Reaction Motors XLR99
E106917
The Reaction Motors XLR99 was a pioneering throttleable, restartable liquid-fuel rocket engine that powered the North American X-15 research aircraft to record-breaking speeds and altitudes during the early space age.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Reaction Motors XLR99 canonical | 4 |
How this entity was disambiguated
This entity first appeared as the object of triple T900496 — 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: Reaction Motors XLR99 Context triple: [North American X-15, engineModel, Reaction Motors XLR99]
-
A.
Reaction Motors XLR11
The Reaction Motors XLR11 was an early liquid-fueled rocket engine used in pioneering U.S. experimental aircraft, notably enabling the Bell X-1 to break the sound barrier.
-
B.
Curtiss-Wright XLR25 rocket engine
The Curtiss-Wright XLR25 was an American liquid-fueled rocket engine developed in the 1950s to power high-speed experimental research aircraft such as the Bell X-2.
-
C.
Rocket V8 engine
The Rocket V8 engine was Oldsmobile’s pioneering overhead-valve V8 introduced in the late 1940s, widely credited with helping launch the American high-performance and muscle car era.
-
D.
Mitsubishi Kinsei radial engine
The Mitsubishi Kinsei was a Japanese air-cooled radial aircraft engine widely used in World War II combat aircraft.
-
E.
Ramport Aero
Ramport Aero is the company responsible for managing and operating Zhukovsky International Airport near Moscow, Russia.
- 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: Reaction Motors XLR99 Target entity description: The Reaction Motors XLR99 was a pioneering throttleable, restartable liquid-fuel rocket engine that powered the North American X-15 research aircraft to record-breaking speeds and altitudes during the early space age.
-
A.
Reaction Motors XLR11
The Reaction Motors XLR11 was an early liquid-fueled rocket engine used in pioneering U.S. experimental aircraft, notably enabling the Bell X-1 to break the sound barrier.
-
B.
Curtiss-Wright XLR25 rocket engine
The Curtiss-Wright XLR25 was an American liquid-fueled rocket engine developed in the 1950s to power high-speed experimental research aircraft such as the Bell X-2.
-
C.
Rocket V8 engine
The Rocket V8 engine was Oldsmobile’s pioneering overhead-valve V8 introduced in the late 1940s, widely credited with helping launch the American high-performance and muscle car era.
-
D.
Mitsubishi Kinsei radial engine
The Mitsubishi Kinsei was a Japanese air-cooled radial aircraft engine widely used in World War II combat aircraft.
-
E.
Ramport Aero
Ramport Aero is the company responsible for managing and operating Zhukovsky International Airport near Moscow, Russia.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
liquid-fuel rocket engine
ⓘ
rocket engine ⓘ |
| chamberPressure |
approximately 3.4 MPa
ⓘ
approximately 500 psi ⓘ |
| control | throttle controlled from X-15 cockpit ⓘ |
| coolingMethod | regenerative cooling ⓘ |
| countryOfOrigin |
United States
ⓘ
linked to:
United States of America
|
| cycleType | gas-generator cycle ⓘ |
| designation | XLR99-RM-1 ⓘ |
| developmentPeriod | 1950s ⓘ |
| era | early space age ⓘ |
| firstFlightUse |
X-15 flight program
ⓘ
linked to:
North American X-15
|
| fuel | anhydrous ammonia ⓘ |
| gimbalCapability | gimballed for thrust vector control ⓘ |
| heritage | influenced later man-rated rocket engine designs ⓘ |
| ignitionSystem | hypergolic igniter fluid ⓘ |
| manufacturer | Reaction Motors Inc. ⓘ |
| notableFeature |
designed for high reliability in crewed flight
ⓘ
first large throttleable man-rated liquid rocket engine ⓘ restartable in flight ⓘ |
| numberOfCombustionChambers | 1 ⓘ |
| operatedBy | X-15 test pilots ⓘ |
| oxidizer | liquid oxygen ⓘ |
| poweredRecord |
X-15 altitude record above 50 miles
ⓘ
X-15 speed record over Mach 6 ⓘ suborbital spaceflight altitudes for X-15 ⓘ |
| program |
X-15 program
ⓘ
linked to:
North American X-15
|
| propellantFeed | turbopump-fed ⓘ |
| propellantType | liquid propellant ⓘ |
| restartable | true ⓘ |
| specificImpulseSeaLevel | about 250 s ⓘ |
| specificImpulseVacuum | about 279 s ⓘ |
| status | retired ⓘ |
| throttleable | true ⓘ |
| thrustRange |
approximately 125 to 254 kN
ⓘ
approximately 28,000 to 57,000 lbf ⓘ |
| thrustVacuum |
about 254 kN
ⓘ
about 57,000 lbf ⓘ |
| usedBy |
NASA
ⓘ
United States Air Force ⓘ |
| usedFor |
X-15 high-altitude research
ⓘ
X-15 high-speed research ⓘ aeronautical research ⓘ early spaceflight research ⓘ |
| usedIn |
hypersonic flight research
ⓘ
pilot physiology research at extreme altitudes ⓘ reentry heating studies ⓘ |
| usedOn | North American X-15 ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Reaction Motors XLR99 Description of subject: The Reaction Motors XLR99 was a pioneering throttleable, restartable liquid-fuel rocket engine that powered the North American X-15 research aircraft to record-breaking speeds and altitudes during the early space age.
Referenced by (4)
Full triples — surface form annotated when it differs from this entity's canonical label.