Atlas 5

Vehicle Configurations

Vehicle Components

Atlas 5 Launch Record

Atlas 5 was Lockheed Martin's Evolved Expendable Launch Vehicle (EELV) design for the U.S. Air Force. The United Launch Alliance consortium, a new company spun off by Boeing and Lockheed Martin, took over the Delta IV and Atlas V EELV programs in December 2006.

The rocket, available in several variants, is built around a LOX/RP-1 Common Core Booster (CCB) first stage and a LOX/LH2 Centaur second stage powered by one or two RL10 engines. Up to five solid rocket boosters (SRBs) can augment first stage thrust.  

A three-digit designator identifies Atlas V configurations. The first digit signifies the vehicle's payload fairing diameter in meters. The second digit tells the number of SRBs. The third digit provides the number of Centaur second stage RL10 engines (1 or 2).

The Atlas V 400 series, with a 4 meter payload fairing and up to three SRBs, can boost up to 7.7 metric tons to a 28.7 deg geosynchronous transfer orbit (GTO) or 15.26 tonnes to a 28.7 deg low earth orbit (LEO) from Cape Canaveral. Atlas V 500, with a 5 meter diameter payload fairing and up to five SRBs, can put up to 8.9 tonnes to a 28.7 deg GTO or 18.85 tonnes into a 28.7 deg LEO. A 2.5 stage, Atlas 5 Heavy that uses three parallel burn CCBs, has been designed but not developed.  Higher payloads to LEO are possible if two RL-10 engines are used, but that variant had not been developed as of mid-2013.  

CCB replaces heritage Atlas stainless steel balloon tanks with aluminum isogrid tanks. A single dual thrust chamber RD-180 engine, made by Russia's NPO Energomash, powers the stage. RD-180 was derived from four-chamber RD-170, an engine initially developed for the Soviet's Energia strap on boosters and now used by Zenit launch vehicles. The throttable engine uses a staged combustion cycle, with low pressure turbopumps feeding propellant to a high pressure turbopump. Propellant pressure is further increased through use of a preburner.

At liftoff, CCB thrust can be augmented by up to five Aerojet solid rocket motors (SRBs). At 1.55 x 17.7 meters, the motors are currently the world's largest single-segment solid.

For Atlas V, Centaur, the world's first liquid hydrogen/oxygen upper stage, was stretched and upgraded. The stage still uses stainless steel balloon tanks, with the lower LOX and upper LH2 tanks separated by a common elliptical bulkhead. Centaur is powered by a restartable Pratt & Whitney RL10A-4-2 engine with a fixed carbon-carbon composite nozzle extension.

Thin-skinned Centaur cannot support the heavier 500-series payloads, so a Contraves 5-meter diameter composite fairing is used to transfer payload weight to CCB by enclosing Centaur. This approach was originally used for Titan 3E and Titan 4. The fairing was derived from Ariane 5 designs.

Atlas 5 launches from Cape Canaveral Space Launch Complex (SLC) 41, a rebuilt Titan 4 pad.  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. 

On March 13, 2006, AV-006 performed the first West Coast Atlas 5 launch from a rebuilt pad at Vandenberg AFB SLC 3 East.  The Vandenberg pad uses a conventional mobile service tower, rather than a "clean pad".

As of mid-2013, ULA had tasked Pratt & Whitney (by then part of the new Aerojet-Rocketdyne company) with converting excess RL10B-2 engines built for Delta IV into RL-10C-1 engines for Atlas V.  These engines will dispense with the two extendible nozzle sections, leaving only a single fixed carbon composite exension.   The change will result in an engine that produces more thrust than RL10-A-4-2 but that likely produces slightly less specific impulse.  Overall, the change will improve Atlas V performance slightly for heavier payloads, but lessen performance for lighter payloads.  The modified engines will gradually supplant the original engines, with inventories of both types running out in 2018 or later.  At that point, either a new 15 tonne thrust class engine will be developed or new RL10 engines will be purchased.

Atlas 5 Launches NRO Mission

The most powerful Atlas 5 to fly from Vandenberg AFB, a 541 model with four solid rocket motors and a five meter diameter payload fairing, launched the classified National Reconnaissance Office NROL-35 mission on December 13, 2014. The 522 tonne rocket lifted off from Space Launch Complex 3 East at 03:19 UTC and quickly flew into a news blackout.

