美国着手打造新一代无人侦察机sr-凯发k8官网

 

the unmanned sr-72 will use an engine that combines a turbine and a ramjet（冲压式喷气发动机） to reach its top speed of mach 6 - about 3,600mph (5,800km/h).

 

like its ¹, the sr-72 will be designed for high-altitude surveillance but might also be fitted with weapons to strike targets.

 

lockheed said the aircraft should be operational by 2030.

 

 

the sr-72 is being developed at lockheed martin's ² works r&d centre in california that designed and built the original blackbird.

 

that aircraft first flew in 1964 and was a mainstay of us air force spying and surveillance work until 1998. it typically flew at altitudes of 24,000m (80,000ft) and could reach speeds of mach 3.

 

in a blogpost about the sr-72, lockheed martin said the aircraft would operate at similar altitudes but would fly far faster. at mach 6 the plane could travel the 3,500 miles (5,500km) from new york to london in less than an hour.

 

while spy satellites can photograph enemy territory, the ³ long time it takes for them to be moved to a new orbit so they pass over a target can limit their usefulness.

 

by contrast, wrote lockheed martin, the sr-72 "would be so fast, an ⁴ would have no time to react or hide".

 

for the sr-72, lockheed martin is drawing on work done on the ⁵ htv-2 hypersonic technology vehicle. this is a test-bed for the futuristic technologies needed to support safe hypersonic flight and cope with the extreme conditions encountered by any object flying at such a speed.

 

for instance, on one test flight of the htv-2, the aircraft hit a top speed of mach 20 and its flight surfaces reached 1,927c (3,500f).

 

to reach mach 6, the sr-72 will use an engine that acts like a normal jet turbine until speeds of mach 3 are reached but which then operates like a ramjet to accelerate beyond that.

 

"speed is the next aviation ⁶ to counter emerging threats in the next several decades," said brad leland, lockheed martin's hypersonic programme manager on the blog. "the technology would be a game-changer in theatre, similar to how stealth（秘密，鬼祟） is changing the battlespace today."

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