A Closer Look At Blue Origin’s BE-7 Engine
With the recent announcement of Blue Origin’s lunar lander selection, the company now has a lot of work ahead of it in preparation for this mission. While Blue Origin leads the National Team, the company’s primary contribution will be the lander portion which relies on the BE-7 engine.
For years now this engine has been going through development and testing. Recently we’ve seen a significant increase in production as the company pumps out these engines and their respective components. All in an effort to test BE-7 more frequently and make sure they have a robust and reliable engine ready for the initial test flights.
Unlike the BE-4 engine, the BE-7 is a lot smaller and less powerful, but this design makes it a viable option for the lunar surface and Moon operations. Here I will go more in-depth into the recent progress on this engine, production increases, what we can expect in the coming months, and more.
BE-7 Production
The BE-7 is an additively manufactured, high-performance, dual-expander cycle engine, generating 44.5 kN (10,000 lbf) thrust. Blue Origin is currently maturing the design, manufacturing hardware and have begun hotfiring the engine. As far as recent testing, just a few months ago in March the BE-7 team conducted a successful Thrust Chamber Assembly (TCA) test at NASA Marshall Space Flight Center Test Stand 116. This specific test on an upgraded TCA brought the engine’s cumulative test time to more than 4000 seconds.
In addition to testing, just over a month ago we got a host of new information on the production and engine manufacturing. Specifically on April 18th Blue Origin tweeted saying “Pictured here are nickel-based super alloy jackets that get vacuum-brazed onto the BE-7 slotted copper liner to complete the regen nozzle. The cone shape is hydraulically formed into the final nozzle contour using the tooling shown.” The company also showed off images of additively manufactured single piece BE-7 injectors where hydrogen and oxygen are injected into the main combustion chamber. They even showed off first and second stage fuel turbopump impellers for the BE-7 engine before final machining. Each BE-7 hydrogen pump uses two of these shrouded titanium impellers.
All of these parts are being created in mass as the company ramps up production. The recent lander selection only adds to this demand and need for testing. All the way back in 2020, Blue Origin completed the fourth thrust chamber test series of its BE-7 engine. During this test campaign, the thrust chamber was tested for a duration of 20 seconds. This brought the cumulative testing time on the BE-7 thrust chamber to 1,245 seconds. In the almost two years since then, they have added around 2,800 seconds of additional testing.
At the time the senior vice president of Engines at Blue Origin commented, “This thrust chamber test measured the ability to extract energy out of the hydrogen and oxygen cooled combustor segments that power the engine’s turbopumps – the key to achieving high engine performance. The high specific impulse, deep throttling, and restart capabilities of the BE-7 make it the ideal engine for large lunar payload transport as well as many other in-space applications” he said.
Blue Moon’s thrusters, fuel cell, and BE-7 main engine all use hydrogen and oxygen supplied from the primary flight tanks, creating a highly efficient integrated power and propulsion system. It’s important to point out however that Blue Origin still needs to complete a lot of testing. The company has three main engines, two of which have yet to be tested on an actual launch. The third that has, recently was the reason for the NS-23 mishap. In this case, they determined that a structural fatigue failure of the BE-3PM engine nozzle during powered flight caused the failure. The structural fatigue was caused by operational temperatures that exceeded the expected and analyzed values of the nozzle material.
The BE-4 has been performing well but it might be a while before we see it fly as Vulcan continues to run into small delays. At the same time each of these engines are very different and in the case of BE-7, isn’t even meant for use on Earth, but on the Moon. As more testing continues we will get a better idea of the reliability and performance of this hardware.
BE-7 Lunar Lander
As partially mentioned before NASA selected Blue Origin to develop a human landing system for the agency’s Artemis V mission to the Moon. In this case, Blue Origin will design, develop, test, and verify its Blue Moon lander to meet NASA’s human landing system requirements for recurring astronaut expeditions to the lunar surface, including docking with Gateway, a space station where crew transfer in lunar orbit. In addition to design and development work, the contract includes one uncrewed demonstration mission to the lunar surface before a crewed demo on the Artemis V mission in 2029. The total award value of the firm-fixed price contract is $3.4 billion.
