Research any topic before you write.

Find related topics. | Discover entities. | See connections. | Build a topical map.

LR91

The LR91 was an American liquid-propellant rocket engine, which was used on the second stages of Titan intercontinental ballistic missiles and launch vehicles. While the original version - the LR91-3 - ran on RP-1/LOX (as did the companion LR87-3) on the Titan I, the models that propelled the Titan II and later were switched to Aerozine 50/N2O4.

Products, Overview & Versions

Use the mouse wheel or two fingers (on touchscreens) to zoom in and out of the map.

Research this topic

Explore the main themes, entities and connections around LR91. Start with the topic map, then use the sections below for research and deeper semantic analysis.

Explore this topic

Start with a few of the strongest sections from the source topic. These are research directions, not a list of keywords you must use.

Key facts & relationships

High-confidence facts extracted from structured source data. Use them as anchors for further research.

Application
Upper stage
Associated LV
Titan
Burn time
247 seconds
Chamber
1
Chamber pressure
5.93 MPa (860 psi)
Country of origin
United States

Topics to explore

Browse the full topic structure. Each item opens a new analysis centered on that subject.

Overview

Versions

Advanced semantic analysis

Deeper signals for content research, entity SEO and topical coverage. The plain-language headings explain what each technical view is useful for.

Map overview Semantic statistics

LR91

Nodes23
Edges22
Triples45
Avg. degree1.91
Density0.086957
Components1

How this topic connects Entity context

See the strongest relationship patterns around the current topic before diving into the raw triples.

LR91

Top relations

related to Versions · 21
LR91 → Aerozine, Gemini Titan II, LR91-11, LR91-3, LR91-5, LR91-5LR91-7LR91-11, LR91-7, LR91-9, N2O4, Propellant, RP-1/LOX, Run, Similar, Stage, This, Titan, Titan II, Titan III, Titan IV, Used
Application · 1
LR91 → Upper stage
Associated LV · 1
LR91 → Titan
Burn time · 1
LR91 → 247 seconds
Chamber · 1
LR91 → 1
Chamber pressure · 1
LR91 → 5.93 MPa (860 psi)
Country of origin · 1
LR91 → United States
Cycle · 1
LR91 → Gas-generator
Designer · 1
LR91 → Aerojet
Diameter · 1
LR91 → 1.63 m (5 ft 4 in)

Important terminology Word statistics

Use these terms to understand the vocabulary surrounding the topic, not as a checklist for keyword stuffing.

Important terminology

titan used ii version engine rp-1 stage n2o4 aerozine 50 gas-generator missiles launch ran liquid oxygen lr87 lr91-11 iii vacuum

Entity relationships Subject–Predicate–Object triples

SubjectPredicateObjectConfidenceSrc
LR91ApplicationUpper stage1.00infobox
LR91Associated LVTitan1.00infobox
LR91Burn time247 seconds1.00infobox
LR91Chamber11.00infobox
LR91Chamber pressure5.93 MPa (860 psi)1.00infobox
LR91Country of originUnited States1.00infobox
LR91CycleGas-generator1.00infobox
LR91DesignerAerojet1.00infobox
LR91Diameter1.63 m (5 ft 4 in)1.00infobox
LR91Dry mass589 kg (1,299 lb)1.00infobox
LR91First flight1 September 1964 (1964-09-01)1.00infobox
LR91Last flight19 October 2005 (2005-10-19)1.00infobox
LR91Length2.81 m (9 ft 3 in)1.00infobox
LR91ManufacturerAerojet1.00infobox
LR91Mixture ratio1.861.00infobox
LR91Nozzle ratio49.21.00infobox
LR91PredecessorLR91-91.00infobox
LR91Propellant.mw-parser-output .template-chem2-su{display:inline-block;font-size:80%;line-height:1;vertical-align:-0.35em}.mw-parser-output .template-chem2-su>span{display:block;text-align:l…1.00infobox
LR91Specific impulse, sea-level160 s (1.6 km/s)1.00infobox
LR91Specific impulse, vacuum316 s (3.10 km/s)1.00infobox
LR91StatusRetired1.00infobox
LR91Thrust, sea-level232.7 kN (52,300 lbf)1.00infobox
LR91Thrust, vacuum467 kN (105,000 lbf)1.00infobox
LR91Thrust-to-weight ratio80.851.00infobox

Related concept clusters Concept neighborhoods

These clusters group vocabulary that occurs around closely connected concepts in the source material.

    Connections between topic areas Semantic bridges

    Bridges can reveal useful research angles that are easy to miss in a flat list of related terms.

    Min side: 3
    For writers, content strategists, SEOs, marketers and creators — from quick topic research to advanced semantic analysis.