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93 votes
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Why does it take so long to develop modern military jets?

First of all, it took at least five years even back then, but your observation is absolutely correct. You would need to go back one more decade to find a frontline fighter that was designed within ...
88 votes

Why does it take so long to develop modern military jets?

There are quite a few reasons for this- technically speaking, the primary one is that the system complexity has increased tremendously. More systems mean more interfaces, more redundancies, meaning ...
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65 votes
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Why was the production of the Lockheed SR-71 Blackbird halted?

Why did they stop building it? Because they built 32, and that was as many as was needed at the time. 32 spy planes was plenty for the USAF/CIA to use, so building more would have been a waste. By ...
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65 votes
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How did SR-71 spy, flying at 80,000 ft and 3500 km/h?

The SR-71 Blackbird was equipped with specialized cameras. It would overfly the area of interest and take high-resolution pictures of the ground. Of particular interest is the Technical Objective ...
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45 votes

Why does the SR-71 Blackbird sometimes have dents in the nose?

The SR-71 had a detachable nose (photo #2), and could change between three different nose cones depending on the mission. I haven't found a lot of information on the three, other than what this site ...
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43 votes

Why does it take so long to develop modern military jets?

UPDATE: I want to clarify/emphasize a few things in my answer. #1: Ultimately, the core driver of development time is growing complexity. More advanced threats means more advanced systems, which ...
41 votes
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Could the SR-71 Blackbird be used for nearspace tourism?

Significant issues with the concept: the SR-71 lacks RCS, so you'd lose attitude control if you got significantly above normal operating height. I originally wrote that it doesn't handle in-flight ...
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36 votes
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Could a SR-71 be shot down today?

Could SR-71 be shot down today? Theoretically yes. Modern day SAMs like the 40N6 that travel at speeds of Mach 6 can intercept an SR 71 within an operational range of 250 miles upto an altitude of 18 ...
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35 votes
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Why did the SR-71 Blackbird have a light on its top?

That is an anti-collision light as described in the flight manual: Anti-Collision/Fuselage Lights and Switch Two combination retractable anti-collision and fuselage lights are located at the top and ...
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33 votes
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How do fast-flying aircraft avoid overheating?

To avoid overheating, the usual trick is to select the right material: The Concorde used a special aluminium alloy, called Hiduminium, which had higher strength at elevated temperatures and allowed ...
32 votes
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SR-71 flew 2193 mph. How can this mathematically be Mach 3.3?

The SR-71 was only capable of Mach 3.3 flight at altitude. You can see the limitations in the pilot's operating handbook(POH) for the aircraft: At higher altitudes the relative speed of sound is ...
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30 votes

How did SR-71 spy, flying at 80,000 ft and 3500 km/h?

This is the section of the original SR-71 operation manual that describes in detail how the camera works. The plane was equipped with an Optical Bar Camera "The Optical Bar Camera (OBC) is a high ...
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24 votes

Did the SR-71 have any windshields?

It did! You can see a bit of it here or in the reflection here And here it is from the exterior
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22 votes
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Did the SR-71 have any windshields?

There are forward-facing windows in the SR-71. The image you posted is just of the instrument panel. The windows are better visible in the photo below. This is from a simulator but gives a better idea ...
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22 votes

Could the SR-71 Blackbird be used for nearspace tourism?

I work and have worked with several SR-71 crew members. In the past, they have pointed out two principle impediments: Crew workload Cost Crew workload is shared between both crewmembers, and the ...
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21 votes
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How long did the SR-71 take to get to cruising altitude?

According to the performance data in the manual it takes 19.9 minutes to get to 70,600 feet. Refueling time will depend on how much fuel is needed for the mission as well as how long it takes to ...
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21 votes

Why did the SR-71 Blackbird have a light on its top?

During missions the SR-71 had to be refuelled air to air many times. These missions took place also at night, so visual cues were absolutely necessary. Also the mission obviously were often flown ...
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19 votes

What is a ramjet?

A jet engine compresses air, heats it by mixing it with fuel and burns it, and lets the heated air escape at the end, where it accelerates to more than its initial speed in a convergent-divergent ...
19 votes

What is the minimum turning radius of an SR-71?

The Turn Radius of the SR-71 would depend on its speed. The faster it went the wider its turn radius was. The SR-71 had a minimum turning radius at altitude of about 80 nautical miles (NM) . It was ...
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19 votes
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What are the limiting factors for high altitude planes (e.g: U2 or SR71) preventing them from going higher?

The limiting factor for subsonic aircraft, including the U-2, is well explained here. For supersonic aircraft this answer simply says the limit is "a combination of wing loading and maximum speed". ...
17 votes

Why does it take so long to develop modern military jets?

In the age of computerized design, drafting, testing and milling, we can develop products faster than ever before. It's definitely not technology slowing down development. When we develop a plane for ...
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16 votes
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Why does the J58 engine of the SR-71 have a diffuser after the inlet spike?

Generally, a compressor cannot work efficiently at supersonic speed due to the shockwaves, the role of the inlet cone and diffuser is to slow the air below Mach 1. There is a similar need for a ramjet,...
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15 votes
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Why was the U-2 so different from the SR-71?

Because the requirements were different. When U-2 was developed, the requirement was for an aircraft which would fly high at 70,000' due to the (mistaken) belief that the Soviets would be able to ...
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15 votes

Why does it take so long to develop modern military jets?

This is just an additional point, but a bit more than a comment. In the late 60s there was still a cohort of design/test personnel whose skills and attitudes were formed during WWII and the early ...
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15 votes

Could the SR-71 Blackbird be used for nearspace tourism?

Typical SR-71 missions proceeded as follows: Fill tanks on ground. Tanks leaking fuel like crazy, by design. Plane takes off, with fuel leaking everywhere. Plane gets to altitude, and flies very fast ...
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13 votes
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What is the minimum turning radius of an SR-71?

Please use the equations of this answer. The numbers might be different, but the physics are the same. EDIT: Thanks to D_S for providing the link to the manual. When flown with the maximum allowable ...
13 votes

Why was the production of the Lockheed SR-71 Blackbird halted?

For several reasons: First off, the SR-71 was a plane which was never intended. An earlier Blackbird incarnation, the single seat A-12 had been in service for several years with the CIA under the ...
13 votes
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What advantages would a triangular shaped spy plane have over a an SR-71?

The 'triangle' wing design that you refer to is pretty common. It is called the delta wing design and is used in a number of high speed aircraft, for example, the North American XB70 Valkyrie. In ...
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12 votes
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Can stainless steel replace titanium for Mach 3+ speeds?

Both the MiG-25 and MiG-31 designs had engines that would overheat and be damaged an anything past Mach 2.83, so both planes were limited by this. Typical speeds were closer to Mach 2.5 to extend the ...
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