Analysts expected the launch to orbit a payload bound for an elliptical 12-hour Molniya type orbit. Potential payloads included communications or signals intelligence satellites. The use of an Atlas 541 indicated that the satellite would likely be heavier than any previously launched by the U.S. to a Molniya orbit. A previous launch of a "Trumpet"-type sigint to 1,120 x 37,600 km x 63.56 deg Molniya orbit used a less-capable Atlas 5-411 with only one strap-on solid motor.

The AV-051 Atlas was the first equipped with an RL10C-1 Centaur engine. The Aerojet-Rocketdyne powerplant was a modified RL10B-2 that came from excess stock from the Delta 4 program. To make the conversion, the bottom two extendible nozzle sections of the RL10B-2 were removed and an improved dual direct spark igniter was installed. The engine produced 10.383 tonnes of thrust, a slight improvement from 10.115 tonnes of thrust produced by the previous RL10A-4-2 Centaur engine.

It was the 455th RL10 launched. The engines have flown for 50 years on seven different launch vehicle types, including Saturn I, Atlas Centaur, Atlas 3, Atlas 5, Titan 3E, Titan 4A/B, and Delta 3.

AV-051 was ninth Atlas 5 of the year, a record for Atlas 5. It was also the third Atlas 5 of the year to fly from VAFB.

Vehicle Configurations

# Using Dual Engine Centaur
## Using Single Engine Centaur
* GEO: Geosynchronous Earth Orbit
Shaded Models to be Phased Out as RL-10C-1 Enters Service


Vehicle Components

Vehicle Components, Cont'd

Atlas 5 Launch Record

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 Date    Vehicle      ID    Payload              Mass Site*   Orbit            Orbit
                                                 kg          (kmxkmxdeg)       Type**
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08/21/02 Atlas 5-401  AV001 Hot Bird 6           3905  CC41  315x45863x17.82    GTO+
05/13/03 Atlas 5-401  AV002 HellaSat 2           3440  CC41  312x85457x17       GTO+
07/17/03 Atlas 5-521  AV003 Rainbow 1            4328  CC41  3790x35845x17.5    GTO+
12/17/04 Atlas 5-521  AV005 AMC-16               4200  CC41  4761x34611x27.2    GTO
03/11/05 Atlas 5-431  AV004 Inmarsat 4F1 (4A)    5945  CC41  440x90500x21       GTO+ 
08/12/05 Atlas 5-401  AV007 MRO Mars Orbiter     2180  CC41                     HCO
01/19/06 Atlas 5-551  AV010 Pluto New Horizons    478  CC41                     HCO
04/20/06 Atlas 5-411  AV008 Astra 1KR            4332  CC41  6212x37786x23.97   GTO+
03/09/07 Atlas 5-401  AV013 STP-1 (OES+)         1400  CC41  560x560x35.4       LEO
06/15/07 Atlas 5-401  AV009 NROL-30R                   CC41 [842x1186x63.35]   [LEO](2)
10/11/07 Atlas 5-421  AV011 WGS-SV1              5770  CC41  477x66847x20.1     GTO+
12/10/07 Atlas 5-401  AV015 NROL-24 (SDS?)             CC41  261x16776x60       EEO/M
03/13/08 Atlas 5-411  AV006 NRO L-28                   VA3E  1200x39000x63      EEO/M
04/14/08 Atlas 5-421  AV014 ICO G1               6630  CC41  187x35925x22.7     GTO
04/04/09 Atlas 5-421  AV016 WGS F2               5987  CC41  408x66811x20.93    GTO+
06/18/09 Atlas 5-401  AV020 LRO/LCROSS           2810  CC41  194x353700x28      HTO
09/08/09 Atlas 5-401  AV018 PAN                  3000? CC41                     GTO+?
10/18/09 Atlas 5-401  AV017 DMSP-18              1200  VA3E  857kmx99deg        LEO/S
11/23/09 Atlas 5-431  AV024 Intelsat 14          5614  CC41  6037x36823x22.48   GTO+
02/11/10 Atlas 5-401  AV021 SDO                  3100  CC41  2498x35318x28.52   GTO
04/22/10 Atlas 5-501  AV012 X-37B OTV-1          4989  CC41  400x400x40         LEO
08/14/10 Atlas 5-531  AV019 AEHF-1               6170  CC41  222x50245x22.2     GTO+
09/21/10 Atlas 5-501  AV025 NROL-41                    VA3E  1100x1100x123      LEO/R 
03/05/11 Atlas 5-501  AV026 X-37 OTV-2          ~5300  CC41                     LEO
04/15/11 Atlas 5-401  AV027 NROL-34             ~6000? VA3E  1,000x1,000x63.4   LEO
05/07/11 Atlas 5-401  AV022 SBIRS-GEO 1          4833  CC41  185x35786x21.64    GTO
08/05/11 Atlas 5-551  AV029 Juno                 3625  CC41                     HCO
11/26/11 Atlas 5-541  AV028 MSL                  3839  CC41                     HCO
02/24/12 Atlas 5-551  AV030 MUOS 1               6740  CC41  3461x35786x19      GTO
05/04/12 Atlas 5-531  AV031 AEHF-2               6170  CC41  222x50244x20.7     GTO+
06/20/12 Atlas 5-401  AV023 NROL-38                    CC41                     GTO?
08/32/12 Atlas 5-401  AV032 RBSP A/B             1316  CC41  601x30709x10       EEO
09/13/12 Atlas 5-401  AV033 NROL-36             ~6000  VA3E  1000x1000x63.4?    LEO?
12/11/12 Atlas 5-501  AV034 OTV-3(X37B-1F2)     ~5000  CC41  343x360x43.5       LEO 
01/31/13 Atlas 5-401  AV036 TDRS-K               3454  CC41  4313x35789x25.9    GTO+
02/11/13 Atlas 5-401  AV035 LDCM                 2770  VA3E  661x676x98.2       LEO/S
03/19/13 Atlas 5-401  AV037 SBIRS GEO2          ~4500  CC41  185x35786x22.19    GTO 
05/15/13 Atlas 5-401  AV039 GPS 2F-4             1540  CC41  20200x55           MEO
07/19/13 Atlas 5-551  AV040 MUOS 2               6740  CC41  3802x35787x19.1    GTO
09/18/13 Atlas 5-531  AV041 AEHF 3               6169  CC41  225x50000x20.9     GTO
11/18/13 Atlas 5-401  AV038 MAVEN                2540  CC41                     HCO
12/06/13 Atlas 5-501  AV042 NROL 39                    VA3E  1100x1100x123      LEO/R
01/24/14 Atlas 5-401  AV043 TDRS-L               3454  CC41  4839x35788x25.5    GTO+
04/03/14 Atlas 5-401  AV044 DMSP F19             1200  VA3E  853x853x98.87      LEO/S
04/10/14 Atlas 5-541  AV045 NROL-67                    CC41                     GEO?
05/22/14 Atlas 5-401  AV046 NROL-33                    CC41                     GTO?
08/02/14 Atlas 5-401  AV048 GPS 2F7              1630  CC41  20200x55           MEO
08/13/14 Atlas 5-401  AV047 Worldview 3          2812  VA3E  607x629x97.97      LEO/S
09/17/14 Atlas 5-401  AV049 CLIO                       CC41                     GTO+
10/29/14 Atlas 5-401  AV050 GPS 2F-8             1630  CC41  20200x55           MEO
12/13/14 Atlas 5-541  AV051 NROL 35                    VA3E  2101x37748x62.85   EEO/M(3)
01/21/15 Atlas 5-551  AV052 MUOS 3               6740  CC41  3817x35787x19.11   GTO

EELV Launch Forecast (Notice: Subject to Frequent and Substantial Modification)

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(2)Centaur shut down about four seconds early during its second burn, 
leaving the twin NOSS payloads in an unannounced low transfer orbit. 
Two weeks after the launch, U.S. Air Force officials reported that 
liquid hydrogen had leaked through a valve that failed to close 
properly during the coast phase, leading to a propellant shortage 
during the second burn. Amateur observers tracked the payloads, 
in 842 x 1186 km x 63.35 deg orbits, lower than the expected 
1,000 x 1,200 km x 63.4 deg. The satellites reportedly would be 
able to move themselves to operational orbits despite the shortfall. 

(3) First RL10C-1 engine flight.

*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:


References

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

 Last Update: January 21, 2015