The idea of inflatable spacecraft is not new. The Echo I - NASA's first communication satellite - was essentially 100-foot-wide Mylar balloon that reflected radio transmissions from the ground.

充气式航天器并不是什么新颖的想法，NASA的第一颗通讯卫星回声1号实际上就是一个宽30米的聚酯薄膜大气球，它是用来发射来自地面的无线电广播的。

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We use … used it to track potentially dangerous asteroids, sending out a strong pulse of radio waves and listening for the echo.

我们通常…通常用它来跟踪有潜在危险的小天体，发出强大的无线电脉冲然后聆听回波。

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Timing an echo of radio waves is the principle on which radar operates.

计算无线电波 回声的时间乃是雷达运行所依据的原理。

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Moscow Echo radio says a case of suspected criminal neglect has been opened.

BBC: Russian army officer sacked after pneumonia deaths

They simulated stray radio tower signals in UL's echo-free chamber (pictured here)outside Chicago to make sure the signals wouldn't accidentally trigger a car's air bag.

FORBES: By the Numbers

The sing-along choruses of "She's Already Gone" and "Mercy" echo Oasis, proving to be highly catchy, radio-ready rock, though the Shys stand as a grittier, gutsier version.

NPR: The Shys: 'The Hangman'