Space Launch Report:  Vulcan Data Sheet
Home    On the Pad     Space Logs     Library    Links
Vulcan-441.jpg (4158 bytes)Vulcan

Vehicle Configurations

Vehicle Components

NGLV Launch Record

Vulcan Centaur as Illustrated on April 13, 2015


ULA Announces Vulcan

At the 31st Space Symposium on April 13, 2015 , United Launch Alliance (ULA) announced that its Next Generation Launch System (NGLS) would be named "Vulcan", after the Roman god of fire.  The company also revealed plans for a step-by-step Vulcan development process that would keep some existing EELV elements in service for years.

During the first step, a new booster stage will replace the existing Atlas 5 Common Core Booster (CCB).  The new 5.4 meter diameter booster will be powered, as previously announced, by two Blue Origin BE-4 LOX/LNG engines.  It will lift existing Centaur stages and existing four or five meter diameter payload fairings.   As many as four solid rocket boosters (SRBs) can be added to augment the four meter rocket, while up six SRBs can boost the five meter rocket.  The solids will also be offered for competitive bidding, but are expected to be similar to the existing Aerojet Atlas 5 solids.  

With six SRBs and a Centaur within a 5.4 meter fairing, Vulcan would lift more payload than Atlas 5-551, but less than Delta 4 Heavy. 

During the second step, the Centaur second stage will be replaced by a heavier and more powerful stage named Advanced Cryogenic Evolved Stage (ACES).  ACES will carry three times more LH2/LOX propellant than Centaur and will produce more thrust than Centaur.   ACES will also feature an "Integrated Vehicle Fluids" system that will use existing propellant boil-off gases for thrusting, pressurization, and electricity generation, eliminating or reducing hydrazine and helium systems and batteries.   Another competition will be held to determine which engine or engines will power ACES.  Contenders include RL10,  Blue Origin's BE-3U, and an XCOR engine.   With six SRBs and ACES, Vulcan will be able to outlift the existing Delta 4 Heavy.

A tri-core "Vulcan Heavy" topped by an ACES could conceivably lift an impressive 22.6 tonnes to geosynchronous transfer orbit - 1.6 times more than Delta 4 Heavy -  but development of such a heavy-lifter is unlikely.

ULA will consider recovery of the BE-4 engines, using a heat shield, a parachute, and helicopter air recovery.

ULA's existing Delta 4 Medium will be phased out beginning in 2018, as Vulcan with Centaur begins to fly.  Delta 4 Heavy will be phased out later, likely when ACES begins to fly in 2023.  When Delta 4 Heavy stops flying, one launch pad on each coast will be retired.  Retiring Delta 4 will free up 5 meter tank tooling for Vulcan.  

be4.jpg (17594 bytes)ULA/Blue Origin to Develop Powerful New Engine (September 17, 2014)

BE-4 Model at Press Conference

On September 17, 2014, United Launch Alliance and Blue Origin, a privately held company owned by founder Jeff Bezos, announced that they were teaming to jointly fund development of Blue Origin's new BE-4 rocket engine. The development effort would last four years, with full-scale testing in 2016 and first flight in 2019. The new engine would be available for use by both companies.

BE-4 will burn liquid oxygen and liquefied natural gas (LNG) in an oxygen rich staged combustion cycle to produce 550,000 pounds (249.5 tonnes) of sea level thrust. ULA boosters would use two BE-4s to produce 1,100,000 pounds (499 tonnes) of total thrust at sea level.

Blue Origin has been working on BE-4 development for three years, with component testing underway at the company's test site near Van Horn, Texas and in facilities near Kent, Washington. Completed testing has included subscale oxygen-rich preburner development and staged combustion testing of the preburner and main injector assembly. Testing of the turbopumps and main valves is the next major step. A large new test facility was completed in May, 2014 in Texas to support full-scale engine testing.

BE-4 will likely operate at a specific impulse comparable to the Atlas 5 RD-180, but not as high as Delta 4's RS-68. The engine could be heavier than RD-180, and the less dense propellant would force use of bigger, heavier tanks than those used by Atlas 5, but BE-4s higher thrust compared to RD-180 would help offset those factors.

ULA noted that BE-4 is not a direct replacement for RD-180, but that "two BE-4s are expected to provide the engine thrust for the next generation ULA vehicles". The company said that the "next generation vehicles" would "maintain the key heritage components of ULA’s Atlas and Delta rockets", including the strap-on solid boosters, and said that details would be announced at a later date.

NGLSs.jpg (10617 bytes)Potential NGLS Appearance (Unofficial Estimates)

The phrase "Next Generation Launch System" (NGLS) has been linked with ULA's BE-4 powered design.  The company was expected to reveal details of NGLS during 2015.

