accidentally hitting — but not damaging — its target satellite.

在此之前,美苏在冷战其间进行过反导试验。苏联用的是轨道杀手卫星。美国用的是在飞机上发射的导弹(苏联也想采取美国方式但从未尝试过)。也有些试验尝试从地面发射导弹,但他们从未击中过目标。到是2004年NASA发射的机器人与卫星会合时搞砸了,造成了一起主动碰撞事故。但被撞的卫星未受损伤。

Extraordinary chain of events

非凡的大事

Many of the details surrounding last week's event are classified — but even the unclassified information confirms that something extraordinary occurred.

很多细节仍属保密。但那些非秘密的讯息已证明了这件事非同小可。The North American Aerospace Defense Command, or NORAD, routinely releases reports on the orbits of hundreds of satellites of interest. Fengyun was the subject of about one or two reports per day throughout 2006, going into early January. But there were three reports on Jan. 10, then five reports on Jan. 11. And there have been no reports on Fengyun-1C since the time of the reported disintegration.

北美防空司令部NORAD定期报告数以百计卫星的轨道数据,包括每日一到两次 的风云卫星的数据,直到2006年至今年一月。但在10日,关于风云的报告有3份,11日有5份。然后就再也没有了。

上周卫星能量耗竭的流言开始传开。美国战略司令部的发言人表示并无此类消息,相反因为雷达正在跟踪数以百计的卫星残片,要到下周才能得到进一步的雷达反馈。

Evidence of an actual missile launch would require tracking data from infrared observation satellites operated by the Pentagon. While that information would be highly classified, the obvious confidence among officials promoting this interpretation implies that they do, in fact, possess that sort of evidence.

要证实导弹发射的确切消息,需要五角大楼旗下的红外观察卫星提供跟踪数据,尽管这种数据是绝密,卫星分析官员们的肯定态度已经暗示他们手上确实有这样的证据。It remains remotely

风云卫星仍然有很小的可能是自曝的。很多废弃的卫星和火箭会因为燃料泄漏混合而爆炸。但专家说这种可能性很小或几乎没有,因为卫星的唯一能源是内置电池,远没有那么大能量,所以内因可以排除。

Fengyun's loss also could be due to a massive meteoroid or orbital debris hit, occurring coincidentally within range of China’s main space launch base. But the odds of that are even smaller.

还有可能风云卫星是在中国基地发射导弹的同时被小行星或太空垃圾击中,但这种概率更小。

How big — and how high — a threat?

危险多大,多高?

Why Fengyun became such an object of interest to U.S. military intelligence agencies in the days before the missile launch remains intriguing — and possibly of critical importance. Perhaps the retired satellite had been reactivated, and observers recognized this as an omen of the impending fireworks.

风云卫星为何实现九位美国军情机构关注,这是耐人寻味甚至极其重要的。可能这颗废弃的卫星突然被激活,在有心人眼中预示着这场焰火表演的来临。

.

NORAD最后发布的轨道数据表明卫星轨道的远端被提升了20英里/32公里。这是当卫星准备与地面来客会面的典型表现。国际太空站在与俄国飞船对接时也是如此。

In fact, the reason the U.S. Air Force chose the air-launched anti-satellite system is that it does not have to have its target line up with a ground-based missile pad. Naturally, a real target in the real world would never make such a helpful maneuver.

事实上这也是美国选择空基反卫星武器的原因:目标卫星轨道不需要被改变。当然,真正的目标是决不会配合你而做这样的机动的。

如果目标不作如此机动,而让它容易被击中的话,地面攻击将很可能从侧面飞来。几何规律使这种攻击最后的角度变大,从而更不容易导引。这可以做到,但不那么可靠。

The geometry of this particular test (and also, whether this test was the first shot, or the fourth or fifth or more) remains classified. But further leaks and revelations can be expected.

这次测试的弹道(不管是第一次就击中还是第4次5次)是保密的。但我们期望能有更多的消息。

How to avoid a space bullet

怎样避免太空子弹

Also to be expected are suggested schemes for countermeasures. First of all, space is not under a uniform hazard from ground-based weapons. The higher you are, the less threatened you are. This is partly a matter of travel time: It could take a weapon four to six hours to reach a target in the 24-hour geosynchronous arc over the equator, where critical observation and applications satellites are located. But it's also a matter of accuracy and closing speed. Higher orbits pose much more of a challenge for weapons that depend on a fast relative closing speed for a “kill.”

也来谈谈反制措施。首先,太空各处受到地基武器的威胁程度并不相同。你越高就越安全。这跟旅行时间有关。一件武器需要飞行4-6小时才能攻击同步轨道上的目标,重要的观察卫星部署在那里。精度和接近速度也很重要。要攻击高轨道的目标,对武器的速度就会提出更高的挑战。

In lower orbits, the best defense is a good pretense. That is, a potential target may survive by not allowing its hunters to know where it is accurately enough to get a warhead on a collision course. Either the target follows an adequately unpredictable orbit (often only a matter of being a few miles away from where the killer expects it to be), or it is accompanied by decoys in nearby orbits.

在低轨,最好的防守是隐藏。可能的目标通过不让敌人知道位置,从而达不到命中精度来存活。目标可以采取多变难测的轨道,或有诱饵掩护的方法躲过攻击。Deploying a larger number of smaller satellites is also an option. Being able to launch replacement satellites quickly has been considered, but producing and stockpiling enough spare payloads and boosters — and then getting the payload activated quickly enough once it arrives in space — has proven to be an operational and engineering nightmare.

布置为数众多的小卫星也是一个选择。人们也考虑过快速发射备份卫星,但生产足够的备件,然后立刻发射到太空并使用—这绝对是工程和操作上的噩梦。

The last-ditch defense — actually trying to stop an incoming impactor — remains a science-fiction dream. And that is largely because the “kill mechanism” of the weapon is so very, very simple.

最后一道防线—阻止袭来的弹头—仍然是科幻小说中的梦想。这主要是因为这种武器的“杀伤机制”非常简单。

It’s a throwback to the first weapons our remote ancestors used on the African savannah: Hit the sucker with a rock.

这是一次大倒退,就像我们在南非大草原的远祖用的第一件武器:用石头扔那些王八蛋吧

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