BE-4

Following Aerojet's acquisition of Pratt & Whitney Rocketdyne in 2012, Blue Origin president Rob Meyerson saw an opportunity to fill a gap in the defense industrial base.{{Citation |title=#01 Building Blue Origin with Rob Meyerson |url=https://open.spotify.com/episode/7KT9YLblFP6nLsby0jkGsh |access-date=19 May 2021 |language=en}} Blue Origin publicly entered the liquid rocket engine business by partnering with ULA and other companies on the development of BE-4. Meyerson announced the selection of Huntsville, AL as the location of Blue Origin's rocket engine production factory in June 2017.{{Cite news |last=Berger |first=Eric |date=28 June 2017 |title=Why is Jeff Bezos building rocket engines in Alabama? He's playing to win |url=https://arstechnica.com/science/2017/06/heres-why-jeff-bezos-is-building-rocket-engines-in-alabama/ |access-date=19 May 2021 |work=Ars Technica}}

Blue Origin began work on the BE-4 in 2011,{{Cite news |last=Foust |first=Jeff |date=30 September 2015 |title=Blue Origin Reaches Milestone in BE-4 Engine Development |url=https://spacenews.com/blue-origin-reaches-milestone-in-be-4-engine-development/ |access-date=30 December 2021 |work=Space News}} although the public announcement was made in September 2014. This was their first engine to combust liquid oxygen and methane propellants.

In September 2014 ULA selected BE-4 as the main engine for the Vulcan launch vehicle. Vulcan is a successor to the Atlas V, and BE-4 would replace the Russian-made RD-180 engine.{{Cite news |last=Mike Gruss |date=24 April 2015 |title=Evolution of a Plan: ULA Execs Spell Out Logic Behind Vulcan Design Choices |url=http://spacenews.com/evolution-of-a-plan-ula-execs-spell-out-logic-behind-vulcan-design-choices |url-status=live |archive-url=https://archive.today/20150425215959/http://spacenews.com/evolution-of-a-plan-ula-execs-spell-out-logic-behind-vulcan-design-choices/ |archive-date=25 April 2015 |access-date=25 April 2015 |work=Space News}} Blue Origin said that the "BE-4 would be 'ready for flight' by 2017". Blue Origin indicated that they intend to make the engine available to companies beyond ULA.{{Cite news |last=Foust |first=Jeff |date=22 September 2014 |title=Commercial crew and commercial engines |url=http://www.thespacereview.com/article/2605/1 |url-status=live |archive-url=https://web.archive.org/web/20210326153026/https://www.thespacereview.com/article/2605/1 |archive-date=26 March 2021 |access-date=1 October 2014 |work=The Space Review}}

By April 2015, two parallel development programs were under way. One program was testing full-scale versions of the BE-4 powerpack, the set of valves and turbopumps that provide the proper fuel/oxidizer mix to the injectors and combustion chamber. The second program was testing subscale versions of the engine's injectors.{{Cite news |last=Jeff Foust |date=7 April 2015 |title=Blue Origin Completes BE-3 Engine as BE-4 Work Continues |url=http://spacenews.com/blue-origin-completes-be-3-engine-as-be-4-work-continues |url-status=live |archive-url=https://archive.today/20150408034853/http://spacenews.com/blue-origin-completes-be-3-engine-as-be-4-work-continues/ |archive-date=8 April 2015 |access-date=8 April 2015 |work=Space News}} The company planned to begin full-scale engine testing in late 2016 and expected to complete development in 2017.

By 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 was used to refine the engine design.{{Cite web |date=20 September 2015 |title=Blue Origin Completes More Than 100 Staged-Combustion Tests in Development of BE-4 Engine |url=https://www.blueorigin.com/news/news/blue-origin-completes-more-than-100-staged-combustion-tests-in-development |url-status=dead |archive-url=https://web.archive.org/web/20170921144921/https://www.blueorigin.com/news/news/blue-origin-completes-more-than-100-staged-combustion-tests-in-development |archive-date=21 September 2017 |access-date=12 January 2016 |publisher=Blue Origin}} A test device exploded 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.{{Cite news |last=de Selding |first=Peter B. |date=16 March 2016 |title=ULA intends to lower its costs, and raise its cool, to compete with SpaceX |url=http://spacenews.com/ula-intends-to-lower-its-costs-and-raise-its-cool-to-compete-with-spacex/ |url-status=live |archive-url=https://archive.today/20160317125310/http://spacenews.com/ula-intends-to-lower-its-costs-and-raise-its-cool-to-compete-with-spacex/ |archive-date=17 March 2016 |access-date=19 March 2016 |work=SpaceNews |quote=[Blue Origin] did blow up one of their engines on the test stand ... restart the engine ... head pressure start of the turbine ... [Blue] blew up a powerpack under test ... [Bezos] opened up his checkbook, ... need to rebuild test stand, move up to 500 k powerpack for the Vulcan BE-4 engine; not one but two test stands ... agility to ... write with own checkbook is just refreshing }}

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.{{Cite news |last=Berger |first=Brian |date=23 January 2016 |title=Launch. Land. Repeat: Blue Origin posts video of New Shepard's Friday flight |url=http://spacenews.com/launch-land-repeat-blue-origin-posts-video-of-new-shepards-friday-flight/ |access-date=24 January 2016 |work=SpaceNews |quote=Also this year, we'll start full-engine testing of the BE-4}} 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".{{Cite news |last=Berger |first=Eric |date=9 March 2016 |title=Behind the curtain: Ars goes inside Blue Origin's secretive rocket factory |url=https://arstechnica.com/science/2016/03/behind-the-curtain-ars-goes-inside-blue-origins-secretive-rocket-factory/ |url-status=live |archive-url=https://web.archive.org/web/20160309174506/http://arstechnica.com/science/2016/03/behind-the-curtain-ars-goes-inside-blue-origins-secretive-rocket-factory/ |archive-date=9 March 2016 |access-date=9 March 2016 |work=Ars Technica}}

Initially, both first-stage and second-stage versions of the engine were planned. The second stage of the initial New Glenn design was to share the same stage diameter as the first stage and use a single vacuum-optimized BE-4, the BE-4U.{{Cite news |last=Bergin |first=Chris |date=12 September 2016 |title=Blue Origin introduce the New Glenn orbital LV |url=https://www.nasaspaceflight.com/2016/09/blue-origin-new-glenn-orbital-lv/ |url-status=live |archive-url=https://web.archive.org/web/20160913152524/https://www.nasaspaceflight.com/2016/09/blue-origin-new-glenn-orbital-lv/ |archive-date=13 September 2016 |access-date=13 November 2018 |work=NASASpaceFlight.com |quote=the two-stage New Glenn is 270 feet tall, and its second stage is powered by a single vacuum-optimized BE-4 engine (the BE-4U)}} Later, they backed away from this plan.

The first engine was fully assembled in March 2017.{{Cite tweet |number=838748139964272640 |user=JeffBezos |title=1st BE-4 engine fully assembled. 2nd and 3rd following close behind. #GradatimFerociter |date=6 March 2017 |access-date=6 March 2017 |archive-url=https://web.archive.org/web/20170307165514/https://twitter.com/JeffBezos/status/838748139964272640 |archive-date=7 March 2017}}{{Primary source inline|date=June 2020}} Also in March, ULA 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 engine firing tests were completed.{{Cite web |date=5 April 2017 |title=Bruno: Vulcan engine downselect is Blue's to lose |url=https://spacenews.com/bruno-vulcan-engine-downselect-is-blues-to-lose/ |url-status=live |archive-url=https://archive.today/20170406175055/http://spacenews.com/bruno-vulcan-engine-downselect-is-blues-to-lose/ |archive-date=6 April 2017 |access-date=17 March 2021 |website=SpaceNews}} In June 2017, Blue Origin announced that they would build a new facility in Huntsville, Alabama, to manufacture BE-4.{{Cite web |last=Berger |first=Eric |date=28 June 2017 |title=Why is Jeff Bezos building rocket engines in Alabama? He's playing to win |url=https://arstechnica.com/science/2017/06/heres-why-jeff-bezos-is-building-rocket-engines-in-alabama/ |url-status=live |archive-url=https://web.archive.org/web/20170703184505/https://arstechnica.com/science/2017/06/heres-why-jeff-bezos-is-building-rocket-engines-in-alabama/ |archive-date=3 July 2017 |access-date=6 July 2017}}{{update after|2019}}

BE-4 was first test-fired, at 50% thrust for 3 seconds, in October 2017,{{Cite news |last=Berger |first=Eric |date=19 October 2017 |title=Blue Origin just sent a jolt through the aerospace industry |url=https://arstechnica.com/science/2017/10/blue-origin-has-successfully-tested-its-powerful-be-4-rocket-engine/ |url-status=live |archive-url=https://web.archive.org/web/20171019203559/https://arstechnica.com/science/2017/10/blue-origin-has-successfully-tested-its-powerful-be-4-rocket-engine/ |archive-date=19 October 2017 |access-date=19 October 2017 |publisher=Ars Technica}} rising by March 2018, to 65% for 114 seconds,{{Citation |last=Blue Origin |title=BE-4 Engine test: 65% power level and 114 seconds |date=14 March 2018 |url=https://www.youtube.com/watch?v=Fp0WgodhR7s |access-date=20 March 2018 |archive-url=https://web.archive.org/web/20180928235910/https://www.youtube.com/watch?v=Fp0WgodhR7s |archive-date=28 September 2018 |url-status=live}}. by February 2019 to 73%,{{Cite news |last=Mosher |first=Dave |date=23 February 2019 |title=Jeff Bezos just gave a private talk in New York. From utopian space colonies to dissing Elon Musk's Martian dream, here are the most notable things he said. |url=https://www.businessinsider.com/jeff-bezos-blue-origin-wings-club-presentation-transcript-2019-2 |url-status=live |archive-url=https://web.archive.org/web/20190224151730/https://www.businessinsider.com/jeff-bezos-blue-origin-wings-club-presentation-transcript-2019-2 |archive-date=24 February 2019 |access-date=25 February 2019 |work=Business Insider}} and by August 2019 to 100%.{{Cite news |last=Alan Boyle |date=2 August 2019 |title=Jeff Bezos touts a full-power firing of Blue Origin's next-generation BE-4 rocket engine |url=https://www.geekwire.com/2019/jeff-bezos-touts-full-power-firing-blue-origins-next-generation-4-rocket-engine/ |access-date=14 May 2023 |work=geekwire.com}} Testing and support took place at the company's orbital launch facility at Exploration Park in Florida, where Blue Origin invested more than {{USD|200 million}} in facilities and improvements.{{Cite news |last=Price |first=Wayne T. |date=12 March 2016 |title=Jeff Bezos' Blue Origin could change the face of space travel |url=http://www.floridatoday.com/story/news/local/2016/03/12/jeff-bezos-blue-origin-amazon-space-exploration-brevard-county-florida/81649214/ |url-status=live |archive-url=https://web.archive.org/web/20180106065214/http://www.floridatoday.com/story/news/local/2016/03/12/jeff-bezos-blue-origin-amazon-space-exploration-brevard-county-florida/81649214/ |archive-date=6 January 2018 |access-date=13 March 2016 |work=Florida Today}}

File:Blue Origin BE-4 rocket engine, sn 103, April 2018 -- LCH4 inlet side view, minus nozzle.jpg and combustion chamber, April 2018—methane inlet side view. This was the first BE-4 engine to be hotfire tested; the test occurred on 18 October 2017.]]

In October 2018, Blue Origin President Bob Smith announced that the first New Glenn launch had been moved back to 2021,{{Cite tweet |number=1050069752679301120 |user=b0yle |title=Latest schedule from @blueorigin CEO Bob Smith at #afasummit2018: People to fly on #NewShepard starting n first hal… |date=10 October 2018}} followed in 2021 by an additional slip to late 2022.{{Cite web |date=25 February 2021 |title=Blue Origin delays first launch of New Glenn to late 2022 |url=https://spacenews.com/blue-origin-delays-first-launch-of-new-glenn-to-late-2022/ |url-status=live |archive-url=https://web.archive.org/web/20210922131539/https://spacenews.com/blue-origin-delays-first-launch-of-new-glenn-to-late-2022/ |archive-date=22 September 2021 |access-date=25 February 2021 |publisher=SpaceNews}} The first flight test of the BE-4 was then redirected for the initial Vulcan Centaur launch rather than on New Glenn.

In July 2020, the first pathfinder BE-4 was delivered to ULA for integration testing with Vulcan Centaur.{{Cite web |date=2 July 2020 |title=Blue Origin delivers the first BE-4 engine to United Launch Alliance |url=https://spacenews.com/blue-origin-delivers-the-first-be-4-engine-to-united-launch-alliance/ |access-date=14 August 2020 |website=SpaceNews}}{{Cite web |date=5 July 2020 |title=Blue Origin Rocket Engine Delivered to US' United Launch Alliance, to End Russian Imports |url=https://www.defenseworld.net/news/27350/Blue_Origin_Rocket_Engine_Delivered_to_US____United_Launch_Alliance__to_End_Russian_Imports#.XzcNliSYXU8 |url-status=live |archive-url=https://web.archive.org/web/20200807203133/https://www.defenseworld.net/news/27350/Blue_Origin_Rocket_Engine_Delivered_to_US____United_Launch_Alliance__to_End_Russian_Imports#.XzcNliSYXU8 |archive-date=7 August 2020 |access-date=14 August 2020 |website=Defense World}}

In August 2020, ULA CEO Tory Bruno stated that the second test BE-4 would be delivered soon, followed quickly by flight-qualified ones.{{Cite web |date=11 August 2020 |title=Tory Bruno on ULA's big win: 'We knew we were going to be competitive' |url=https://spacenews.com/tory-bruno-on-ulas-big-win-we-knew-we-were-going-to-be-competitive/ |access-date=7 February 2023 |website=SpaceNews}} He noted an ongoing issue with the BE-4's turbopumps. At the time, Blue Origin was still troubleshooting the 75,000-horsepower pumps.{{Cite web |date=20 August 2020 |title=United launch alliance space force spacex contract |url=https://www.bizjournals.com/denver/news/2020/08/20/united-launch-alliance-space-force-spacex-contract.html |url-status=live |archive-url=https://web.archive.org/web/20210205075434/https://www.bizjournals.com/denver/news/2020/08/20/united-launch-alliance-space-force-spacex-contract.html |archive-date=5 February 2021 |access-date=17 March 2021 |website=www.bizjournals.com}} The issue continued until 2022.

On 31 October 2022, Blue Origin announced that the first two BE-4 engines were being integrated on a Vulcan rocket.{{Cite web |last=Boyle |first=Alan |date=31 October 2022 |title=Blue Origin completes delivery of BE-4 rocket engines for first ULA Vulcan launch |url=https://www.geekwire.com/2022/blue-origin-delivery-be-4-rocket-engines-ula-vulcan/ |access-date=7 November 2022 |website=GeekWire |language=en-US}}

On 11 May 2023, Bruno stated that BE-4 qualification testing had been completed "several weeks ago", i.e,, by the end of April 2023.{{Cite tweet |number=1656612692097138688 |user=torybruno |title=Yes. BE qual was complete several weeks ago}}

On 30 June 2023, a BE-4 engine exploded 10 seconds into testing, damaging the test stand.{{Cite web |last=Sheetz |first=Michael |date=11 July 2023 |title=Jeff Bezos' Blue Origin rocket engine explodes during testing |url=https://www.cnbc.com/2023/07/11/jeff-bezos-blue-origin-be-4-rocket-engine-explodes-during-testing.html |access-date=12 July 2023 |website=CNBC |language=en}}

On 8 January 2024, ULA successfully launched Vulcan-Centaur{{Citation |title=Vulcan Centaur |date=8 January 2024 |work=Wikipedia |url=https://en.wikipedia.org/w/index.php?title=Vulcan_Centaur&oldid=1194310124 |access-date=8 January 2024 |language=en}}. powered by BE-4.

As of 2024, there were two BE-4 production lines, one to supply ULA and one for New Glenn.{{Cite web |last=Atkinson |first=Ian |date=4 June 2024 |title=Blue Origin works towards New Glenn debut, ramps BE-4 deliveries |url=https://www.nasaspaceflight.com/2024/06/new-glenn-test-be4-ramp/ |access-date=16 June 2024 |website=NASASpaceFlight.com |language=en-US}}

{{Further|Vulcan Centaur}}

Vulcan uses two of the {{convert|550000|lbf|kN|order=flip|abbr=on}} BE-4 engines on each first stage.{{Cite news |last=Achenbach |first=Joel |date=17 September 2014 |title=Jeff Bezos's Blue Origin to supply engines for national security space launches |url=https://www.washingtonpost.com/national/health-science/jeff-bezos-and-blue-origin-to-supply-engines-for-national-security-space-launches/2014/09/17/59f46eb2-3e7b-11e4-9587-5dafd96295f0_story.html |url-status=live |archive-url=https://web.archive.org/web/20140925075923/http://www.washingtonpost.com/national/health-science/jeff-bezos-and-blue-origin-to-supply-engines-for-national-security-space-launches/2014/09/17/59f46eb2-3e7b-11e4-9587-5dafd96295f0_story.html |archive-date=25 September 2014 |access-date=27 September 2014 |work=The Washington Post}}{{Cite web |date=17 September 2014 |title=ULA taps Blue Origin for powerful new rocket engine |url=http://www.spaceflightnow.com/news/n1409/17ulablueorigin/?fb_comment_id=839393116095341_839434626091190#.V-GLjnoSNWg |url-status=live |archive-url=https://web.archive.org/web/20161220175736/http://www.spaceflightnow.com/news/n1409/17ulablueorigin/?fb_comment_id=839393116095341_839434626091190#.V-GLjnoSNWg |archive-date=20 December 2016 |access-date=8 April 2015 |publisher=Spaceflightnow.com}}{{Cite news |last=Ferster |first=Warren |date=17 September 2014 |title=ULA To Invest in Blue Origin Engine as RD-180 Replacement |url=https://spacenews.com/41901ula-to-invest-in-blue-origin-engine-as-rd-180-replacement/ |access-date=11 June 2021 |work=Space News}}

The BE-4 competed with and defeated the AR1 engine for the Atlas V RD-180 replacement program. The AR1, like the RD-180, is kerosene-fueled.{{Cite news |last=Mike Gruss |date=27 February 2015 |title=Timing of Russian Engine Ban Puts ULA, Air Force, in a Bind |url=http://spacenews.com/timing-of-russian-engine-ban-puts-ula-air-force-in-a-bind/ |url-status=live |archive-url=https://archive.today/20150228074908/http://spacenews.com/timing-of-russian-engine-ban-puts-ula-air-force-in-a-bind/ |archive-date=28 February 2015 |access-date=8 April 2015 |publisher=Space News}}

In February 2016, the US Air Force issued a contract that provides partial development funding of up to {{USD|202 million}} to ULA in order to support use of the Blue Origin BE-4 engine on the ULA Vulcan launch vehicle.{{Cite news |last=Gruss |first=Mike |date=29 February 2016 |title=Aerojet Rocketdyne, ULA win Air Force propulsion contracts |url=http://spacenews.com/aerojet-rocketdyne-ula-win-air-force-propulsion-contracts/ |url-status=live |archive-url=https://archive.today/20161218192958/http://spacenews.com/aerojet-rocketdyne-ula-win-air-force-propulsion-contracts/ |archive-date=18 December 2016 |access-date=1 March 2016 |work=SpaceNews}}{{Cite web |title=defense.gov |url=https://www.defense.gov/News/Contracts/Contract/Article/682238/ |url-status=live |archive-url=https://web.archive.org/web/20160301145231/http://www.defense.gov/News/Contracts/Contract-View/Article/682238 |archive-date=1 March 2016 |access-date=1 March 2016}}

The original USAF contract to Aerojet Rocketdyne (AR) to advance development of the AR1 engine was {{USD|536 million}}, but by June 2018, the USAF had decreased its contribution—5/6ths of the total cost—to {{USD|294 million}}. ARR put no additional private funds into effort after early 2018.{{Cite news |last=Foust |first=Jeff |date=25 September 2018 |title=Aerojet Rocketdyne seeks other customers for AR1 engine |url=https://spacenews.com/aerojet-rocketdyne-seeks-other-customers-for-ar1-engine/ |access-date=7 February 2023 |work=SpaceNews |quote='It's performing quite well', Blue Origin Chief Executive Bob Smith said of BE-4 on the same panel as Bruno. 'We've gone through several hundred seconds of firing, including an over 200-second firing of that engine, so we're feeling very good about its progress and what we're going to be able to deliver to the market, as well as for our own consumption.'}}

Vulcan launched on 8 January 2024. The engines performed flawlessly, propelling Peregrine Mission One to Trans-lunar injection. Vulcan was the first methane-fueled rocket to reach orbit on its first attempt, and the first to reach orbit from the US.{{Cite news |last=Belam |first=Martin |date=8 January 2024 |title=Nasa Peregrine 1 launch: Vulcan Centaur rocket carrying Nasa moon lander lifts off in Florida – live updates |url=https://www.theguardian.com/science/live/2024/jan/08/nasa-peregrine-1-launch-rocket-moon-latest-news-updates-live |access-date=8 January 2024 |work=the Guardian |language=en-GB |issn=0261-3077}}

{{main|New Glenn}}

The BE-4 is used on Blue Origin's New Glenn, a {{convert|23|ft|disp=flip|adj=on|sp=us}}-diameter two-stage orbital launch vehicle with an optional third stage. The first stage is powered by seven BE-4 engines and is reusable, landing vertically. The second stage has same diameter and use two BE-3 vacuum-optimized LH2/LOX engines.{{Cite news |date=29 March 2018 |title=Blue Origin switches engines for New Glenn second stage |url=http://spacenews.com/blue-origin-switches-engines-for-new-glenn-second-stage/ |url-status=live |archive-url=https://archive.today/20180329194940/http://spacenews.com/blue-origin-switches-engines-for-new-glenn-second-stage/ |archive-date=29 March 2018 |access-date=28 April 2018 |work=SpaceNews.com}} The second stage is expendable.

New Glenn launched on 16 January 2025, in which all of the seven engines performed well in ascent flight, except on the landing attempt, where the first stage booster failed at some point during the atmospheric reentry.

{{Further|XS-1 (spacecraft)}}

Boeing secured a contract to design and build the DARPA XS-1 reusable spaceplane in 2014. The XS-1 was to accelerate to hypersonic speed at the edge of the Earth's atmosphere to enable its payload to reach orbit.{{Cite web |date=15 July 2014 |title=Work Commences on Experimental Spaceplane (XS-1) Designs |url=http://www.darpa.mil/news-events/2014-07-15 |url-status=live |archive-url=https://web.archive.org/web/20161030212808/http://www.darpa.mil/news-events/2014-07-15 |archive-date=30 October 2016 |access-date=20 September 2016 |publisher=Darpa.mil}} In 2015, a modified BE-4 was believed to be the primary source of propulsion.{{Cite web |last=David Axe |date=3 August 2015 |title=Pentagon Preps for Orbital War With New Spaceplane |url=http://www.thedailybeast.com/articles/2015/08/03/pentagon-preps-for-orbital-war-with-new-space-plane.html |url-status=live |archive-url=https://web.archive.org/web/20150804054537/http://www.thedailybeast.com/articles/2015/08/03/pentagon-preps-for-orbital-war-with-new-space-plane.html |archive-date=4 August 2015 |access-date=3 August 2015 |website=The Daily Beast}} In May 2017, the contract award selected the RS-25-derived Aerojet Rocketdyne AR-22 engine instead.{{Cite web |date=24 May 2017 |title=Aerojet Rocketdyne Selected As Main Propulsion Provider for Boeing and DARPA Experimental Spaceplane |url=http://www.rocket.com/article/aerojet-rocketdyne-selected-main-propulsion-provider-boeing-and-darpa-experimental |access-date=25 May 2017}} The XS-1 was cancelled in 2020.{{Cite web |last=Jason Rhian |date=7 May 2017 |title=DARPA selects rocket engine for XS-1 experimental spaceplane |url=http://www.spaceflightinsider.com/missions/defense/darpa-selects-rocket-engine-xs-1-experimental-spaceplane/ |url-status=live |archive-url=https://web.archive.org/web/20170627194741/http://www.spaceflightinsider.com/missions/defense/darpa-selects-rocket-engine-xs-1-experimental-spaceplane/ |archive-date=27 June 2017 |access-date=12 July 2017 |publisher=SpaceFlightInsider}}{{Cite web |date=22 January 2020 |title=Boeing drops out of DARPA Experimental Spaceplane program |url=https://spacenews.com/boeing-drops-out-of-darpa-experimental-spaceplane-program/ |url-status=live |archive-url=https://archive.today/20200826055346/https://spacenews.com/boeing-drops-out-of-darpa-experimental-spaceplane-program/ |archive-date=26 August 2020 |access-date=2 July 2020 |website=SpaceNews.com |language=en-US}}

As of March 2016, Orbital ATK was evaluating Blue Origin engines for its launch vehicles, although they eventually went in another direction.{{update after|2018|4|7}}

The BE-4 is a staged combustion cycle engine, with a single oxygen-rich preburner, and a single turbine driving both the fuel and oxygen pumps.{{Cite web |title=BE-4 Engine |url=https://www.blueorigin.com/engines/be-4/ |access-date=7 February 2023 |website=Blue Origin}} The cycle is similar to the kerosene-fueled RD-180 currently, 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.{{Cite news |last=Boyle |first=Alan |date=20 March 2017 |title=Jeff Bezos does a deep dive into bearings in Blue Origin's BE-4 rocket engine update |url=https://finance.yahoo.com/news/jeff-bezos-does-deep-dive-002201040.html |url-status=live |archive-url=https://web.archive.org/web/20180423102036/https://finance.yahoo.com/news/jeff-bezos-does-deep-dive-002201040.html |archive-date=23 April 2018 |access-date=23 April 2018 |work=Yahoo Finance |quote=[550,000 lbf thrust rocket engine] performance can involve a lot of wear and tear, particularly if you're using traditional ball and roller bearings. To maximize the engine's reusability, Blue Origin's team is taking a different approach. To keep the BE-4 running smoothly, Bezos says the turbine at the heart of the engine's turbopump will use a thin film of the fluid propellants as its bearings.}}

Using methane allows for autogenous pressurization, which is the use of gasified propellant to pressurize liquid propellant. This is beneficial because it eliminates the need for pressurization systems that require the storage of a pressurizing gas such as helium.

