| Country of origin | United States |
|---|---|
| Manufacturer | Blue Origin |
| Predecessor | BE-3 |
| Liquid-fuel engine | |
| Propellant | Liquid oxygen / Liquefied natural gas |
| Under development | |
| Performance | |
| Thrust (SL) | 2,400 kN (550,000 lbf) |
| Chamber pressure | 13,400 kPa (1,950 psi) |
| Gimbal range | ±5° |
| Used in | |
| Vulcan New Glenn | |
The Blue Engine 4 or BE-4 is an oxygen rich liquefied-natural-gas-fueled staged-combustion rocket engine under development by Blue Origin. The BE-4 is being developed with private and public funding. The engine has been designed to produce 2,400 kilonewtons (550,000 lbf) of thrust at sea level.
It was initially planned for the engine to be used exclusively on a Blue Origin proprietary launch vehicle, New Glenn, the company's first orbital rocket. However, it was announced in 2014 that the engine would also be used on the United Launch Alliance (ULA) Vulcan launch vehicle, the successor to the Atlas V launch vehicle. Final engine selection by ULA happened in September 2018.
First flight test of the new engine is expected no earlier than 2021.
History
Blue Origin began work on the BE-4 in 2011, although no public announcement was made until September 2014. This is their first engine to combust liquid oxygen and liquid methane propellants. In September 2014—in a choice labeled "a stunner" by SpaceNews—the large launch vehicle manufacturer and launch service provider United Launch Alliance selected the BE-4 as the main engine for a new primary launch vehicle.
As of April 2015, the engine development work was being carried
out in two parallel programs. One program is testing full-scale versions
of the BE-4 powerpack, which are the set of valves and turbopumps that provide the proper fuel/oxidizer mix to the injectors and combustion chamber. The second program is testing subscale versions of the engine's injectors.
Also in early 2015, the company indicated it is planning to begin
full-scale engine testing in late 2016, and that they expected to
complete development of the engine in 2017.
As of September 2015, Blue Origin had completed more than 100 development tests of several elements of the BE-4, including the preburner and a "regeneratively-cooled thrust chamber
using multiple full-scale injector elements". The tests were used to
confirm the theoretical model predictions of "injector performance, heat transfer, and combustion stability", and data collected is being used to refine the engine design.
There was an explosion on the test stand during 2015 during powerpack
testing. Blue Origin built two larger and redundant test stands to
follow, capable of testing the full thrust of the BE-4.
In January 2016, Blue Origin announced that they intended to
begin testing full engines of the BE-4 on ground test stands prior to
the end of 2016.
Following a factory tour in March 2016, journalist Eric Berger noted
that a large part of "Blue Origin’s factory has been given over to
development of the Blue Engine-4".
Initially, both first-stage and second-stage versions of the
engine were planned. The second stage of the initial New Glenn design
was to have shared the same stage diameter as the first stage and use a
single vacuum-optimized BE-4, the BE-4U.
The first engine was fully assembled in March 2017.
Also in March, United Launch Alliance indicated that the economic risk
of the Blue Origin engine selection option had been retired, but that
the technical risk on the project would remain until a series of engine
firing tests were completed later in 2017. A test anomaly occurred on 13 May 2017 and Blue Origin reported that they lost a set of powerpack hardware.
In June 2017, Blue Origin announced that they would build a new facility in Huntsville, Alabama to manufacture the large BE-4 cryogenic rocket engine.
The BE-4 was first test fired, at 50% thrust for 3 seconds, in October 2017. By March 2018, the BE-4 engine had been tested at 65% of design thrust for 114 seconds with a goal expressed in May to achieve 70% of design thrust in the next several months.
By September 2018, multiple hundreds of seconds of engine testing had
been completed, including one test of over 200 seconds duration.
In October 2018, Blue Origin President Bob Smith announced that the first launch of the New Glenn had been moved back to 2021, which will be the first flight test of the BE-4.
By February 2019, the BE-4 had acquired a total of 1800 seconds
of hot fire testing on ground test stands, but had yet to be tested
above 1.8 meganewtons (400,000 lbf) pounds of thrust, about 73 percent
of the engine's rated thrust of 2.4 MN (550,000 lbf).
In August 2019, Blue Origin announced that BE-4 was undergoing full power engine tests.
Blue Origin BE-4 rocket engine powerhead and combustion chamber, April 2018—liquid methane inlet side view. This was the first BE-4 engine to be hotfire tested; test occurred on 18 October 2017.
Applications
As of 2017, the BE-4 was being considered for use on two launch vehicles currently in development. Prior to this, a modified derivative of the BE-4 was also being considered for the experimental XS-1 spaceplane for a US military project, but was not selected.
