BE-4 compilation
https://youtu.be/Nyn2gOimRfM=====
https://arstechnica.com/science/2016/03/behind-the-curtain-ars-goes-inside-blue-origins-secretive-rocket-factory/Propulsion
Much of Blue Origin’s factory has been given over to development of the Blue Engine-4, or BE-4. I suspect that's why Bezos finally allowed a handful of reporters into the inner sanctum of his rocket business. Blue Origin is competing with a traditional aerospace company, Aerojet Rocketdyne, to build the engines for a new rocket, the Vulcan. And this isn't just any rocket. It will become the flagship vehicle for the United Launch Alliance (ULA), which delivers most of US national security payloads to space.
ULA’s existing workhorse rocket, the Atlas V, has performed flawlessly for more than 60 launches. But it has also become an increasingly controversial launch vehicle because it is powered by Russian RD-180 engines. As US-Russia relations have soured, Congress has demanded that ULA end its dependence on the RD-180.
Blue Origin unquestionably leads in the race to power the new Vulcan rocket under development, but as a traditional aerospace contractor, Aerojet Rocketdyne has well-connected friends in Congress. Blue Origin, with an investment from ULA, has privately developed the BE-4 engine, whereas Aerojet just was promised more than $500 million from the federal government to design and build its AR1 engine.
Bezos invited us here because he wants the world to know his engine is better, it was developed with private money, and it will be ready several years sooner than the publicly subsidized Aerojet engine. “If ULA has to go with the AR1 engine, that will lead to a significant delay,” Bezos said. “That is going to dramatically increase the gap where we have to rely on Russian engines because we started four years ago and there’s no rushing it.”
There are two main components of a rocket engine: the thrust chamber, where combustion takes place and is thrust backward out of a nozzle, and a large pumping system to take propellants from the fuel tank and bring them up to a high pressure. “In principle, rocket engines are simple, but that’s the last place rocket engines are ever simple,” Bezos said.
Blue Origin hopes to conduct its first full-scale firing test of the BE-4 engine by year’s end. At 550,000 pounds of thrust, the new engine is five times more powerful than the BE-3 engine used in Blue Origin’s New Shepard vehicle, which will perform suborbital flights. Like the smaller BE-3 upon which it is modeled, a main feature of the BE-4 is its reusability, and it’s being designed to fly a minimum of 25 missions.
Bezos explained his philosophy on how to build a successful reusable engine: “Our strategy is we like to choose a medium-performing version of a high-performance architecture.” Here’s what that means: The Russian RD-180 engine is a high-performing version of a high performance architecture. It uses the best materials and pushes the performance envelope. It is the Ferrari of engines. But that comes with a cost. When it fires, the RD-180 engines produces extremely high chamber pressures of up to 3,700 psi. By comparison, the BE-4 engine produces a chamber pressure of 1,950 psi.
Developing an elite engine like the RD-180 was a decade-plus project, on par in complexity to the space shuttle’s main engines. It required expensive materials. On the plus side, this provides a lower weight engine and a higher thrust-to-weight ratio. But the engine’s specific impulse isn’t all that much greater than the BE-4, which can be built more easily, and because it doesn't push performance limits can be reused.
This isn’t just theory. Blue Origin validated this philosophy in January. Last November, after it successfully flew and landed its New Shepard rocket powered by a single BE-3 engine, it refurbished the vehicle at a cost “in the small tens of thousands of dollars,” Bezos said. His technicians never even removed the engine from the vehicle. “We inspected it and said, let’s go. It was designed to be reusable from the start.” And so it flew again.
< Edited >
