7-12 美国航空航天局成功试飞超高音速喷气机（在线收听）

NASA Successfully Tests Hypersonic¹ Jet

Three years after its first test flight ended in an explosion, NASA on March 27 successfully launched an experimental jet that the agency believes reached a record-setting speed of about 5,000 mph.

The unpiloted X-43A made an 11-second rocket boosted flight, then went through some twists and turns during a six-minute glide before plunging into the Pacific Ocean about 400 miles off the California coast.

Flight engineer Lawrence Huebner said preliminary data indicated the needle-nosed jet reached a maximum speed of slightly over seven times the speed of sound, or about 5,000 mph, after a rocket boosted it to about 3,500 mph. Huebner said it was the first time an “ air-breathing” jet had ever traveled so fast. The rocket powered X-15 reached Mach² 6.7 in 1967.

NASA built the X-43A under a ＄ 250 million program to develop and test an exotic type of engine called a supersonic-combustion³ ramjet⁴, or scramjet. In theory, the air-breathing engine could propel an airplane to speeds of Mach 7 or faster, enabling around-the-world flights that would take several hours. The Department of Defense also is working on the technology, which is eyeing for use in bombers that quickly could reach targets anywhere on the globe.

A third X-43A could fly as early as the fall.

注释：

1. hypersonic [7haipE(:)5sCnik] a.  超高音速的(指超过音速5倍以上的)

2. Mach [mB:k] (number) n.  马赫(数)，表示物体在介质(如空气)中的移动速度与音速之比，因此Mach6.7相当于音速的6.7倍

3. combustion [kEm5bQstFEn] n.  燃烧

4. ramjet [5rAmdVet] (engine) [空] 冲压式喷气发动机

美国航空航天局成功试飞超高音速喷气机

3月27日，美国航空航天局成功发射了一架试验喷气机，该机构认为该机的时速达到了创纪录的5000英里左右。这是美国航空航天局在3年前首次试飞以爆炸结束后的再度尝试。

这一型号为X43A的无人驾驶飞机在11秒的火箭助推飞行之后，进行了6分钟的滑翔，并伴随着一些曲线前进和转弯动作，最后在距加利福尼亚海岸约400英里的太平洋海域溅落。

飞行工程师劳伦斯·许布纳说，初步数据显示，在火箭将其时速推进到大约3500英里之后，这一鼻端呈针状的喷气机的极速稍稍超过了7倍音速，或者说达到了5000英里/小时左右。许布纳说，这是采用“喷气”技术的喷气机首次达到如此高的速度。1967年，以火箭为推进动力的X15曾达到6.7马赫。

美国航空航天局为建造X43A耗资2.5亿美元，用于开发和测试一种新型的引擎，叫做超音速燃烧冲压式喷气引擎(简称scramjet)。从理论上讲，这种喷气引擎可以将飞机速度推进到7马赫甚至更快，使飞机能在数小时内完成环球飞行。目前，美国国防部也在研究这一技术，目的是研制出能迅速抵达全球任何地点的轰炸机。

第三架X43A最早可望在今年秋季试飞。