J-2

E130634

liquid-fueled rocket engine rocket engine

The J-2 was a liquid-fueled rocket engine used on NASA’s Saturn rockets to power upper stages during the Apollo and early Skylab missions.

Try in SPARQL Jump to: Surface forms Disambiguation Statements Elicitation Referenced by

All labels observed (4)

Label	Occurrences
J-2 canonical	4
J-2X	2
J-2 rocket engine	1
J-2S	1

How this entity was disambiguated

This entity first appeared as the object of triple T1116664 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.

NED1 Entity disambiguation (via context triple) gpt-5-mini-2025-08-07

Target entity: J-2
Context triple: [Saturn V, secondStageEngineType, J-2]

A. RL10
RL10 is a family of high-performance, liquid hydrogen–liquid oxygen cryogenic rocket engines developed by Aerojet Rocketdyne and widely used on U.S. upper stages such as Centaur and Delta IV.
B. LC-39B
LC-39B is a launch pad at NASA’s Kennedy Space Center that has supported major crewed and uncrewed space missions, including Space Shuttle flights and later Space Launch System operations.
C. Vulcan Centaur
Vulcan Centaur is United Launch Alliance’s next-generation, two-stage heavy-lift rocket designed to replace Atlas V and Delta IV for a wide range of commercial, government, and deep-space missions.
D. Saturn V
Saturn V was a powerful American heavy-lift launch vehicle used during the Apollo and Skylab programs to send astronauts and payloads into space, including missions to the Moon.
E. Interim Cryogenic Propulsion Stage
The Interim Cryogenic Propulsion Stage is a liquid hydrogen–liquid oxygen upper stage used on early NASA Space Launch System missions to provide orbital insertion and translunar injection capability before the introduction of a more powerful exploration upper stage.
F. None of above. chosen
G. Unsure - the case is ambiguous/there is not enough information to decide.

NED2 Entity disambiguation (via description) gpt-5-mini-2025-08-07

Target entity: J-2
Target entity description: The J-2 was a liquid-fueled rocket engine used on NASA’s Saturn rockets to power upper stages during the Apollo and early Skylab missions.

A. RL10
RL10 is a family of high-performance, liquid hydrogen–liquid oxygen cryogenic rocket engines developed by Aerojet Rocketdyne and widely used on U.S. upper stages such as Centaur and Delta IV.
B. LC-39B
LC-39B is a launch pad at NASA’s Kennedy Space Center that has supported major crewed and uncrewed space missions, including Space Shuttle flights and later Space Launch System operations.
C. Vulcan Centaur
Vulcan Centaur is United Launch Alliance’s next-generation, two-stage heavy-lift rocket designed to replace Atlas V and Delta IV for a wide range of commercial, government, and deep-space missions.
D. Saturn V
Saturn V was a powerful American heavy-lift launch vehicle used during the Apollo and Skylab programs to send astronauts and payloads into space, including missions to the Moon.
E. Interim Cryogenic Propulsion Stage
The Interim Cryogenic Propulsion Stage is a liquid hydrogen–liquid oxygen upper stage used on early NASA Space Launch System missions to provide orbital insertion and translunar injection capability before the introduction of a more powerful exploration upper stage.
F. None of above. chosen

Statements (45)

Predicate	Object
instanceOf	liquid-fueled rocket engine ⓘ rocket engine ⓘ
bellNozzle	yes ⓘ
chamberPressure	approximately 5.0 MPa ⓘ
countryOfOrigin	United States of America ⓘ surface form: United States
cycleType	gas-generator cycle ⓘ
developedFor	Saturn rocket family ⓘ surface form: Saturn launch vehicle family
firstFlight	1966 ⓘ
fuel	liquid hydrogen ⓘ
gimbalCapability	gimbaled for thrust vector control ⓘ
historicalSignificance	enabled translunar injection for Apollo missions ⓘ one of the first large LH2/LOX engines in operational service ⓘ
manufacturer	Aerojet Rocketdyne ⓘ surface form: Rocketdyne
numberOfEnginesOnSII	5 ⓘ
numberOfEnginesOnSIVB	1 ⓘ
operatedIn	near-vacuum conditions ⓘ
oxidizer	liquid oxygen ⓘ
propellantType	liquid hydrogen ⓘ liquid oxygen ⓘ
restartCapability	restartable in flight ⓘ
specificImpulseVacuum	approximately 421 s ⓘ
status	retired ⓘ
successor	J-2 self-linksurface differs ⓘ surface form: J-2S J-2 self-linksurface differs ⓘ surface form: J-2X
thrustVacuum	approximately 1,033 kN ⓘ approximately 232,000 lbf ⓘ
usedBy	NASA ⓘ
usedDuringMission	Apollo 11 ⓘ Apollo 17 ⓘ Apollo 6 ⓘ Apollo 8 ⓘ Skylab 1 ⓘ
usedFor	Apollo program ⓘ Saturn V S-II second stage ⓘ surface form: Saturn upper stages Skylab program ⓘ
usedForFunction	second stage propulsion ⓘ third stage propulsion ⓘ
usedInConfiguration	cluster of five engines on Saturn V S-II ⓘ single engine on S-IVB stage ⓘ
usedOn	Saturn I ⓘ Saturn IB ⓘ Saturn V ⓘ
usedOnStage	S-IVB ⓘ surface form: Saturn IB S-IVB stage Saturn V S-II second stage ⓘ surface form: Saturn V S-II stage S-IVB ⓘ surface form: Saturn V S-IVB stage

How these facts were elicited

Referenced by (8)

Full triples — surface form annotated when it differs from this entity's canonical label.

Saturn V → secondStageEngineType → J-2 ⓘ

Saturn V → thirdStageEngineType → J-2 ⓘ

S-IVB → rocketEngine → J-2 ⓘ

J-2 → successor → J-2 self-linksurface differs ⓘ

this entity surface form: J-2S

J-2 → successor → J-2 self-linksurface differs ⓘ

this entity surface form: J-2X

Saturn V S-II second stage → engineType → J-2 ⓘ

this entity surface form: J-2 rocket engine

Saturn IB → secondStageEngineType → J-2 ⓘ

Ares V (cancelled) → upperStageEngineType → J-2 ⓘ

subject surface form: Ares V