NGLS is likely to be designed to use existing launch pads, upper stages, and payload fairings to the greatest extent possible.  Since LNG is less dense than kerosene, one possibility is that ULA will use Delta 4 Common Booster Core 5.1 meter diameter tanks for the BE-4 powered first stage.  This would allow the first stage to be the same height as the Atlas 5 Common Core Booster first stage, which is about 4.2 meters shorter than the Delta 4 CBC.  Since two BE-4 engines would produce a bit more thrust than a single RD-180 engine at liftoff, the NGLS first stage would likely weigh an equivalant amount more than the Atlas 5 first stage.

At liftoff, the NGLS first stage thrust could be augmented in some vehicle variants by solid rocket motors (SRBs) similar to those that power Atlas 5.  At 1.55 x 17.7 meters and weighing more than 46 tonnes loaded, the composite case, single-segment  Atlas 5 motors produce 172 tonnes of thrust at liftoff.  ULA may want to increase the number of SRBs beyond the maximum of five used by Atlas 5 to provide a variant capable of replacing Delta 4 Heavy.  This NGLS Heavy would require a new, or upgraded, upper stage, but once developed would be able to perform EELV Heavy missions using a single-core vehicle.   

For NGLS, ULA is likely to initially continue use of the Atlas 5 Centaur, the descendant of the world's first liquid hydrogen/oxygen upper stage.   Centaur uses stainless steel balloon tanks, with the lower LOX and upper LH2 tanks separated by a common elliptical bulkhead. The Atlas 5 Centaur is transitioning from its original restartable Pratt & Whitney RL10A-4-2 engine to an updated Aerojet Rocketdyne RL10C-1 engine.  Both use a fixed carbon-carbon composite nozzle extension. RL10C-1 produces 10.383 tonnes of thrust at about 450 seconds ISP, compared to RL10A-4-2 thrust of 10.12 tonnes of thrust at 450.5 seconds ISP.

ULA will likely want to replace the RL10C-1 engines at some point in the future with a new, more efficient 15 tonne thrust class engine.

Thin-skinned Centaur cannot easily support the 5.4 meter diameter payload fairing, so the existing Atlas 5 setup that uses a Contraves 5.4-meter diameter composite fairing to enclose Centaur and transfer the payload fairing mass to the first stage will likely be used.  This approach was originally used for the Centaur stages on Titan 3E and Titan 4.  The fairing itself was derived from Ariane 5 designs.

ULA currently launches Atlas 5 from Cape Canaveral Space Launch Complex (SLC) 41 and Vandenberg AFB SLC 3 East.  It also launches Delta 4 from Cape Canaveral SLC 37B and Vandenberg AFB SLC 6.  At the Cape, Atlas V is assembled in a new 85.4 meter tall Vertical Integration Facility (VIF) and transported 550 meters on a mobile launch platform to the pad no more than 24 hours before liftoff.  The Vandenberg pad uses a conventional mobile service tower, rather than a "clean pad". 

The company will want to consolidate these costly launch support facilities for NGLS.  If a single-core NGLS can be designed to perform a range of missions from EELV Medium to EELV Heavy, it should be possible to retire Delta 4, allowing the company to abandon SLC 6 and SLC 37B.  NGLS could then fly from updated SLC 41 and SLC 3 East.  In this scenario, NGLS will also replace Atlas 5, allowing ULA to end use of Russian-made engines. 

September-October 2015 Developments

During September 2015, ULA announced that it had rejected a $2 billion take-over bid by Aerojet-Rocketdyne.  The company also announced that it would expand co-production capacity for Blue Origin's BE-4 engine.   Finally, ULA announced that it had selected Orbital ATK to produce solid motors for both Vulcan and for Atlas 5 beginning before the end of 2018. 

The new GEM-63 (63 inch diameter) motors would generally replicate the dimensions and performance of the existing Aerojet Rocketdyne AJ-60A motors used by Atlas.  GEM-63XL motors, stretched about 1.52 meters compared to the GEM-63 motors, will power Vulcan.  The stretched motors would likely carry 5-10% more propellant and provide about 5-10% more thrust compared to GEM-63. 

The announcement further reduces Aerojet Rocketdyne's ULA work.  Vulcan will end use of RD-180, RS-68A, and AJ-60A, leaving only the RL-10 upper stage motor.  The upper stage motor will likely be competed when the stage is upgraded.

During October, ULA announced that Vulcan would fly from the two existing Atlas 5 launch sites, SLC 41 at Cape Canaveral, Florida and SLC 3E at Vandeberg AFB, California.  Both pads would be modified to handle Vulcan, but the modifications would not interrupt Atlas operations, which would continue flying for several years into the 2020s.  Modifications would include the installation of liquified natural gas equipment.  The Vulcan maiden flight was expected to occur during 2019.  The existing Delta 4 pads would remain in service until the ACES stage was developed for Vulcan, perhaps as soon as 2023, several years after the new rocket initially began flying with Centaur.  The final Delta 4 Medium flight would take place in 2019, but Delta Heavy would keep flying until the Vulcan/ACES heavy version had proved itself in flight.

ULA was planning for one of  two possible Vulcan first stage designs.  A 2 x BE-4 powered version would be at least 5.08 meters (200 inches) in diameter.   Some hints suggested that the diameter could grow to as much as 5.4 meters, the same as the payload fairing.  A 2 x AR-1 version would be 3.81 meters (150 inches) in diameter, the same as the Atlas 5 CCB.   ULA's primary plan remained BE-4, with AR-1 as a backup.  The final engine decision was expected to be made before 2016.

BE-4-1.jpg (29491 bytes)April 2017 Updates

First BE-4 Rolls Out at Blue Origin during March, 2017

During mid-April, 2017, ULA President and CEO Tony Bruno confirmed that Vulcan would use 5.4 meter diameter tanks.  The new tanks, fatter than even the Delta 4 tanks, would be fabricated by friction stir welding four orthogrid panels together.  Use of the orthogrid design, replacing the previous isogrid, will play a role in reducing production time by half. 

Earlier in the same month, Bruno had confirmed that a final propulsion decision between BE-4 and AR-1 would be made by the end of 2017.  At the time, BE-4 was expected to begin full-scale testing within a few weeks.  The results of that testing would inform ULA's decision.

Blue Origin had rolled-out its first BE-4 engine during March, 2017.  The engine was delivered to the company's Texas test site for full-scale testing.


Vehicle Configurations (Estimated based on 2016 ULA Paper)

(metric tons)
(185 km x
28.5 deg)(1)
(metric tons)
(407 km x
51.6 deg)
(metric tons)
(200 km x
28.5 deg) (1)
90.0 deg) (2)
GTO Payload
1500 m/s to
GTO Payload
1800 m/s to
GEO Payload
(metric tons)
Configuration LIftoff Height
Liftoff Mass
(metric tons)
Vulcan Centaur (est) up to 20+ t       5.35-10.25 t (0-6 SRB)   Core + 0-6 SRB +
58.3 m 432-667 t
Vulcan ACES (est) up to 40+ t       8.61-17.23 t (0-6 SRB)   Core + 0-6 SRB +
62.2 m up to 781 t

* GEO: Geosynchronous Earth Orbit

Vehicle Components (NGLS Building Blocks)

First Stage
Single (SEC)
ACES 400
Diameter (m) 1.55 m 5.1 m (est) 3.05 m 5.1 m 3.85/3.05 m 3.83 m
Length (m) 19.224 m 32.46 m (est) 12.68 m - 4.78 m 4.31 m
Usable Propellant Mass (tonnes) ~46.3 t (est) ~368 t 20.8 t 68 t    
Total Mass (tonnes) ~50.24 t (est) ~400 t 22.83 t ~74.7 t 0.8 t 1.57 t
Engine GEM-63XL BE-4 RL-10C-1 -    
Engine Manufacturer Aerojet Blue Origin Aerojet Rocketdyne -    
Fuel HTPB LNG LH2 LH2    
Oxidizer HTPB LOX LOX LOX    
Thrust (sea level, tonnes) ~187 t (est) 499 t   -    
Thrust (vac (avg) tonnes) ~138 t (est) ~540 t (est) 10.383 t ~44 t    
ISP (sea level, sec) 245 s ~310 s   -    
ISP (vac sec) 275 s ~335 s ~450 s ~460    
Burn Time (sec) 90 s ~240 s ~835 s (SEC) -    
No. Engines 1 2 1 1-4    

Vehicle Components, Cont'd (Atlas 5 Fairings Shown, Vulcan Details TBD)

  400 Large Fairing 400 Extended Fairing 5 m Short Fairing 5 m Long Fairing  
Diameter (meters) 4.2 m 4.2 m 5.4 m 5.4 m  
Length (meters) 12.2 m 13.1 m 20.7 m 23.4 m  
Mass (tons) 2.09 t 2.26 t 4.09 t 4.65 t  

Vulcan Launch Record

 Date    Vehicle      ID    Payload              Mass Site*   Orbit            Orbit
                                                 kg          (kmxkmxdeg)       Type**
NN/NN/NN NGLs         NNNNN NNNNN                NNNN  CC41  NNNxNNNNNxNN.NN   AAA


*Site Code:

CC = Cape Canaveral, FL, USA
CC37B = Space Launch Complex 37B: Delta 4 
CC41 = Space Launch Complex 41: Atlas 5

VA = Vandenberg AFB, CA, USA
VA3E = Space Launch Complex 3E: Atlas 5
VA6 = Space Launch Complex 6: Delta 4

**Orbit Code:


Atlas Launch Systems Mission Planners Guide, Atlas V Addendum, January 1999
Atlas Launch Systems Mission Planners Guide, Rev 9, September 2001
Atlas Launch Systems Mission Planners Guide, Rev 10, December 2004
Atlas V and Delta IV Technical Summary, ULA, June 2013
BE-4 Fact Sheet, Blue Origin, September 2014
BE-4 Announcement, ULA/Blue Origin, September 2014
Tony Bruno Twitter Post, July, 2015
Vulcan, ACES, and Beyond, ULA, 2016

 Last Update: June 09, 2017