Atlas V successor - Vulcan
In late 2014, Blue Origin signed an agreement with United Launch Alliance to co-develop the BE-4 engine and to commit to use the new engine on the Vulcan launch vehicle, a successor to the Atlas V, which would replace the single Russian-made RD-180 engine. Vulcan will use two of the 2,400 kN (550,000 lbf) BE-4 engines on each first stage. The engine development program began in 2011.
The ULA partnership announcement came after months of uncertainty about the future of the Russian RD-180 engine that has been used in the ULA Atlas V
rocket for over a decade. Geopolitical concerns had come about that
created serious concerns about the reliability and consistency of the supply chain for the procurement of the Russian engine. ULA expects the first flight of the new launch vehicle no earlier than 2019.
Since early 2015, the BE-4 has been in competition with the AR1 engine for the Atlas V RD-180 replacement program. While the BE-4 is a methane engine, the AR1, like the RD-180, is kerosene-fueled. In February 2016, the US Air Force issued a contract that provides partial development funding of up to US$202 million to ULA in order to support use of the Blue BE-4 engine on the ULA Vulcan launch vehicle.
Initially, only US$40.8 million will be disbursed by the government with US$40.8 million additional to be spent by a ULA subsidiary on Vulcan BE-4 development. Although US$536 million was the original USAF contract amount to Aerojet Rocketdyne (AJR) to advance development of the AR1 engine, as an alternative for powering the Vulcan rocket,
by June 2018, the USAF had renegotiated the agreement with AJR and
decreased the Air Force contribution—5/6ths of the total cost—to US$294 million. AJR is putting no additional private funds into the engine development effort after early 2018.
Bezos noted in 2016 that the Vulcan launch vehicle is being
designed around the BE-4 engine; ULA switching to the AR1 would require
significant delays and money on the part of ULA.
This point has also been made by ULA executives, who have also
clarified that the BE-4 is likely to cost 40% less than the AR1, as well
as benefit from Bezos capacity to "make split-second investment
decisions on behalf of BE-4, and has already demonstrated his
determination to see it through. [whereas the] AR1, in contrast, depends
mainly on U.S. government backing, meaning Aerojet Rocketdyne has many
phone numbers to dial to win support".
New Glenn launch vehicle
The engine is to be used on the Blue Origin large orbital launch vehicle New Glenn, a 7.0-meter (23 ft)-diameter two-stage orbital launch vehicle with an optional third stage and a reusable first stage. The first flight and orbital test is planned for no earlier than 2021, although the company had earlier expected the BE-4 might be tested on a rocket flight as early as 2020.
The first stage will be powered by seven BE-4 engines and will be reusable, landing vertically. The second stage of New Glenn will share the same diameter and use two BE-3 vacuum-optimized hydrolox engines. The second stage will be expendable.
XS-1 engine
Boeing secured a contract to design and build the DARPA XS-1 reusable spaceplane in 2014. The XS-1 is to accelerate to hypersonic speed at the edge of the Earth's atmosphere to enable its payload to reach orbit. In 2015, it was believed a modified derivative of the BE-4 engine was to power the craft. In 2017, the contract award selected the RS-25-derived Aerojet Rocketdyne AR-22 engine instead.
Availability and use
Blue
Origin has indicated that they intend to make the engine commercially
available, once development is complete, to companies beyond ULA, and
also plans to utilize the engine in Blue Origin's own new orbital launch
vehicle. As of March 2016, Orbital ATK was also evaluating Blue engines for its launch vehicles.
The BE-4 uses liquid methane rather than more commonly used rocket fuels such as kerosene. This approach allows for autogenous pressurization,
which is the use of gaseous fuel to pressurize remaining liquid fuel.
This is beneficial because it eliminates the need for costly and complex
pressurization systems which require storage of a pressurizing gas,
such as helium.
Although all early BE-4 components and full engines to support
the test program were built at Blue's headquarters location in Kent,
Washington, production of the BE-4 will be in Huntsville, Alabama. Testing and support of the reusable BE-4s will occur at the company's orbital launch facility at Exploration Park in Florida, where Blue Origin is investing more than US$200 million in facilities and improvements.
Technical specifications
The BE-4 is a staged combustion engine, with a single oxygen rich preburner, and a single turbine driving both the fuel and oxygen pumps . The cycle is similar to the kerosene-fueled RD-180 currently used on the Atlas V, although it uses only a single combustion chamber and nozzle.
The BE-4 is designed for long life and high reliability,
partially by aiming the engine to be a "medium-performing version of a
high-performance architecture". Hydrostatic bearings are used in the turbopumps rather than the more typical ball and roller bearings specifically to increase reliability and service life.
- Thrust (sea level): 2,400 kN (550,000 lbf) at full power
- Chamber pressure: 13,400 kPa (1,950 psi), substantially lower than the 26,000 kPa (3,700 psi) of the RD-180 engine that ULA wants to replace
- Designed for reusability
- Design life: 100 launches and landings
- Restartable during flight, via head-pressure start of the turbine during coast
- Deep throttling capability to 65% power or lower
