RL10
An RL10 at the U.S. Space & Rocket Center with cutaway showing tubing through the bell.
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Country of origin | United States of America |
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First flight | 1962 (RL10A-1) |
Designer | Pratt & Whitney/MSFC |
Manufacturer | Pratt & Whitney Space Propulsion Pratt & Whitney Rocketdyne Aerojet Rocketdyne |
Application | Upper stage engine |
Associated L/V | Atlas Titan Delta IV Saturn I |
Status | In production |
Liquid-fuel engine | |
Propellant | Liquid oxygen / Liquid hydrogen |
Mixture ratio | 5.5 or 5.85:1 |
Cycle | Expander cycle |
Configuration | |
Nozzle ratio | 84:1 or 280:1 |
Performance | |
Thrust (vac.) | 110 kN (25,000 lbf) |
Isp (vac.) | 450 to 465.5 seconds (4.413 to 4.565 km/s) |
Burn time | 700 seconds |
Dimensions | |
Length | 4.14 m (13.6 ft) (nozzle extended) |
Diameter | 2.13 m (7 ft 0 in) |
Dry weight | 277 kg (611 lb) |
Used in | |
Centaur S-IV DCSS |
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References | |
References | [1] |
Notes | Performance values and dimensions are for RL-10B-2. |
The RL10 is a liquid-fuel cryogenic rocket engine used on the Centaur, S-IV and DCSS upper stages. Built in the United States by Aerojet Rocketdyne (formerly by Pratt & Whitney Rocketdyne), the RL10 burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). of thrust in vacuum depending on the version in use. The RL10 was the first liquid hydrogen rocket engine to be built in the United States, and development of the engine by Marshall Space Flight Center and Pratt & Whitney began in the 1950s, with the first flight occurring in 1961. Several versions of the engine have been flown, with two, the RL10A-4-2 and the RL10B-2, still being produced and flown on the Atlas V and Delta IV.
The engine produces a specific impulse (Isp) of 373 to 470 s (3.66–4.61 km/s) in a vacuum and has a mass ranging from 131 to 317 kg (289–699 lb) (depending on version). Six RL10A-3 engines were used in the S-IV second stage of the Saturn I rocket, one or two RL10 engines are used in the Centaur upper stages of Atlas and Titan rockets and one RL10B-2 is used in the upper stage of Delta IV rockets.
Contents
History
The RL10 was first tested on the ground in 1959, at Pratt and Whitney's Florida Research and Development Center in West Palm Beach, Florida.[2] It was first flown in 1962 in an unsuccessful suborbital test;[3] the first successful flight took place on November 27, 1963.[4][5] For that launch, two RL10A-3 engines powered the Centaur upper stage of an Atlas launch vehicle. The launch was used to conduct a heavily instrumented performance and structural integrity test of the vehicle.[6] The RL-10 was designed for the USAF from the beginning as a throttleable motor for the Lunex lunar lander, finally putting this capability to use twenty years later in the DC-X VTOL vehicle.[7]
Improvements
The RL10 has been upgraded over the years. One current model, the RL10B-2, powers the Delta IV second stage, as well as the Delta III second stage. It has been significantly modified from the original RL10 to improve performance. Some of the enhancements include an extendable nozzle and electro-mechanical gimbaling for reduced weight and increased reliability. Current specific impulse is 464 seconds (4.55 km/s).
A flaw in the brazing of an RL10B-2 combustion chamber was identified as the cause of failure for the May 4, 1999, Delta III launch carrying the Orion-3 communications satellite.[8]
Applications for the RL10
Four modified RL10A-5 engines, all of them with the ability to be throttled, were used in the McDonnell Douglas DC-X.[citation needed]
The DIRECT version 3.0 proposal to replace Ares I and Ares V with a family of rockets sharing a common core stage, recommends the RL10 for the second stage of their proposed J-246 and J-247 launch vehicles.[9] Up to seven (7) RL10 engines would be used in the proposed Jupiter Upper Stage, serving an equivalent role to the Ares V Earth Departure Stage.
Potential uses for the RL10
Common Extensible Cryogenic Engine
The Common Extensible Cryogenic Engine (CECE) is a testbed to develop RL10 engines that throttle well. NASA has contracted with Pratt & Whitney Rocketdyne to develop the CECE demonstrator engine.[10] In 2007 its operability (with some "chugging") was demonstrated at 11-to-1 throttle ratios.[11] In 2009 NASA reported successfully throttling from 104 percent thrust to eight percent thrust, a record for an engine of this type. Chugging was eliminated by injector and propellant feed system modifications that control the pressure, temperature and flow of propellants.[12]
Advanced Common Evolved Stage
As of 2009[update], an enhanced version of the RL10 rocket engine was proposed to power the upper-stage versions of the Advanced Common Evolved Stage (ACES), a long-duration, low-boiloff extension of existing ULA Centaur and Delta Cryogenic Second Stage (DCSS) technology.[13] Long-duration ACES technology is explicitly designed to support geosynchronous, cislunar, and interplanetary missions as well as provide in-space propellant depots in LEO or at L2 that could be used as way-stations for other rockets to stop and refuel on the way to beyond-LEO or interplanetary missions. Additional missions could include the provision of the high-energy technical capacity for the cleanup of space debris.[14]
NextGen Propulsion Study
NASA is partnering with the US Air Force (USAF) to study next-generation upper stage propulsion, formalizing the agencies joint interests in a new upper stage engine to replace the venerable Aerojet Rocketdyne RL10.
"We know the list price on an RL10. If you look at cost over time, a very large portion of the unit cost of the EELVs is attributable to the propulsion systems, and the RL10 is a very old engine, and there's a lot of craftwork associated with its manufacture," says Dale Thomas, associate director of technical issues at NASA Marshall. "That's what this study will figure out, is it worthwhile to build an RL10 replacement?"
USAF hopes to replace the Rocketdyne RL10 engines used on the upper stage of both the Lockheed Martin Atlas V and the Boeing Delta IV, known as evolved expendable launch vehicles (EELV) that are the primary method of putting US satellites into space. While NASA frequently uses EELVs to launch large scientific payloads, the programme's administration is largely run through other channels.[15]
Variants
Version | Status | First flight | Dry mass | Thrust | Isp (vac) | Length | Diameter | T:W | O:F | Expansion ratio | Chamber pressure | Burn time | Associated stage | Notes |
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RL10A-1 | Retired | 1962 | 131 kg (289 lb) | 66.7 kN (15,000 lbf) | 425 s (4.17 km/s) | 1.73 m (5 ft 8 in) | 1.53 m (5 ft 0 in) | 52:1 | 40:1 | 430 s | Centaur A | Prototype [16][17][18] |
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RL10A-3 | Retired | 1963 | 131 kg (289 lb) | 65.6 kN (14,700 lbf) | 444 s (4.35 km/s) | 2.49 m (8 ft 2 in) | 1.53 m (5 ft 0 in) | 51:1 | 5:1 | 57:1 | 32.75 bar (3,275 kPa) | 470 s | Centaur B/C/D/E S-IV |
[19] |
RL10A-4 | Retired | 1992 | 168 kg (370 lb) | 92.5 kN (20,800 lbf) | 449 s (4.40 km/s) | 2.29 m (7 ft 6 in) | 1.17 m (3 ft 10 in) | 56:1 | 5.5:1 | 84:1 | 392 s | Centaur IIA | [20] | |
RL10A-4-1 | Retired | 2000 | 167 kg (368 lb) | 99.1 kN (22,300 lbf) | 451 s (4.42 km/s) | 1.53 m (5 ft 0 in) | 61:1 | 84:1 | 740 s | Centaur IIIA | [21] | |||
