Return of SR-71.

 

NASA plans to return the SR-71 to flight. The SR-71 is one of the fastest aircraft in the world. Its speed is Mach 3,3. But there are rumors. That. The new engines allow the SR-71 to accelerate to Mach 4. That will be hard to make in real life. Using the original twin-engine concept. The titanium body is also under heavy stress. When an aircraft travels at speeds over Mach 3. The SR-71 is the highest-flying regular aircraft. The reason for that is this. The aircraft makes a pressure wave. That wave pushes air into the engine compressor. This means its engines get more air. 

And that allows it to reach very high altitudes. The SR-71 was retired. by NASA in 1999. USAF removed its own SR-71 in 1990. Officially, the reason for that was high operating costs. But the USAF was probably afraid that the SR-71 accident could help the Russians create their own version of the system. 

The SR-72 “Dark Star” is a concept. That. It can be the successor of the SR-71. 

There are rumors about the “Aurora”. A mysterious prototype. That should be the successor to the SR-71. But there is no evidence that the “Aurora” actually existed. Or. Maybe there could be some individual prototypes. But the fact is this. 

"Nord 1500 Griffon II, which was powered by a turbojet–ramjet combination, a precursor to later turborocket designs. "(Wikipedia, Air turborocket)

Simple ramjet operation, with Mach numbers of flow shown (Wikipedia, Ramjet) 

“The air turboramjet engine is a combined cycle engine that merges aspects of turbojet and ramjet engines. The turboramjet is a hybrid engine that essentially consists of a turbojet mounted inside a ramjet. The turbojet core is mounted inside a duct. That contains a combustion chamber downstream of the turbojet nozzle. The turboramjet can be run in turbojet mode at takeoff and during low-speed flight but then switch to ramjet mode to accelerate to high Mach numbers.”  (Wikipedia, Ramjet) 

“Original schematic of a turboramjet design” (Wikipedia, Air turborocket) 

“Recreated schematic of an air turboramjet. Featuring: 1. compressor, 2. gearbox, 3. hydrogen and oxygen lines, 4. gas generator, 5. turbine, 6. ram burner fuel injector, 7. main combustor, 8. nozzle”(Wikipedia, Air turborocket) 

 

Diagram of the principle of operation of a scramjet engine. (Wikipedia, Scramjet)

Artist’s impression of SR-72. 

The SR-71 requires different types of engines for Mach 4+ operations. The SR-71 uses almost conventional turbojet technology. The system operates near its limits. When. The airflow runs too fast. It. Causes a situation. There, the fire falls out of the combustion chamber. The ramjet engine is the tool. That helps the aircraft reach Mach 6. 

The system requires ramjet engines. Outside. The jet engines. The aircraft accelerates to Mach 1+. Then it can start the ramjet engine. The ramjet is needed because the turbojet cannot work at very high speeds. The ramjet and scramjet engines require another concept. They require staged acceleration. The ramjet system accelerates the aircraft to Mach 7-8; there, the aircraft can start fuel injection into the scramjet. Those systems could be made. But they require new concepts. 

If reseachers. Want to create an air-breathing engine system. That allows aircraft to reach Mach 12+. They need a scramjet engine. The answer. It. Can be the rocket-ramjet or scramjet. When aircraft must accelerate to speed. Mach 7- 8. A scramjet is required. The system transports a fuel-oxygen mixture from the sides to the combustion chamber. The system has a flap or iris that closes the air inlet. When. The speed accelerates to the speed that the scramjet requires. For. Its ignition. The engine opens the iris. And. It lets air flow. To travel inside the engine. If a Mach 10- 20 traveling aircraft is really possible. 

That kind of system can be the tool that makes it operate. The aircraft can be a fundamental shuttle concept. It can travel in the upper atmosphere and low Earth orbit. 


https://www.twz.com/air/a-sr-71-blackbird-has-vanished

https://www.twz.com/air/could-nasas-sr-71-blackbird-be-modified-to-reach-mach-4

https://en.wikipedia.org/wiki/Airbreathing_jet_engine

https://en.wikipedia.org/wiki/Air_turborocket

https://en.wikipedia.org/wiki/Lockheed_Martin_SR-72

https://en.wikipedia.org/wiki/Ramjet

https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird