Able (rocket stage)

The Able rocket stage was a rocket stage manufactured in the United States by Aerojet as the second of three stages of the Vanguard rocket used in the Vanguard project from 1957 to 1959. The Able stage name represents its place as the first in the series, from the Joint Army/Navy Phonetic Alphabet.^[1]

To save weight Aerojet used an aluminum tube for the engine thrust chamber. The engine used on Vanguard was an AJ10-37, burning nitric acid and UDMH as rocket propellants.On later Able models rockets the AJ10-41 and AJ10-42 engines were used. Aerojet made 21 Able rocket stages for use on launchers.^[2] The Vanguard project launched 11 Able stages. Three put satellites into orbit: Vanguard 1, Vanguard 2 and Vanguard 3. The Able rocket stage and the Vanguard project were an important part of the Space Race between the US and Soviet Union.^{[citation needed]} The AJ10 engines used in the Able rocket stage continue to be used on later rockets and are still in use. In honor of the rocket stage during an animals in space test, a rhesus monkey named Miss Able, flew with Miss Baker on May 28, 1959.^[3] Later Able stages used AJ10-101 or AJ10-101A rocket engines.

The Able rocket stage was discontinued in 1960. A version of the AJ10 engine used for the Able rocket stage was used as the engine of Apollo Service Module.^[4]

The improved Able-Star version was used as the upper stage of the Thor-Ablestar two stage launcher. The Able-Star second stage was an enlarged version of the Able rocket stage using AJ10-104 or AJ10-104D engines, which gave the Thor-Ablestar a greater payload capacity compared to the earlier Thor-Able.^[5] It also incorporated restart capabilities, allowing a multiple-burn trajectory to be flown, further increasing payload, or allowing the rocket to reach different orbits. It was the first rocket to be developed with such a capability and development of the stage took a mere eight months.^[6]

Specifications

Able

Loaded gross mass: 1,884 kg (4,154 lb)^[2]
Empty (unfueled) mass 429 kg (946 lb)^[2]
Thrust 34.69 kN (7,800 lb_f)^[2]
Specific impulse (vacuum) 270 seconds (2.6 km/s)^[2]
Height: 5.67 m (18.6 ft)^[2]
Diameter: 0.81 m (2 ft 8 in)^[2]
Span: 0.84 m (2 ft 9 in)^[2]
Burn time: 115 seconds^[2]
Engine: AJ10-40, AJ10-101^[2]

References

^ Helen T. Wells; Susan H. Whiteley; Carrie E. Karegeannes. Origin of NASA Names. NASA Science and Technical Information Office. p. 5.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Wade. "Able". Encyclopedia Astronautica. Archived from the original on 2016-08-27. Retrieved 2025-06-14.
^ Darling, David. "Able". www.daviddarling.info. Retrieved 2025-06-14.
^ The First Space Race: Launching the World's First Satellites, By Matt Bille, Erika Lishock, page 163 and page 174
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ "Able-Star". www.astronautix.com. Retrieved 2025-07-27.
^ Wade, Mark. "Delta". Encyclopedia Astronautica. Archived from the original on 24 July 2008. Retrieved 30 November 2008.

[1] Helen T. Wells; Susan H. Whiteley; Carrie E. Karegeannes. Origin of NASA Names. NASA Science and Technical Information Office. p. 5.

[:1-2] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Wade. "Able". Encyclopedia Astronautica. Archived from the original on 2016-08-27. Retrieved 2025-06-14.

[3] Darling, David. "Able". www.daviddarling.info. Retrieved 2025-06-14.

[4] The First Space Race: Launching the World's First Satellites, By Matt Bille, Erika Lishock, page 163 and page 174

[:0-5] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ "Able-Star". www.astronautix.com. Retrieved 2025-07-27.

[EA-6] Wade, Mark. "Delta". Encyclopedia Astronautica. Archived from the original on 24 July 2008. Retrieved 30 November 2008.

[1]

[2]

[3]

[4]

[5]

[6]

v t e Upper stages
Active	AVUM Briz Castor 30 Centaur CTS / SMA DCSS DM-03 Fregat Star 27 / 37 / 48 Starship Volga Yuanzheng
Planned	Advanced Cryogenic Evolved Stage Exploration Upper Stage KVTK
Retired	Agena Able Altair Astris Blok 2BL Blok D Burner Delta-D Delta-K Delta-P EPKM FG-02 Ikar Inertial Upper Stage KVD-1 Payload Assist Module Saturn IV Saturn IVB Transfer Orbit Stage Transtage

v t e Project Vanguard
Launches	TV-0 TV-1 TV-2 TV-3 TV-3BU TV-4 TV-5 SLV-1 SLV-2 SLV-3 SLV-4 SLV-5 SLV-6 SLV-7/TV4-BU
Satellites	Vanguard 1 Vanguard 2 Vanguard 3

v t e Orbital launch systems
List of orbital launch systems Comparison of orbital launch systems
Current	Angara 1.2 A5 Ariane 6 Atlas V Ceres 1 1S Chollima-1 Electron Eris^† Falcon 9 Block 5 Falcon Heavy Firefly Alpha Gravity-1 GSLV H3 Hyperbola-1 Jielong 1 3 KAIROS^† Kaituozhe 2 Kinetica 1 Kuaizhou 1 1A 11 Long March 2C 2D 2F 3A 3B/E 3C 4B 4C 5 5B 6 6A 6C 7 7A 8 11 11H 12 LVM3 Minotaur I IV V C New Glenn Nuri OS-M1^† Pegasus XL Proton-M PSLV Qaem 100 Qased Shavit 2 Simorgh SLS Block 1 Soyuz-2 2.1a / STA 2.1b / STB Spectrum^† SSLV Starship Tianlong-2 Unha Vega C Vulcan Centaur Zhuque 2
In development	Antares 330 Bloostar Blue Whale 1 Cyclone-4M Deca Eclipse Epsilon S Gravity-2 HANBIT-NANO Hyperbola-2 Irtysh KSLV-III Kuaizhou 21 31 Long March 9 10 Miura 5 Neutron New Line 1 NGLV Nova OS-M 2 4 Orbex Prime Pallas-1 Red Dwarf RFA One SLS Block 1B Block 2 Soyuz-7 Terran R Tianlong-3 VLM Vega E Zero Zhuque 3 Zuljanah
Retired	Antares 110 120 130^† 230 230+ Ariane 1 2 3 4 5 ASLV Athena I II Atlas B D E/F G H I II III LV-3B SLV-3 Able^† Agena Centaur Black Arrow Conestoga^† Delta A B C D E G J L M N 0100 1000 2000 3000 4000 5000 II III IV IV Heavy Diamant Dnepr Energia Epsilon Europa I^† II^† Falcon 1 Falcon 9 v1.0 v1.1 v1.2 "Full Thrust" Feng Bao 1 GSLV Mk I H-I H-II H-IIA H-IIB Juno I Juno II Kaituozhe-1 Kosmos original 1 2/2I 3 3M Lambda 4S LauncherOne Long March 1 1D^† 2A 2E 3 3B 4A Mu 4S 3C 3H 3S 3SII V N1^† N-I N-II Naro-1 Paektusan^† Pilot-2^† R-7 Luna Molniya M L Polyot Soyuz original FG L M U U2 2-1v Soyuz/Vostok Sputnik Voskhod Vostok L K 2 2M R-29 Shtil' Volna^† Rocket 3 RS1^† Safir 1 1A 1B Saturn I IB V Scout X-1 Blue Scout II^† X-2^† X-2M X-3 X-3M X-4 X-2B^† B A B-1 D-1 A-1 E-1 F-1 G-1 Shavit original 1 SLV Space Shuttle SPARK^† Sparta SS-520 Start-1 Terran 1^† Thor Able Ablestar 1 2 Agena A B D Burner 1 2 Delta DSV-2U Thorad-Agena SLV-2G SLV-2H Titan II GLV IIIA IIIB IIIC IIID IIIE 34D 23G CT-3 IV Tsyklon R-36-O original 2 3 Universal Rocket UR-500 Proton Proton-K Rokot Strela Vanguard Vega original VLS-1^† Zenit 2 2M 2FG 3SL 3SLB 3F Zhuque 1^†
Classes	Sounding rocket Small-lift launch vehicle Medium-lift launch vehicle Heavy-lift launch vehicle Super heavy-lift launch vehicle
This template lists historical, current, and future space rockets that at least once attempted (but not necessarily succeeded in) an orbital launch or that are planned to attempt such a launch in the future Symbol ^† indicates past or current rockets that attempted orbital launches but never succeeded (never did or has yet to perform a successful orbital launch)

v t e Orbital launch systems developed in the United States
Active	Atlas V**^†† Electron Falcon 9 Block 5 Falcon Heavy Firefly Alpha Minotaur I IV V C New Glenn Pegasus XL SLS Block 1 Vulcan Centaur
In development	Antares 330 Daytona I Eclipse Neutron Nova Red Dwarf SLS Block 1B Block 2 Starship Terran R
Retired	Antares 110/120/130/230/230+^††† Athena I II Atlas B D E/F G H I II III LV-3B SLV-3 Able Agena Centaur Conestoga Delta A B C D E G J L M N 0100 1000 2000 3000 4000 5000 II III IV IV Heavy Falcon 1 Falcon 9 v1.0 v1.1 v1.2 "Full Thrust" H-I* Juno I Juno II LauncherOne N-I* N-II* Pilot Rocket 3 RS1^† Saturn I IB V Scout Space Shuttle SPARK Sparta Terran 1^† Thor Able Ablestar Agena Burner Delta DSV-2U Thorad-Agena Titan II GLV IIIA IIIB IIIC IIID IIIE 34D 23G CT-3 IV Vanguard
* - Japanese projects using US rockets or stages ** - uses Russian engines ^† - never succeeded ^†† - no new orders accepted and production stopped ^††† - used Ukrainian first stage

Specifications

Able

Able-Star

See also

References