RL10A-4-2 | In production | 2002 | 167 kg (368 lb) | 99.1 kN (22,300 lbf) | 451 s (4.42 km/s) | 1.53 m (5 ft 0 in) | 61:1 | 84:1 | 740 s | Centaur IIIB Centaur V1 Centaur V2 |
[22] | |||
RL10A-5 | Retired | 1993 | 143 kg (315 lb) | 64.7 kN (14,500 lbf) | 373 s (3.66 km/s) | 1.07 m (3 ft 6 in) | 1.02 m (3 ft 4 in) | 46:1 | 6:1 | 4:1 | 127 s | DC-X | [23] | |
RL10B-2 | In production | 1998 | 277 kg (611 lb) | 110 kN (25,000 lbf) | 462 s (4.53 km/s) | 4.14 m (13.6 ft) | 2.13 m (7 ft 0 in) | 40:1 | 5.85:1 | 280:1 | 44.12 bar (4,412 kPa) | 700 s | Delta Cryogenic Second Stage | [1] |
RL10B-X | Cancelled | 317 kg (699 lb) | 93.4 kN (21,000 lbf) | 470 s (4.6 km/s) | 1.53 m (5 ft 0 in) | 30:1 | 250:1 | 408 s | Centaur B-X | [24] | ||||
CECE | In development | 160 kg (350 lb) | 66.7 kN (15,000 lbf) | >445 s (4.36 km/s) | 1.53 m (5 ft 0 in) | Base demonstrator [25][26] |
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RL10C-1 | In testing | 12/2014 | 191 kg (421 lb) | 106.31 kN (23,900 lbf) | 448.5 s (4.398 km/s) | 2.22 m (7 ft 3 in) | 1.44 m (4 ft 9 in) | 57:1 | 5.88:1 | 130:1 | 2000 | Centaur | [27][28] |
Specifications
Original RL10
- Thrust (altitude): 15,000 lbf (66.7 kN)[17]
- Burn Time: 470 s[17]
- Design: Expander cycle[citation needed]
- Specific impulse: 433 seconds (4.25 km/s)[citation needed]
- Engine weight - dry: 298 lb (135 kg)
- Height: 68 in (1.73 m)
- Diameter: 39 in (0.99 m)
- Nozzle expansion ratio: 40 to 1
- Propellants: Liquid Oxygen & Liquid Hydrogen
- Propellant flow: 35 lb/s (16 kg/s)
- Contractor: Pratt & Whitney
- Vehicle application: Saturn I / S-IV 2nd stage - 6-engines
- Vehicle application: Centaur upper stage - 2-engines
Current design
- RL10B-2 Specifications
- Thrust (altitude): 24,750 lbf (110.1 kN)[29]
- Design: Expander cycle[30]
- Specific impulse: 464 seconds (4.55 km/s)[29]
- Engine weight - dry: 610 lb (277 kg)[29]
- Height: 163 in (4.14 m)[29]
- Diameter: 87 in (2.21 m)[29]
- Expansion ratio: 250 to 1
- Mixture ratio: 5.85 to 1 [29]
- Propellants: Liquid oxygen & liquid hydrogen[29]
- Propellant flow: Oxidizer 41.42 lb/s (20.6 kg/s), fuel 7.72 lb/s (3.5 kg/s)[29]
- Contractor: Pratt & Whitney
- Vehicle application: Delta III, Delta IV second stage (1 engine)
- RL10A-4-2
The other current model, the RL10A-4-2, is the engine used on Centaur upper stage for Atlas V.[29]
Engines on display
- An RL10 is on display at the New England Air Museum, Windsor Locks, Connecticut[31]
- An RL10 is on display at the Museum of Science and Industry, Chicago, Illinois[32]
- An RL10 is on display at the U.S. Space & Rocket Center, Huntsville, Alabama[32]
- An RL10 is on display at Southern University, Baton Rouge, Louisiana[33]
- Two RL10 engines are on display at US Space Walk of Fame, Titusville, Florida [34]
See also
- Spacecraft propulsion
- RL60
- RD-0146
- XCOR/ULA aluminum alloy nozzle engine, under development in 2011
References
- Notes
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- ↑ Connors, p 319
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- ↑ [1]
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- ↑ [2]
- ↑ 29.0 29.1 29.2 29.3 29.4 29.5 29.6 29.7 29.8 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ https://www.facebook.com/SpaceWalkOfFame/photos/pcb.10152534325180820/10152534320660820/?type=1&theater
- Bibliography
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External links
Wikimedia Commons has media related to RL10. |