XRS-2200 linear aerospike engine for the X-33 program being tested The aerospike engine is a type of rocket engine that maintains its aerodynamic efficiency across a wide range of altitudes through the use of an aerospike nozzle. For this reason the nozzle is sometimes referred to as an altitude-compensating nozzle. A vehicle with an aerospike engine uses 25–30% less fuel at low altitudes, where most missions have the greatest need for thrust. Aerospike engines have been studied for a number of years and are the baseline engines for many single-stage-to-orbit (SSTO) designs and were also a strong contender for the Space Shuttle main engine. However, no engine is in commercial production. The best large-scale aerospikes are still only in testing phases. Image File history File links Size of this preview: 762 × 600 pixel Image in higher resolution (1500 × 1181 pixel, file size: 811 KB, MIME type: image/jpeg) Testing of Twin Linear Aerospike XRS-2200 Engine (noise removed, downsampled) File links The following pages on the English Wikipedia link to this...
Image File history File links Size of this preview: 762 × 600 pixel Image in higher resolution (1500 × 1181 pixel, file size: 811 KB, MIME type: image/jpeg) Testing of Twin Linear Aerospike XRS-2200 Engine (noise removed, downsampled) File links The following pages on the English Wikipedia link to this...
The X-33 was a technology demonstrator for NASAs next-generation of space launch vehicle. ...
A cold (un-ignited) rocket engine test at NASA A rocket engine is a reaction engine that can be used for spacecraft propulsion as well as terrestrial uses, such as missiles. ...
Aerodynamics is a branch of fluid dynamics concerned with the study of gas flows, first analysed by George Cayley in the 1800s. ...
Altitude is the elevation of an object from a known level or datum. ...
Thrust is a reaction force described quantitatively by Newtons Second and Third Laws. ...
A single-stage to orbit (or SSTO) launcher describes an as-yet theoretical class of spacecraft designed to place a load into orbit as a self-contained vehicle without the use of multiple stages. ...
Space Shuttle Main Engine cluster The Space Shuttle Main Engines (SSMEs) are the three main engines on the Space Shuttle orbiter. ...
The terminology in the literature surrounding this subject is somewhat confused — the term aerospike originally was used for a (very roughly conically tapering) truncated plug nozzle with some gas injection to form an 'air spike' to help make up for the absence of the tail of the plug. However, frequently, a full-length plug nozzle is now described as being an aerospike. The plug nozzle is a type of rocket nozzle that, unlike traditional designs, maintains its efficiency at a wide range of altitudes. ...
Variations
 Annular aerospike test firing Several versions of the design exist, differentiated by their shape. In the toroidal aerospike the spike is bowl-shaped with the exhaust exiting in a ring around the outer rim. In theory this requires an infinitely long spike for best efficiency, but by blowing a small amount of gas out the center of a shorter truncated spike, something similar can be achieved. In the linear aerospike (
see picture at top) the spike consists of a tapered wedge-shaped plate, with exhaust exiting on either side at the "thick" end. This design has the advantage of being stackable, allowing several engines to be placed in a row to make one larger engine while augmenting steering performance with the use of individual engine throttle control. Annular aerospike test firing. ...
Annular aerospike test firing. ...
Image File history File links Download high resolution version (3000x2361, 6291 KB) Testing of Twin Linear Aerospike XRS-2200 Engine Description: The test of twin Linear Aerospike XRS-2200 engines, originally built for the X-33 program, was performed on August 6, 2001 at NASAs Stennis Space Center, Mississippi. ...
Principles
It is like and unlike a bell engine. A normal rocket engine uses a large engine bell to direct the jet of exhaust from the engine to the surrounding airflow and maximize its acceleration – and thus the thrust. However, the proper design of the bell varies with external conditions: one that is designed to operate at high altitudes where the air pressure is lower needs to be much larger than one designed for low altitudes. The losses of using the wrong design can be significant. For instance the Space Shuttle engine can generate an exhaust velocity of just over 4,400 m/s in space, but only 3,500 m/s at sea level. If a large bell (designed for high altitude operation) were used near sea level, the extra weight of the bell might not overcome the additional thrust gained. Tuning the bell to the average environment in which the engine will operate is an important task in any rocket design. Image File history File links Size of this preview: 697 × 599 pixelsFull resolution (3030 × 2606 pixel, file size: 293 KB, MIME type: image/gif) A X-33 engine comparison, with a traditional bell engine. ...
Image File history File links Size of this preview: 697 × 599 pixelsFull resolution (3030 × 2606 pixel, file size: 293 KB, MIME type: image/gif) A X-33 engine comparison, with a traditional bell engine. ...
For the current Space Shuttle mission, see STS-117 NASAs Space Shuttle, officially called Space Transportation System (STS), is the United States governments current manned launch vehicle. ...
Space Shuttle Main Engine cluster The Space Shuttle Main Engines (SSMEs) are the three main engines on the Space Shuttle orbiter. ...
The specific impulse (commonly abbreviated Isp) of a propulsion system is the impulse (change in momentum) per unit of propellant. ...
Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector), defined by distance in metres divided by time in seconds. ...
The aerospike attempts to avoid this problem. Instead of firing the exhaust out of a small hole in the middle of a bell, it is fired along the outside edge of a wedge-shaped protrusion, the "spike". The spike forms one side of a virtual bell, with the other side being formed by the airflow past the spacecraft – thus the aero-spike.
