美国海军将停止开发一种旨在以高达7倍音速发射弹丸的高科技武器。
The Navy spent more than 10 years developing the weapon, called an electromagnetic railgun. The cannon-like railgun uses electricity instead of chemical substances to fire projectiles.
美国海军花了10多年时间开发这种名为电磁轨道炮的武器。这种类似大炮的轨道炮利用电能而不是化学物质来发射弹丸。
A report released earlier this year by the Congressional Research Service stated that the Navy had been developing the railgun as a firing weapon to support U.S. Marines operations. The report said the development also centered on possible use of the railgun as a missile defense system.
美国国会研究服务处今年早些时候发布的一份报告称，海军一直在开发轨道炮作为一种支持美国海军陆战队行动的射击武器。该报告称，开发还集中于将轨道炮作为导弹防御的潜在用途。
The move to cancel railgun development comes as the U.S. Department of Defense turns its attention to the development of hypersonic missiles, The Associated Press reports.
据美联社报道，取消轨道炮开发的举措发生在美国国防部将注意力转向高超音速导弹的开发之际。
Hypersonic is a term that relates to speeds of more than five times the speed of sound, also known as Mach 5. In addition to flying at extremely high speeds, hypersonic weapons are designed to move in ways that make them difficult to find and destroy in flight.
高超音速是跟超5倍音速的速度相关的一个术语，这个速度也被称为5马赫。除了以极高速度飞行以外，高超音速武器被设计成在飞行中以一种很难被发现和摧毁的方式运动。
The U.S. military has been putting money into the development of hypersonic weapons in recent years in an effort to keep up with hypersonic military programs in China and Russia.
近年来美国军方一直在投入资金开发高超音速武器，以追赶中俄两国的高超音速军事项目。
Matthew Caris is a defense expert with the private advisory company Avascent Group. He told the AP that "the railgun is, for the moment, dead."
马修·卡里斯是私人咨询公司Avascent Group的国防专家。他对美联社表示：“轨道炮目前已经完蛋了。”
The halt in railgun development, Caris said, suggests that the Navy saw difficulties in implementing the technology. In addition, the Navy likely recognized that hypersonic missiles have higher performing abilities than the railgun, he added.
卡利斯表示，轨道炮开发的停止表明美国海军看到了在实现这项技术方面存在的困难。他还表示，此外海军可能认识到高超音速导弹比轨道炮具备更高性能。
Lieutenant Courtney Callaghan is a Navy spokesperson. She told the AP that the Navy's decision will free up resources for hypersonic missiles, as well as lasers and other electronic warfare systems.
考特尼·卡拉汉中尉是海军发言人。她对美联社表示，海军的这项决定将为高超音速导弹、激光以及其它电子战系统腾出资源。
The Navy spent about $500 million on research and development of the railgun, said Bryan Clark, a defense expert at the Hudson Institute.
哈德逊研究所的国防专家布莱恩·克拉克表示，海军在轨道炮的研发上花费了大约5亿美元。
The railgun held the possibility of providing an effective weapon at a much lower cost than smart bombs and missiles. Using electricity, a railgun can fire a projectile at six or seven times the speed of sound, creating enough energy to destroy targets.
轨道炮仍有可能用比智能炸弹和导弹便宜很多的价格提供一种有效武器。轨道炮利用电能可以以6到7倍音速发射弹丸，产生足够大能量来摧毁目标。
But Clark said the program experienced a number of problems, including the limited range of the railgun in testing. In addition, its usefulness for missile defense was also limited by range and rate of fire, Clark added.
但是克拉克表示，该项目遇到了许多问题，包括轨道炮在测试中的有限射程。克拉克还表示，此外它在导弹防御方面的可用性也受到了射程和射速的限制。
Another big question was whether the gun could stay together during continuous firing, said defense analyst Norman Friedman.
国防分析师诺曼·弗里德曼表示，另一个大问题是这种大炮在连续射击时是否可以保持完好。
A normal gun can be fired about 600 times before the barrel has to be refurbished. But the barrel on tested railguns, Clark said, had to be replaced after about 12 to 24 shots were fired.
普通大炮在炮管必须整修前可以发射大约600次。克拉克表示，但是已测试轨道炮的炮管在发射大约12到24发后就必须更换。
A few years ago, the Navy was talking about putting the gun on the future USS Lyndon B. Johnson, the last of three stealthy destroyers. But now, the Navy is developing what it calls a "hypervelocity projectile," which is designed to be fired from existing gun systems.
几年前，美国海军还在讨论将轨道炮安装在未来的林登·约翰逊号驱逐舰上，这是3艘隐形驱逐舰中的最后一艘。但是现在，海军正在开发一种旨在从现有火炮系统发射的所谓高超音速弹丸，
I'm Bryan Lynn.
我是布莱恩·林恩。(51VOA.COM原创翻译，请勿转载，违者必究！)