Bezos’ Blue Origin space venture, which he founded more than 16 years ago, is in the midst of building a next-generation rocket engine fueled by liquefied natural gas, known as the BE-4. Today, Bezos lifted the curtain on one of the engine’s subassemblies and highlighted how Blue Origin is using 3-D printing.
Here’s what he said in his email update:
“Robert Goddard’s first rockets used compressed gas to force the liquid propellants into the engine thrust chambers. While simple in design and a logical starting point, he quickly realized the limitations with this approach: it requires thick-walled heavy propellant tanks and limits the engine’s chamber pressure and performance, both of which limit payload capacity. The answer was turbopumps. Store the propellants in low-pressure light tanks, and then pump the propellants up to high pressure just ahead of injection into the main chamber.
“For even more performance, you can add one or more boost pumps ahead of the main pumps. We’ve done that on the oxidizer side of our BE-4 engine. Our Ox Boost Pump (OBP) design leverages 3-D additive manufacturing to make many of the key components. The housing is a single printed aluminum part and all of the stages of the hydraulic turbine are printed from Monel, a nickel alloy. This manufacturing approach allows the integration of complex internal flow passages in the housing that would be much more difficult to make using conventional methods. The turbine nozzles and rotors are also 3-D printed and require minimum machining to achieve the required fits.
“The OBP was first demonstrated last year in testing, where we validated its interaction with a main pump. The second iteration of the OBP for BE-4 is now in test. We’ve also just finished assembly of the unit that we’ll install for the first all-up BE-4 engine test.
“We’ll keep you posted on how our BE-4 powerpack and engine testing progresses.
The last part of the email may well be the most interesting part for space industry observers. The BE-4 engine is designed to power not only Blue Origin’s New Glenn orbital rocket, but United Launch Alliance’s next-gen Vulcan semi-reusable rocket as well.
ULA is on the brink of deciding whether to go ahead with the BE-4, or go to Plan B – the AR-1 engine that’s being offered as an alternative by Aerojet Rocketdyne. That decision will be based on the results from the all-up BE-4 engine test.
A year ago, ULA executives had hoped to get those results by the end of 2016. The test has now slipped into 2017, however. Today’s email suggests that the crucial all-up test is coming soon but not immediately – and that the Ox Boost Pump, at least, has undergone further refinement.
Meanwhile, Blue Origin is continuing with its suborbital test flight program for the New Shepard reusable spaceship, powered by a hydrogen-fueled BE-3 engine. Its first New Shepard was retired last year after making five successful spaceflights. Now New Shepard 2.0 is being readied for its first outing at Blue Origin’s launch test facility in West Texas.
If all goes well, test astronauts will be climbing aboard New Shepard for suborbital space tryouts by the end of this year, while the BE-4 engine will be ready to go into production at Blue Origin’s headquarters in Kent, Wash.
As Bezos says, we’ll keep you posted.