Rocketdyne AR2

The Rocketdyne AR2, also known by the military designation LR42, was a family of liquid-fuelled rocket engines designed and produced in the United States (US) during the 1950s and 1960s.

AR2
AR2 installation of the Lockheed NF-104A
Type	liquid-fuelled rocket engine
National origin	United States
Manufacturer	Rocketdyne
First run	1950s
Major applications	Lockheed NF-104A North American F-86F(R)

Design and development

The Rocketdyne division of North American Aviation developed a relatively small liquid-fuelled rocket engine for thrust augmentation of manned aircraft during the late 1950s. The AR2 is a single-chamber rocket engine burning kerosene (JP-4 or JP-5) jet fuel, oxidised with 90% High Test Peroxide (H₂O₂ / HTP), allowing the engine to use the same fuel as an aircraft fuel system.^[1] The variable-thrust AR2 is a direct development of the fixed thrust AR1, which was given the military designation LR36.

The AR2-3 had variable-thrust and single lever throttle control, regulating flow of oxidiser to the turbo-pump gas-generator and thus flow of propellants to the combustion chamber.^[1]

Operational history

Initial flight trials were carried out attached to the belly of North American F-86F-30-NA Sabre (52-4608 / FU-608) re-designated F-86F(R), boosting performance to a top speed of M1.22 at 60,000 ft (18,288 m).^[2]

The AR2-3 was evaluated in 1999 as part of the Future-X Demonstrator Engine project, for possible use in the Boeing X-37 Reusable Upper Stage Vehicle at a thrust of 6,600 lbf (29.34 kN), with a specific impulse of 245 seconds.^[3][4]

Variants

AR-1

(YLR36-NA-2) Initial fixed-thrust variant.^[5]

AR2-1

(YLR42-NA-2) prototype, test and development variable-thrust engines.^[6][5]

AR2-2

test and development engines.^[6]

AR2-3

Production engines for research and development projects like the NF-104A.^[7]

Applications

• North American F-86F(R)
• Lockheed NF-104A

Specifications (AR2-3)

Data from Astronautix : AR2-3 ^[3] and Aircraft engines of the World 1964/65.^[1]

General characteristics

• Type: liquid-fuelled rocket engine
• Length:
• Diameter:
• Dry weight:
• Fuel: Kerosene (JP-4 / JP-5)
• Oxidiser: High-test peroxide (H₂O₂)

Components

• Pumps: turbopumps driven by High-test peroxide (H₂O₂) decomposed by a catalyst

Performance

• Thrust: 3,000 lbf (13.34 kN) to 6,000 lbf (26.69 kN)
  • Combustion chamber temperature: 4,600 °F (2,811 K; 2,538 °C)
  • Combustion chamber pressure: 560 psi (3,861 kPa)
  • Specific impulse: 245 seconds
• Burn time: