Vulcan Centaur Explained
Vulcan Centaur |
Logo Upright: | 0.3 |
Function: | Heavy-lift launch vehicle |
Manufacturer: | United Launch Alliance |
Country-Origin: | United States |
Cpl: | About US$100–200 million[1] [2] |
Height: | : [3]
|
Diameter: | [4] |
Stages: | 2 |
Capacities: | Inclination: | 28.7° | Kilos: | [5] |
|
Status: | Operational |
Sites: | |
Launches: | 1 |
Success: | 1 |
First: | 8 January 2024[7] |
Stagedata: | Type: | booster | | Solid: | yes | Number: | 0, 2, 4, or 6 | Thrust: | each | Burntime: | 87.3 seconds |
Stageno: | First | Type: | stage | Vulcan | Burntime: | 299 seconds[8] [9] | Fuel: | LOX / |
|
Vulcan Centaur is a heavy-lift launch vehicle created and operated by United Launch Alliance (ULA). It is a two-stage-to-orbit launch vehicle consisting of the Vulcan first stage and the Centaur second stage. It replaces ULA's Atlas V and Delta IV rockets. It is principally designed for the National Security Space Launch (NSSL) program, which launches satellites for U.S. intelligence agencies and the Defense Department, but will also be used for commercial launches.
ULA began developing the Vulcan rocket in 2014, largely to compete with SpaceX's Falcon 9 and to comply with a Congressional requirement to stop using the Russian-made RD-180 engine that powers the Atlas V. The first flight of the Vulcan Centaur was initially slated for 2019, but was delayed multiple times by developmental problems with its BE-4 engine and the Centaur upper stage.[12] Vulcan Centaur launched for the first time on 8 January 2024 carrying Astrobotic Technology's Peregrine lunar lander, the first mission of NASA's Commercial Lunar Payload Services (CLPS) program.[13]
Description
The Vulcan Centaur uses technologies from ULA's Atlas V and Delta IV launch vehicles, plus newer gear for better performance and lower costs. The Vulcan first stage is similar in size as the Delta family's Common Booster Core, allowing ULA to reuse manufacturing equipment.
It uses two BE-4 engines built by Blue Origin that burn liquid oxygen and liquid methane (liquefied natural gas).[14] Methane burns cleaner than the kerosene used on Atlas, spewing less particle pollution and making it more suitable for engine reuse. Compared to the liquid hydrogen used on Delta, it is denser and has a greater temperature range, allowing fuel tanks to be smaller and lighter.[15] [16]
The second stage is the Centaur V, a larger and improved version of the Centaur III used on the Atlas, which is powered by two RL10 engines built by Aerojet Rocketdyne, fueled by liquid hydrogen and liquid oxygen.[17] The first stage can be supplemented by up to six GEM 63XL solid rocket boosters built by Northrop Grumman.[18] [19]
Vulcan Centaur offers heavy-lift capabilities in the footprint of a medium-lift launch vehicle. With a single core and six GEM boosters, the Vulcan Centaur can lift 27200kg (60,000lb) to low Earth orbit (LEO).[20] That is much more than the 18850kg (41,560lb) that the Atlas V could lift to LEO with a single core and five GEM boosters,[21] and nearly as much as the three-core Delta IV Heavy which could lift 28790kg (63,470lb) to LEO.[22]
Vulcan has been designed to meet the requirements of the National Security Space Launch program and is designed to achieve human-rating certification to allow the launch of a vehicle such as the Boeing Starliner or Sierra Nevada Dream Chaser.[23]
History
Background
ULA decided to develop the Vulcan Centaur in 2014 for two main reasons. First, its commercial and civil customers were flocking to SpaceX's cheaper Falcon 9 reusable launch vehicle, leaving ULA increasingly reliant on U.S. military and spy agency contracts.[24] [25] Second, Russia's annexation of Crimea in 2014 heightened Congressional discomfort with the Pentagon's reliance on the Atlas V, which used the made-in-Russia RD-180 engine. In 2016, Congress would pass a law barring the military from procuring launch services based on the RD-180 engine after 2022.[26]
In September 2014, ULA announced that it had picked the BE-4 engine from Blue Origin and fueled by liquid oxygen (LOX) and liquid methane (CH4) to replace the RD-180 on a new first-stage booster. The engine was already in its third year of development, and ULA said it expected the new stage and engine to start flying as soon as 2019. Two of the 550000lbf-thrust BE-4 engines were to be used on a new launch vehicle booster.[27] [28]
A month later, ULA restructured company processes and its workforce to reduce costs. The company said that the successor to Atlas V would blend existing Atlas V and Delta IV with a goal of halving the cost of the Atlas V rocket.
Announcement
In 2015, ULA announced the Vulcan rocket and a proposing to incrementally replace existing vehicles with it.[29] Vulcan deployment was expected to begin with a new first stage that was based on the Delta IV's fuselage diameter and production process, and initially expected to use two BE-4 engines or the AR1 as an alternative. The second stage was to be the existing Centaur III, already used on Atlas V. A later upgrade, the Advanced Cryogenic Evolved Stage (ACES), was planned to be introduced a few years after Vulcan's first flight. ULA also revealed a design concept for reuse of the Vulcan booster engines, thrust structure and first stage avionics, which could be detached as a module from the propellant tanks after booster engine cutoff; the module would re-enter the atmosphere behind an inflatable heat shield.[30]
Funding
Through the first several years, the ULA board of directors made quarterly funding commitments to Vulcan Centaur development.[31], the US government had committed about $1.2 billion in a public–private partnership to Vulcan Centaur development, with plans for more once ULA concluded a National Security Space Launch contract.[32]
By March 2016, the United States Air Force (USAF) had committed up to $202 million for Vulcan development. ULA had not yet estimated the total cost of development but CEO Tory Bruno said that "new rockets typically cost $2 billion, including $1 billion for the main engine". In March 2018, Bruno said the Vulcan-Centaur had been "75% privately funded" up to that point. In October 2018, following a request for proposals and technical evaluation, ULA was awarded $967 million to develop a prototype Vulcan launch system as part of the National Security Space Launch program.
Development, production, and testing
In September 2015, it was announced BE-4 rocket engine production would be expanded to allow more testing.[33] The following January, ULA was designing two versions of the Vulcan first stage; the BE-4 version has a diameter to support the use of the less dense methane fuel.[34] In late 2017, the upper stage was changed to the larger and heavier Centaur V, and the launch vehicle was renamed Vulcan Centaur.[35] In May 2018, ULA announced the selection of Aerojet Rocketdyne's RL10 engine for the Vulcan Centaur upper stage.[36] That September, ULA announced the selection of the Blue Origin BE-4 engine for Vulcan's first stage.[37] [38] In October, the USAF released an NSSL launch service agreement with new requirements, delaying Vulcan's initial launch to April 2021, after an earlier postponement to 2020.[39] [40] [41]
In August 2019, the parts of Vulcan's mobile launcher platform (MLP) were transported[42] to the Spaceflight Processing Operations Center (SPOC) near SLC-40 and SLC-41, Cape Canaveral, Florida. The MLP was fabricated in eight sections and moves at on rail bogies, standing tall.[43] In February 2021, ULA shipped the first completed Vulcan core booster to Florida for pathfinder tests ahead of the Vulcan's debut launch.[44] Testing continued proceeded with the pathfinder booster throughout that year.[45] [46]
In August 2019, ULA said Vulcan Centaur would first fly in early 2021, carrying Astrobotic Technology's Peregrine lunar lander.[47] [48] [49] By December 2020, the launch had been delayed to 2022 because of technical problems with the BE-4 main engine.[50] [51] In June 2021, Astrobotic said Peregrine would not be ready on time due to the COVID-19 pandemic, delaying the mission and Vulcan Centaur's first launch; further Peregrine delays put the launch of Vulcan into 2023.[52] [53] [54] In March 2023, a Centaur V test stage failed during a test sequence. To fix the problem, ULA changed the structure of the stage and built a new Centaur for Vulcan Centaur's maiden flight.[55] In October 2023, ULA announced they aimed to launch Vulcan Centaur by year's end.[56]
Certification flights
On 8 January 2024, Vulcan lifted off for the first time. The flight used the VC2S configuration, with two solid rocket boosters and a standard-length fairing. A 4-minute trans-lunar injection burn followed by payload separation put the Peregrine lander on a trajectory to the Moon. One hour and 18 minutes into the flight, the Centaur upper stage fired for a third time, sending it into a heliocentric orbit to test how it would behave in long missions, such as those required to send payloads to geostationary orbit.[57]
A failure in the Peregrine's propulsion system shortly after separation prevented it from landing on the Moon; Astrobotic said the Vulcan Centaur rocket performed without problems.[58]
On 14 August 2019, ULA won a commercial competition when it was announced the second Vulcan certification flight would be named SNC Demo-1, the first of seven Dream Chaser CRS-2 flights under NASA's Commercial Resupply Services program. They will use the four-SRB VC4 configuration.[59] The SNC Demo-1 was scheduled for launch no earlier than April 2024.[60]
After Vulcan Centaur's second certification mission, the rocket will be qualified for use on U.S. military missions.[61], Vulcan was to launch ULA's awarded 60% share of National Security Space Launch payloads from 2022 to 2027,[62] but delays occurred. The Space Force's USSF-51 launch in late 2022 was be the first national security classified mission, but in May 2021 the spacecraft was reassigned to an Atlas V to "mitigate schedule risk associated with Vulcan Centaur non-recurring design validation".[63] For similar reasons, the Kuiper Systems prototype flight was moved to an Atlas V rocket.[64]