• Thrust (sea level): {{convert|550000|lbf|kN|disp=flip|lk=on|abbr=on}} at full power

• Chamber pressure: {{convert|2000|psi|MPa|disp=flip|abbr=on}}, substantially lower than the {{convert|3700|psi|MPa|disp=flip|abbr=on}} of the RD-180 and {{convert|35|MPa|psi|disp=|abbr=on}} of Raptor 3{{Cite tweet |number=1657249739925258240 |user=elonmusk |title=Raptor V3 just achieved 350 bar chamber pressure (269 tons of thrust). Congrats to @SpaceX propulsion team! Starship Super Heavy Booster has 33 Raptors, so total thrust of 8877 tons or 19.5 million pounds. |first=Elon |last=Musk |author-link=Elon Musk}}
• Designed for reusability — up to 100 flights{{Cite tweet |number=1011193080865648641 |user=CHenry_QA |title=Correction from Ariane: New Glenn first stage can do 25 missions, BE-4 engines designed for 100 flights each. |date=25 June 2018 |access-date=27 May 2019 |archive-url=https://web.archive.org/web/20210326153019/https://twitter.com/CHenry_QA/status/1011193080865648641 |archive-date=26 March 2021}}{{Cite web |last=Sheetz |first=Michael |date=18 April 2018 |title=Blue Origin's new rocket engine will be able to launch '100 full missions', CEO says |url=https://www.cnbc.com/2018/04/18/blue-origin-ceo-bob-smith-be-4-will-be-able-to-launch-100-missions.html |url-status=live |archive-url=https://web.archive.org/web/20190527132002/https://www.cnbc.com/2018/04/18/blue-origin-ceo-bob-smith-be-4-will-be-able-to-launch-100-missions.html |archive-date=27 May 2019 |access-date=27 May 2019 |publisher=CNBC}}
• Relightable in-flight via head-pressure start of the turbine
• Deep throttling capability to 40% power or lower{{Cite web |title=BE-4 Engine test: 65% power level and 114 seconds – YouTube |url=https://www.youtube.com/watch?v=Fp0WgodhR7s |url-status=live |archive-url=https://web.archive.org/web/20180928235910/https://www.youtube.com/watch?v=Fp0WgodhR7s |archive-date=28 September 2018 |access-date=14 March 2018 |website=YouTube}}

• Comparison of orbital rocket engines
• BE-3 – hydrogen-fueled engine currently in operation by Blue Origin
• Raptor – methane-fueled engine developed by SpaceX
• Merlin – kerosene-fueled operational engine by SpaceX
• RD-180 – modern Russian kerosene-fueled engine of comparable size

{{Reflist}}

• [https://web.archive.org/web/20160306100309/http://www.ulalaunch.com/ula-and-blue-origin-partner-with-air-force.aspx ULA February 2016 statement following US Air Force partial-funding of BE-4 development]
• {{Cite tweet |number=838748973598900225 |user=JeffBezos |title=BE-4 in Transport Cradle |first=Jeff |last=Bezos |author-link=Jeff Bezos |date=6 March 2017}}
• {{Cite news |last=Klotz |first=Irene |date=27 October 2017 |title=Blue Origin Fires Up BE-4 Methane-Fuel Rocket Engine |url=http://aviationweek.com/space/blue-origin-fires-be-4-methane-fuel-rocket-engine |work=Aviation Week & Space Technology |at=Blue Origin marks successful first hotfire of BE-4 rocket engine}}
• {{Cite tweet |number=1228340205586796544 |user=blueorigin |title=BE-4 update video |author=Blue Origin |author-link=Blue Origin |date=14 February 2020 |language=en-US}}

{{Rocket engines}}

{{Blue Origin}}

Category:Blue Origin rocket engines

Category:Rocket engines using methane propellant

Category:Rocket engines using the staged combustion cycle

Category:Rocket engines of the United States