This uncrewed demo will be one of the first real tests for this engine and the overall hardware. Brent Sherwood, vice president, Advanced Development Programs, Blue Origin pointed out that “The BE-7, a turbomachinery-based engine using the most efficient propellants, is optimal for deep-space maneuvers and landing on the Moon. Our engine test series is steadily maturing what’s needed to get Americans safely on the lunar surface as soon as possible. We are positioning to use the Moon’s ice resources for rocket propellant, which will make exploration sustainable and open the Moon for commerce.”
For the Artemis V mission, NASA’s SLS (Space Launch System) rocket will launch four astronauts to lunar orbit aboard the Orion spacecraft. Once Orion docks with Gateway, two astronauts will transfer to Blue Origin’s human landing system for about a weeklong trip to the Moon’s South Pole region where they will conduct science and exploration activities. Artemis V is at the intersection of demonstrating NASA’s initial lunar exploration capabilities and establishing the foundational systems to support recurring complex missions in lunar orbit and on the surface as part of the agency’s Moon to Mars exploration approach.
These vehicles are powered by LOX-LH2. The high-specific impulse of LOX-LH2 is intended to provide a dramatic advantage for high-energy deep space missions. Nevertheless, lower performing but more easily storable propellants (such as hydrazine and nitrogen tetroxide as used on the Apollo lunar landers) have been favored for these missions because of the problematic boil-off of LOX-LH2 during their long mission timelines. Through this contract, Blue Origin and its partners plan to move the state of the art forward by making high-performance LOX-LH2 a storable propellant combination. Under SLD, we will develop and fly solar-powered 20-degree Kelvin cryocoolers and the other technologies required to prevent LOX-LH2 boil-off. Future missions beyond the Moon, and enabling capabilities such as high-performance nuclear thermal propulsion, will benefit greatly from storable LH2. Blue Origin’s architecture also prepares for that future day when lunar ice can be used to manufacture LOX and LH2 propellants on the Moon.
This is the propellant combination of BE-7. Taking a closer look at the company’s Blue Moon lunar lander. You can see in animations and images that they plan to use a single BE-7 engine for the landing. This Blue Moon lander can deliver large infrastructure payloads with high accuracy to pre-position systems for future missions. The larger variant of Blue Moon has been designed to land an ascent vehicle, and is a part of the HLS National Team integrated system chosen by NASA to return humans to the Moon. In total, Blue Moon can land multiple metric tons of payload on the lunar surface.
The top deck and lower bays easily accommodate a wide variety of payloads, including large payloads and ESPA-class payloads with standard ring port interfaces. There are lower mounting locations for payloads, useful for closer access to the lunar surface and off-loading. The lander provides kilowatts of power to payloads using its fuel cells, allowing for long mission durations and the ability to last through the lunar night.
Looking at the entire program, as we know, the agency previously contracted SpaceX to demonstrate an initial human landing system for the Artemis III mission. Under that contract, the agency also directed SpaceX to evolve its design to meet the agency’s requirements for sustainable exploration and to demonstrate the lander on Artemis IV. As a result of the contract with Blue Origin to demonstrate on Artemis V a lander that meets these same sustainable lander requirements, including capabilities for increased crew size, longer mission duration, and delivery of more mass to the Moon, multiple providers will be available to compete for future opportunities to fulfill NASA’s lunar surface access needs for Artemis missions. In the near future, we can expect a lot more updates on the BE-7 engine which is integral to the Blue Origin lunar lander.
Conclusion
Blue Origin is working to increase production of its BE-7 engine as more testing and work is necessary. This engine will play an important role in landing NASA astronauts on the Moon during Artemis V. In order for this to happen however the company needs to continue developing and testing the hardware. We will have to wait and see how it progresses and the impact it has on the space industry.