After Vulcan's first launch in January 2024, developmental delays with the Dream Chaser led ULA to contemplate replacing it with a mass simulator so Vulcan could move ahead with the certification required by its Air Force contract.[65] Bloomberg News reported in May 2024 that United Launch Alliance was accruing financial penalties due to delays in the military launch contracts.[66] On 10 May, Air Force Assistant Secretary Frank Calvelli wrote to Boeing and Lockheed executives. "I am growing concerned with ULA's ability to scale manufacturing of its Vulcan rocket and scale its launch cadence to meet our needs", Calvelli wrote in the letter, a copy of which was obtained by the Washington Post. "Currently there is military satellite capability sitting on the ground due to Vulcan delays."[67] In June 2024, Bruno announced that Vulcan would make its second flight in September with an “inert payload” plus some “experiments and demonstrations” to help develop future technology for the Centaur upper stage.[68]
Versions and configurations
ULA has four-character designations for the various Vulcan Centaur configurations. They start with VC for the Vulcan first stage and the Centaur upper stage. The third character is the number of SRBs attached to the Vulcan—0, 2, 4 or 6—and the fourth denotes the payload-fairing length: S for Standard or L for Long .[69] For example, "VC6L" would represent a Vulcan first stage, a Centaur upper stage, six SRBs and a long-configuration fairing. The most powerful Vulcan Centaur will have a Vulcan first stage, a Centaur upper stage with RL10CX engines with a nozzle extension and six SRBs.[70]
Capabilities
The payload capacity of Vulcan Centaur versions are:[71]
Version | SRBs | Payload mass to... |
---|
ISS | SSO | MEO | GEO | GTO | Molniya | TLI | TMI |
---|
Vulcan Centaur VC0 | 0 | | | | | | | | |
Vulcan Centaur VC2 | 2 | | | | | | | | |
Vulcan Centaur VC4 | 4 | | | | | | | | |
Vulcan Centaur VC6 | 6 | | | | | | | | |
Vulcan Centaur VC6 (upgrade) | 6 | | | | | | | | | |
- Notes
These capabilities reflect NSSL requirements, plus room for growth.[72]
A Vulcan Centaur with six solid rocket boosters can put 27,200 kilograms into low Earth orbit, nearly as much as the three-core Delta IV Heavy.[73]
Vulcan Centaur launches
Future launches
Potential upgrades
Since 2015, ULA has spoken of several technologies that would improve the Vulcan launch vehicle's capabilities. These include first-stage improvements to make the most expensive components potentially reusable and second-stage improvements to allow the rocket to operate for months in Earth-orbit cislunar space.[74]
Long-endurance upper stages
See main article: Advanced Cryogenic Evolved Stage.
The ACES upper stage—fueled with liquid oxygen (LOX) and liquid hydrogen (LH) and powered by up to four rocket engines with the engine type yet to be selected—was a conceptual upgrade to Vulcan's upper stage at the time of the announcement in 2015. This stage could be upgraded to include Integrated Vehicle Fluids technology that would allow the upper stage to function in orbit for weeks instead of hours. The ACES upper stage was cancelled in September 2020,[75] and ULA said the Vulcan second stage would now be the Centaur V upper stage: a larger, more powerful version of the Dual Engine Centaur upper stage used by the Atlas V N22. A senior executive at ULA said the Centaur V design was also heavily influenced by ACES.[76]
However, ULA said in 2021 that it is working to add more value to upper stages by having them perform tasks such as operating as space tugs. CEO Tory Bruno says ULA is working on upper stages with hundreds of times the endurance of those currently in use.
SMART reuse
A method of main engine reuse called Sensible Modular Autonomous Return Technology (SMART) is a proposed upgrade for Vulcan Centaur. In the concept, the booster engines, avionics, and thrust structure detach as a module from the propellant tanks after booster engine cutoff. The engine module then falls through the atmosphere protected by an inflatable heat shield. After parachute deployment, the engine section splashes down, using the heatshield as a raft.[77] ULA estimated this technology could reduce the cost of the first stage propulsion by 90%, and 65% of the total first-stage cost. Although SMART reuse was not initially funded for development, from 2021 the higher launch cadence required to launch the Project Kuiper megaconstellation provided support for the concept's business case.[78] Prior to 2022, ULA intended to catch the engine section using a helicopter.
Vulcan Heavy
In September 2020, ULA announced that they were carefully studying a "Vulcan Heavy" variant with three booster cores. Speculation about a new variant had been rampant for months after an image of a model of that version popped on social media. ULA CEO Tory Bruno later tweeted a clearer image of the model and said it was the subject of ongoing study.[79] [80]
See also
External links
Notes and References
- Web site: Clark. Stephen. ULA needs commercial customers to close Vulcan rocket business case . Spaceflight Now. 22 April 2015. https://web.archive.org/web/20200605032007/https://spaceflightnow.com/2015/04/22/ula-needs-commercial-business-to-close-vulcan-rocket-business-case/. 5 June 2020. live.
- Web site: Shalal . Andrea . Klotz . Irene . 'Vulcan' rocket launch in 2019 may end U.S. dependence on Russia. Reuters. 13 April 2015. 13 April 2015. https://web.archive.org/web/20200605040759/https://www.reuters.com/article/lockheed-boeing-rockets/vulcan-rocket-launch-in-2019-may-end-u-s-dependence-on-russia-idUSL2N0XA2DE20150414. 5 June 2020. live.
- Web site: Vulcan Centaur Cutaway Poster. United Launch Alliance. November 2019. 14 April 2020. 22 December 2022. https://web.archive.org/web/20221222061600/https://www.ulalaunch.com/docs/default-source/rockets/vulcancentaur.pdf. live.
- Web site: Peller. Mark. United Launch Alliance. 30 March 2016. https://web.archive.org/web/20160412062627/http://www.ispcs.com/content/files/Mark%20Peller.pdf. 12 April 2016. dead.
- Web site: Vulcan. United Launch Alliance. 25 January 2023. 9 May 2022. https://web.archive.org/web/20220509131011/https://www.ulalaunch.com/rockets/vulcan-centaur. live.
- News: Clark. Stephen. ULA selects launch pads for new Vulcan rocket . Spaceflight Now. 12 October 2015. 12 October 2015. https://web.archive.org/web/20151014135112/http://spaceflightnow.com/2015/10/12/ula-selects-launch-pads-for-new-vulcan-rocket/. 14 October 2015. live.
- News: Robinson-Smith . Will . ULA stacks Vulcan rocket for the first time ahead of Jan. 8 debut launch . 22 December 2023 . Spaceflight Now . 21 December 2023 . https://web.archive.org/web/20231222012311/https://spaceflightnow.com/2023/12/21/ula-stacks-vulcan-rocket-for-the-first-time-ahead-of-jan-8-debut-launch/ . 22 December 2023 . live .
- Jan. 8 LIVE Broadcast: Vulcan Cert-1 . en . . 57:11 . 2024-07-11 . YouTube.
- Web site: 2024-01-08 . Vulcan Cert-1 . 2024-07-11 . United Launch Alliance.
- Web site: United Launch Alliance Selects Aerojet Rocketdyne's RL10 Engine. ULA. 11 May 2018. 13 May 2018. https://web.archive.org/web/20180512130637/https://www.ulalaunch.com/about/news/2018/05/11/united-launch-alliance-selects-aerojet-rocketdyne-s-rl10-engine-for-next-generation-vulcan-centaur-upper-stage . 12 May 2018. live.
- Web site: Aerojet Rocketdyne RL10 Propulsion System. Aerojet Rocketdyne. 29 June 2019. https://web.archive.org/web/20190629113839/https://www.rocket.com/sites/default/files/documents/Capabilities/PDFs/RL10_data_sheet.pdf . 29 June 2019. live.
- Web site: As Vulcan nears debut, it's not clear whether ULA will live long and prosper. Ars Technica. Eric Berger. 5 January 2024. 8 January 2024. 6 January 2024. https://web.archive.org/web/20240106084913/https://arstechnica.com/space/2024/01/with-vulcans-liftoff-imminent-united-launch-alliance-flies-into-uncertain-future/. live.
- Web site: Jeff Foust. Vulcan Centaur launches Peregrine lunar lander on inaugural mission. Spacenews. 8 January 2024. 8 January 2024. 8 January 2024. https://web.archive.org/web/20240108153201/https://spacenews.com/vulcan-centaur-launches-peregrine-lunar-lander-on-inaugural-mission/. live.
- Web site: Clark . Stephen . 21 May 2021 . United Launch Alliance nears first fueling test on Vulcan rocket . 8 June 2021 . Space Flight Now.
- Thunnissen . Daniel P. . Guernsey, C. S. . Baker, R. S. . Miyake, R. N. . 2004 . Advanced Space Storable Propellants for Outer Planet Exploration . dead . American Institute of Aeronautics and Astronautics . 4–0799 . 28 . https://web.archive.org/web/20160310001026/https://trs-new.jpl.nasa.gov/dspace/bitstream/2014/37950/1/04-0799.pdf . March 10, 2016.
- Web site: Blue Origin BE-4 Engine . live . https://web.archive.org/web/20211001032523/https://www.blueorigin.com/engines/be-4 . October 1, 2021 . June 14, 2019 . We chose LNG because it is highly efficient, low cost and widely available. Unlike kerosene, LNG can be used to self-pressurize its tank. Known as autogenous repressurization, this eliminates the need for costly and complex systems that draw on Earth’s scarce helium reserves. LNG also possesses clean combustion characteristics even at low throttle, simplifying engine reuse compared to kerosene fuels..
- News: Foust . Jeff . 11 September 2020 . ULA studying long-term upgrades to Vulcan . live . https://web.archive.org/web/20240108153126/https://spacenews.com/ula-studying-long-term-upgrades-to-vulcan/ . 8 January 2024 . 4 March 2021 . "ACES work has its fingerprints in our new version of Centaur, the Centaur 5 we're fielding with Vulcan. Those studies five, eight years ago certainly served us well, and it put us on a good path forward here for the evolution of our upper stages. We will continue to evolve our upper stage to meet the needs of the market going forward"..
- 1145765959593893888 . ToryBruno . Vulcan is configurable with 0 to 6 SRBs. 2 fairing lengths, the longer, 70 ft fairing having a massive 11,000 cuft (317 cu-m) payload volume . 1 July 2019.
- News: Jason Rhian . 23 September 2015 . ULA selects Orbital ATK's GEM 63/63 XL SRBs for Atlas V and Vulcan boosters . live . https://web.archive.org/web/20160111043540/http://www.spaceflightinsider.com/organizations/ula/ula-selects-orbital-atks-gem-6363-xl-srbs-for-atlas-v-and-vulcan-boosters/ . 11 January 2016 . 25 September 2015 . Spaceflight Insider.
- Web site: March 2022 . ULA Rocket Rundown . 27 June 2024 . United Launch Alliance.
- Web site: Atlas V . 10 December 2022 . United Launch Alliance.
- Web site: 4 June 2013 . Delta IV Launch Services User's Guide – June 2013 . https://web.archive.org/web/20131014123330/http://www.ulalaunch.com/site/docs/product_cards/guides/Delta%20IV%20Users%20Guide%20June%202013.pdf . 14 October 2013 . 31 October 2020 . United Launch Alliance . 2–10,5-3.
- 770579558726668288 . torybruno . @A_M_Swallow @ULA_ACES We intend to human rate Vulcan/ACES . Tory . Bruno . August 30, 2016.
- Web site: Shalal . Andrea . 21 May 2015 . Lockheed-Boeing rocket venture needs commercial orders to survive . dead . https://web.archive.org/web/20150723052732/https://news.yahoo.com/lockheed-boeing-rocket-venture-needs-commercial-orders-survive-205416832--finance.html . 2015-07-23 . Yahoo! News.
- News: Avery . Greg . 2014-10-16 . ULA plans new rocket, restructuring to cut launch costs in half . live . https://web.archive.org/web/20170315142232/http://www.bizjournals.com/denver/blog/boosters_bits/2014/10/exclusive-ula-plans-a-new-rocket-restructuring-to.html . 2017-03-15 . 2014-11-14 . Denver Business Journal.
- News: Erwin . Sandra . 19 August 2021 . National security launch in transition as Space Force waits for Vulcan . 16 June 2024 . Space News.
- News: Ferster . Warren . ULA To Invest in Blue Origin Engine as RD-180 Replacement . SpaceNews . 17 April 2015 . https://archive.today/20140918114236/http://www.spacenews.com/article/launch-report/41901ula-to-invest-in-blue-origin-engine-as-rd-180-replacement . dead . 18 September 2014 . 17 September 2014 .
- News: Fleischauer . Eric . ULA's CEO talks challenges, engine plant plans for Decatur . Decatur Daily . 7 February 2015 . 17 April 2015 . https://web.archive.org/web/20170612024028/http://www.decaturdaily.com/news/ula-s-ceo-talks-challenges-engine-plant-plans-for-decatur/article_8ba49046-af4a-11e4-97ef-ff58591d43fc.html . 12 June 2017 . live.
- News: Gruss. Mike . ULA's Vulcan Rocket To be Rolled out in Stages. SpaceNews. 13 April 2015. 17 April 2015.
- News: Ray . Justin . ULA chief explains reusability and innovation of new rocket. Spaceflight Now. 14 April 2015. 17 April 2015. https://web.archive.org/web/20150417032046/http://spaceflightnow.com/2015/04/14/ula-chief-explains-reusability-and-innovation-of-new-rocket/. 17 April 2015. live.
- News: Gruss. Mike. ULA's parent companies still support Vulcan ... with caution. SpaceNews. 10 March 2016. 10 March 2016. 8 January 2024. https://web.archive.org/web/20240108152603/https://spacenews.com/ulas-parent-companies-still-support-vulcan-with-caution/. live.
- News: Air Force awards launch vehicle development contracts to Blue Origin, Northrop Grumman, ULA. Erwin. Sandra. 10 October 2018. SpaceNews. 28 July 2020. 11 October 2018. https://archive.today/20181011074001/https://spacenews.com/air-force-awards-launch-vehicle-development-contracts-to-blue-origin-northrop-grumman-ula/. live.
- News: Boeing, Lockheed Differ on Whether to Sell Rocket Joint Venture. THE Wall Street Journal. 10 September 2015. 12 September 2015. https://web.archive.org/web/20170415201056/https://www.wsj.com/articles/boeing-lockheed-differ-on-whether-to-sell-rocket-joint-venture-1441933638. 15 April 2017. live.
- News: de Selding. Peter B.. ULA intends to lower its costs, and raise its cool, to compete with SpaceX. SpaceNews. 16 March 2016. 19 March 2016. Methane rocket has a lower density so we have a 5.4 meter design outside diameter, while drop back to the Atlas V size for the kerosene AR1 version.. 17 March 2016. https://archive.today/20160317125310/http://spacenews.com/ula-intends-to-lower-its-costs-and-raise-its-cool-to-compete-with-spacex/. live.
- News: Erwin. Sandra. Air Force stakes future on privately funded launch vehicles. Will the gamble pay off?. SpaceNews. 25 March 2018. 24 June 2018. https://web.archive.org/web/20150821031330/http://tools.wmflabs.org/makeref/. 21 August 2015. live.
- Web site: Tribou. Richard. ULA chooses Aerojet Rocketdyne over Blue Origin for Vulcan's upper stage engine. Orlando Sentinel. 11 May 2018 . 13 May 2018. https://web.archive.org/web/20180513060411/http://www.orlandosentinel.com/news/space/go-for-launch/os-united-launch-alliance-rocket-aerodyne-vulcan-20180511-story.html . 13 May 2018. live.
- United Launch Alliance Building Rocket of the Future with Industry-Leading Strategic Partnerships – ULA Selects Blue Origin Advanced Booster Engine for Vulcan Centaur Rocket System. United Launch Alliance. 27 September 2018 . 5 October 2018. https://web.archive.org/web/20181006075150/https://www.ulalaunch.com/about/news/2018/09/27/united-launch-alliance-building-rocket-of-the-future-with-industry-leading-strategic-partnerships. 6 October 2018. live.
- News: Jeff Bezos' Blue Origin to supply engines for Vulcan rocket. Reuters. Eric M.. Johnson. Joey. Roulette. 27 September 2018. 28 September 2018 . https://web.archive.org/web/20180928044934/https://www.reuters.com/article/us-blue-origin-ula/jeff-bezos-blue-origin-to-supply-engines-for-vulcan-rocket-idUSKCN1M70UM. 28 September 2018. live.
- News: ULA now planning first launch of Vulcan in 2021. SpaceNews. Jeff. Foust. 25 October 2018. 11 November 2018. 8 January 2024. https://web.archive.org/web/20240108152604/https://spacenews.com/ula-now-planning-first-launch-of-vulcan-in-2021/. live.
- jeff_foust. 954054070821670912. Tom Tshudy, ULA: with Vulcan we plan to maintain reliability and on-time performance of our existing rockets, but at a very affordable price. First launch mid-2020.. 18 January 2018.
- News: Foust. Jeff. ULA now planning first launch of Vulcan in 2021. Space News. 25 October 2018. 28 January 2023. 8 January 2024. https://web.archive.org/web/20240108152604/https://spacenews.com/ula-now-planning-first-launch-of-vulcan-in-2021/. live.
- ToryBruno. 1158856939532505088. 6 August 2019. Mighty Atlas is not the only thing rolling at the Cape today. Check the new Vulcan MLP arrival..
- ULAlaunch. 1158865233173237761. 6 August 2019 . The MLP will transport #VulcanCentaur Vertical Integration Facility to SLC-41 using heritage undercarriage dollies used for Titan III, Titan IV and #AtlasV and will move at 3 mph. #VulcanCentaur.
- Web site: 4 February 2021 . Three rockets depart factory aboard RocketShip . live . https://web.archive.org/web/20210205103445/https://www.ulalaunch.com/explore/blog-detail/blog/2021/02/04/three-rockets-depart-factory-aboard-rocketship . 5 February 2021 . 6 February 2021 . United Launch Alliance.
- Web site: Vulcan: Pathfinder fueling tests planned . live . https://web.archive.org/web/20220407062657/https://blog.ulalaunch.com/blog/vulcan-centaur-pathfinder-fueling-tests-planned . 7 April 2022 . 11 April 2022 . blog.ulalaunch.com.
- Web site: Vulcan: First demonstration of launch day completed . live . https://web.archive.org/web/20220414190345/https://blog.ulalaunch.com/blog/vulcan-centaur-first-demonstration-of-launch-day-completed . 14 April 2022 . 24 April 2022 . blog.ulalaunch.com.
- News: Chow . Denise . 4 February 2023 . Bigger, faster, farther: A batch of new rockets is set to blast into space this year . live . https://web.archive.org/web/20230204183708/https://www.nbcnews.com/science/space/bigger-faster-farther-batch-new-rockets-set-blast-space-year-rcna65014 . 4 February 2023 . 14 February 2023 . NBC News.
- Web site: 19 August 2019 . Astrobotic Selects United Launch Alliance Vulcan Centaur Rocket to Launch its First Mission to the Moon . live . https://web.archive.org/web/20190819204709/https://www.ulalaunch.com/about/news/2019/08/19/astrobotic-selects-united-launch-alliance-vulcan-centaur-rocket-to-launch-its-first-mission-to-the-moon . 19 August 2019 . 19 August 2019 . ULA Launch.
- Web site: Neal. Mihir. Vulcan on track as ULA eyes early – 2021 test flight to the Moon. 8 June 2020. 9 June 2020. https://web.archive.org/web/20200609190037/https://www.nasaspaceflight.com/2020/06/vulcan-2021-moon-flight/. 9 June 2020. live.
- https://www.reuters.com/article/us-space-exploration-blueorigin/bezos-blue-origin-to-deliver-first-flight-ready-rocket-engines-next-summer-ula-ceo-idUSKBN28S0I8 Bezos' Blue Origin to deliver first flight-ready rocket engines next summer
- Weapon Systems Annual Assessment . 8 June 2021 . US Government Accountability Office (GAO) . 106 . GAO-21-222 . ...a U.S. produced rocket engine under development for ULA's Vulcan launch vehicle is experiencing technical challenges related to the igniter and booster capabilities required and may not be qualified in time to support first launches beginning in 2021. . 23 June 2021 . https://web.archive.org/web/20210624201648/https://www.gao.gov/assets/gao-21-222.pdf#page116 . 24 June 2021 . live.
- 1405701313040732161 . Free_Space . Debut launch of @ulalaunch Vulcan slipping to 2022 as customer @astrobotic needs more time to prep Peregrine lunar lander. "Covid presented a lot of problems for the entire space supply chain," CEO John Thornton tells @aviationweek "We're just doing the best we can." . Irene Klotz.
- News: Kanayama . Lee . As Centaur turns 60 years old, ULA prepares to evolve Centaur V . . 9 May 2022 . 29 May 2022 . 1 August 2023 . https://web.archive.org/web/20230801020510/https://www.nasaspaceflight.com/2022/05/centaur-turns-60/ . live .
- News: Roulette . Joey . 10 October 2022 . United Launch Alliance's debut Vulcan mission slips to 2023 -CEO . live . https://web.archive.org/web/20221010221557/https://www.reuters.com/lifestyle/science/united-launch-alliances-debut-vulcan-mission-slips-2023-ceo-2022-10-10/ . 10 October 2022 . 11 October 2022 . Reuters.
- Web site: First Vulcan launch further delayed for Centaur modifications. Jeff. Foust. 24 June 2023. 24 June 2023. Spacenews. 8 January 2024. https://web.archive.org/web/20240108152617/https://spacenews.com/first-vulcan-launch-further-delayed-for-centaur-modifications/. live.
- Web site: Foust . Jeff . 2023-10-24 . ULA sets Christmas Eve launch date for first Vulcan Centaur . 2023-10-24 . . 8 January 2024 . https://web.archive.org/web/20240108152601/https://spacenews.com/ula-sets-christmas-eve-launch-date-for-first-vulcan-centaur/ . live .
- Web site: McCrea . Aaron . Vulcan successfully launches Peregrine lunar lander on inaugural flight . 8 January 2024 . 8 January 2024 . NASASpaceFlight . 8 January 2024 . https://web.archive.org/web/20240108153003/https://www.nasaspaceflight.com/2024/01/vulcan-launch-peregrine-inaugural-flight/ . live .
- Web site: Update #8 for Peregrine Mission One. Astrobotic. 9 January 2024. 12 January 2024. 12 January 2024. https://web.archive.org/web/20240112151659/https://www.astrobotic.com/update-8-for-peregrine-mission-one/. live.
- Web site: SNC Selects ULA for Dream Chaser® Spacecraft Launches: NASA Missions to Begin in 2021. 14 August 2019. ULA Launch. 14 August 2019. https://web.archive.org/web/20190814190202/https://www.ulalaunch.com/about/news/2019/08/14/snc-selects-ula-for-dream-chaser-spacecraft-launches. 14 August 2019. live.
- Web site: ULA Sets Dec. 24 As Target Date For Vulcan's Debut . 2024-01-11 . Aviation Week Network (aviationweek.com) . 28 December 2023 . https://web.archive.org/web/20231228155038/https://aviationweek.com/aerospace/commercial-space/ula-sets-dec-24-target-date-vulcans-debut . live .
- Web site: Vulcan on the pad for its first launch. Spacenews. Jeff Foust. 5 January 2024. 8 January 2024.
- Web site: Contracts for August 7, 2020 . live . https://web.archive.org/web/20200920110521/https://www.defense.gov/Newsroom/Contracts/Contract/Article/2305454/ . 20 September 2020 . 9 August 2020 . U.S. DEPARTMENT OF DEFENSE.
- News: With ULA's new rocket Vulcan behind schedule, Space Force agrees to let Atlas 5 fill in . Erwin . Sandra . SpaceNews . 20 May 2021 . 22 May 2021 . 8 January 2024 . https://web.archive.org/web/20240108153127/https://spacenews.com/with-ulas-new-rocket-vulcan-behind-schedule-space-force-agrees-to-let-atlas-5-fill-in/ . live .
- News: Clark . Stephen . 7 August 2023 . Amazon shifts launch of its first Internet satellites to Atlas V rocket . live . https://web.archive.org/web/20230807164939/https://arstechnica.com/space/2023/08/amazons-first-internet-satellites-will-launch-on-atlas-v-rocket-not-vulcan/ . 7 August 2023 . 7 August 2023 . Ars Technica.
- Web site: Erwin . Sandra . 2024-05-13 . ULA could fly dummy payload on next Vulcan launch if Dream Chaser is delayed . 2024-05-14 . SpaceNews . en-US.
- Web site: Lockheed-Boeing Alliance Hit With US Fine for Launch Delays . 2024-05-15 . www.bloomberg.com.
- News: Davenport . Christian . 2024-05-13 . Pentagon worried its primary satellite launcher can’t keep pace . 2024-06-28 . Washington Post . en-US . 0190-8286.
- Web site: Decker . Audrey . 2024-06-26 . ULA owners add ‘review team’ after Pentagon airs concerns about launch schedule . 2024-06-28 . Defense One . en.
- Web site: Vulcan Centaur . live . https://web.archive.org/web/20210225185355/https://www.ulalaunch.com/rockets/vulcan-centaur . 25 February 2021 . 3 March 2021 . ulalaunch.com.
- Web site: Vulcan Centaur Cutaway Poster . live . https://web.archive.org/web/20221222061600/https://www.ulalaunch.com/docs/default-source/rockets/vulcancentaur.pdf . 22 December 2022 . 25 September 2019 . ULA.
- Web site: October 2023 . Vulcan Launch Systems User's Guide . live . https://web.archive.org/web/20240416234106/https://www.ulalaunch.com/docs/default-source/rockets/2023_vulcan_user_guide.pdf . 16 April 2024.
- Web site: Space and Missile Systems . 5 October 2018 . EELV LSA RFP OTA . dead . https://web.archive.org/web/20190203062442/https://www.fbo.gov/utils/view?id=e2c583b4a02911ba7f59eff384b38664 . 3 February 2019 . 22 June 2019 . table 10 of page 27.
- News: Foust . Jeff . 11 September 2020 . ULA studying long-term upgrades to Vulcan . live . https://web.archive.org/web/20240108153126/https://spacenews.com/ula-studying-long-term-upgrades-to-vulcan/ . 8 January 2024 . 7 July 2021 . Space News.
- News: Henry . Caleb . 20 November 2019 . ULA gets vague on Vulcan upgrade timeline . live . https://web.archive.org/web/20240108152615/https://spacenews.com/ula-gets-vague-on-vulcan-upgrade-timeline/ . 8 January 2024 . 20 June 2020 . SpaceNews.
- Web site: 13 April 2015 . America, meet Vulcan, your next United Launch Alliance rocket . live . https://web.archive.org/web/20150417171804/http://www.denverpost.com/business/ci_27905093/america-meet-vulcan-your-next-united-launch-alliance . 17 April 2015 . 17 April 2015 . Denver Post.
- News: Erwin . Sandra . 7 April 2021 . Bruno: The next big thing for ULA is a long-endurance upper stage . live . https://web.archive.org/web/20240108153037/https://spacenews.com/bruno-the-next-big-thing-for-ula-is-a-long-endurance-upper-stage/ . 8 January 2024 . 7 July 2021 . Space News.
- News: Klotz . Irene . 20 July 2022 . ULA Refines Plan To Reuse Vulcan Rocket Engines . live . https://web.archive.org/web/20220721013617/https://aviationweek.com/defense-space/budget-policy-operations/ula-refines-plan-reuse-vulcan-rocket-engines . 21 July 2022 . 21 July 2022 . Aviation Week.
- Web site: The Space Review: A megaconstellation megadeal . live . https://web.archive.org/web/20220414180623/https://www.thespacereview.com/article/4367/1 . 14 April 2022 . 8 June 2022 . www.thespacereview.com.
- 1285290783931858944 . torybruno . By demand of the Internet, here is the uncropped picture of the #MarsPerseverance flip flops. Just a model. Related to a routine, ongoing trade study. Nothing more. . Tory . Bruno.
- Web site: Foust . Jeff . 11 September 2020 . ULA studying long-term upgrades to Vulcan . live . https://web.archive.org/web/20240108153126/https://spacenews.com/ula-studying-long-term-upgrades-to-vulcan/ . 8 January 2024 . 30 September 2020 . SpaceNews.