Because of the temperature limitations of all material systems, cooling of engine components is required, as shown in Fig. 12.22. These extremely high temperatures pose significant material and structural challenges. It might take a bit longer-and you won’t be able to float around the cabin while in space-but you also won’t be throwing up on the way back down.The temperatures encountered in engine components (eg, inlet, combustor, and nozzle) are significantly higher than in the other structural components, as shown in Fig. 12.21. But a hypersonic aircraft will be so smooth and fast during all phases of flight that it could effectively glide unpowered for the final 500 miles of each trip. Indeed, rocket re-entries into the atmosphere are notoriously brutal experiences, given that the vehicles have to use steep descent angles and blunt shaping, as opposed to the sleek pointy-nose look of a hypersonic jet, to generate enough drag to slow down enough for landing. “The overall safety risk is much higher in a rocket while the passenger comfort level is much lower.” Rockets will never be as reliable as airplanes, for one thing, and they are scary and uncomfortable. Though rocket-powered spaceships are certainly exciting, Bowcutt thinks that air-breathing vehicles-meaning, those that ingest oxygen from the atmosphere for combustion rather than carrying it along with them in liquid form-have much greater potential. Both SpaceX’s Elon Musk and Virgin Galactic’s Richard Branson have indicated that they want to adapt their rockets for global flights, reaching from New York to Sydney, for instance, in just an hour. Hypersonic jets could also stack up favorably against vehicles in the other end of the spectrum: suborbital rockets. (The speed of sound at 35,000 feet is 660 mph the average jetliner cruises at 575 mph at the same altitude the fastest currently proposed supersonic jet would travel at Mach 2.2 at 50,000 feet, or 1,450 mph, and the rest hover around Mach 1 or 1.2.) They also tend to be smaller, which means they may not be able to carry much fuel and thus may have shorter ranges than airlines might like. Those airplanes actually only go a bit faster than commercial aircraft-even though they break the sound barrier in the process. This concept does, however, have advantages over other long range, high speed transportation visions, most notably the proposed next generation of supersonic jets.
A lot will have to go right for the effort to succeed, and such an aircraft would need to arrive with substantial proof of reasonable cost, safety, and efficiency in order for airlines and the military to want to actually fly it. (A merely supersonic aircraft flying between Mach 1 and Mach 2 would take an hour or two longer.)īoeing says a production aircraft with these capabilities-including autonomous piloting, as that technology continues to evolve-could be ready in 20 to 30 years, though a prototype could be ready in as soon as 5 or 10. The craft would travel at up to Mach 5, enabling it to cross the Atlantic Ocean in just two hours and the Pacific in three. Both visually and technologically, the airplane, which could be used for both military and commercial purposes, has much in common with an unmanned hypersonic surveillance and reconnaissance concept the company revealed in January.īoth share the general delta-wing configuration with dual rear fins, a streamlined fuselage, and a sharp nose. The company revealed renderings of its proposed hypersonic, passenger-carrying airliner Tuesday at the annual American Institute of Aeronautics and Astronautics conference in Atlanta. At least, if the airplane concept Boeing unveiled this week becomes reality. Aviation enthusiasts yearning for ultra-fast, ultra-sleek intercontinental transportation-rather than 18-hour flights on stuffed-to-the gills widebody behemoths-might finally get their wish.
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