The idea behind the aerospike design is that at low altitude the ambient pressure compresses the wake against the nozzle. The recirculation in the base zone of the wedge can then raise the pressure there to near ambient. Since the pressure on top of the engine is ambient, this means that base gives no overall thrust (but it also means that this part of the nozzle doesn't lose thrust by forming a partial vacuum, thus the base part of the nozzle can be ignored at low altitude).
As the spacecraft climbs to higher altitudes, the air pressure holding the exhaust against the spike decreases. This allows the exhaust to move further from the spike, and the base pressure drops, but the recirculation zone keeps the pressure on the base up to a fraction of 1 bar, a pressure that is not balanced by the near vacuum on top of the engine; this difference in pressure thus gives extra thrust at altitude, giving the altitude compensating effect (effectively increasing the size of the nozzle at altitude by the area of the base). The bar (symbol bar), decibar (symbol dbar) and the millibar (symbol mbar, also mb) are units of pressure. ...
In theory the aerospike is slightly less efficient than a bell designed for any given fixed altitude, yet it outperforms that same bell at almost all other altitudes. The difference can be considerable, with typical designs claiming over 90% efficiency at all altitudes.
The disadvantages of aerospikes seem to be extra weight for the spike, and increased cooling requirements due to the extra heated area. Further, the larger cooled area can reduce performance below theoretical levels by reducing the pressure against the nozzle.
Performance Rocketdyne conducted a lengthy series of tests in the 1960s on various designs. Later models of these engines were based on their highly reliable J-2 engine machinery and provided the same sort of thrust levels as the conventional engines they were based on; 200,000 lbf (890 kN) in the J-2T-200k, and 250,000 lbf (1.1 MN) in the J-2T-250k (the T refers to the toroidal combustion chamber). Thirty years later their work was dusted off again for use in NASA's X-33 project. In this case the slightly upgraded J-2S engine machinery was used with a linear spike, creating the XRS-2200. After more development and considerable testing, this project was cancelled when the X-33's composite fuel tanks repeatedly failed. F-1 rocket engine Rocketdyne is a United States company that designs and produces rocket engines that use liquid propellants. ...
J-2 Rocket Engine Specifications. ...
The pound-force is a non-SI unit of force or weight (properly abbreviated lbf or lbf). The pound-force is equal to a mass of one pound multiplied by the standard acceleration due to gravity on Earth (which is defined as exactly 9. ...
The newton (symbol: N) is the SI unit of force. ...
The National Aeronautics and Space Administration (NASA) is an agency of the United States federal government, responsible for the nations public space program. ...
The X-33 was a technology demonstrator for NASAs next-generation of space launch vehicle. ...
Three XRS-2200 engines were built during the X-33 program and underwent testing at NASA's Stennis Space Center. The single-engine tests were a success, but the program was halted before the testing for the 2-engine setup could be completed. The XRS-2200 produces 204,420 lbf thrust with an Isp of 339 seconds at sea level, and 266,230 lbf thrust with an Isp of 436.5 seconds in a vacuum. The John C. Stennis Space Center (or SSC), located in Hancock County, Mississippi at the Mississippi/Louisiana border, is NASAs largest rocket engine test facility. ...
Specific impulse (usually abbreviated Isp) is a way to describe the efficiency of rocket and jet engines. ...
Although the cancelling of the X-33 program was a setback for aerospike engineering, it is not the end of the story. A milestone was achieved when a joint academic/industry team from California State University, Long Beach (CSULB) and Garvey Spacecraft Corporation successfully conducted a flight test of a liquid-propellant powered aerospike engine in the Mojave Desert on September 20, 2003. CSULB students had developed their Prospector 2 (P-2) rocket using a 1,000 lbf (4.4 kN) LOX/ethanol aerospike engine. California State University, Long Beach (also known as Long Beach State, Cal State Long Beach, CSULB, LBSU or The Beach) is the second largest campus of the California State University system and the third largest university in the state of California in terms of enrollment. ...
For the indigenous American tribe, see Mohave. ...
is the 263rd day of the year (264th in leap years) in the Gregorian calendar. ...
Year 2003 (MMIII) was a common year starting on Wednesday (link displays 2003 calendar) of the Gregorian calendar. ...
 Toroidal aerospike nozzle Small-scale aerospike engine development using a hybrid rocket propellant configuration has been ongoing by members of the Reaction Research Society. Another new aerospace research and development group called StoffelCorp Aerospace had recently developed and static tested an aerospike nozzle hybrid rocket configuration with success [July 2006]. Further aerospike hybrid rocket motor tests are scheduled for 2007. Image File history File links Non-truncated toroidal aerospike nozzle used to propel a solid-fuel rocket to 26,000ft at NASAs Dryden Research centre in March 2004 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Image File history File links Non-truncated toroidal aerospike nozzle used to propel a solid-fuel rocket to 26,000ft at NASAs Dryden Research centre in March 2004 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
A hybrid rocket propulsion system comprises propellants of two different states of matter, the most common configuration being a rocket engine composed of a solid propellant lining a combustion chamber into which a liquid or gaseous propellant is injected so as to undergo a strong exothermic reaction to produce hot...
Based in the Southern California desert, the Reaction Research Society is the oldest continuously operating amateur experimental rocket group in the United States. ...
Further progress came in March 2004 when two successful tests were carried out at the NASA Dryden Flight Research Centre using small-scale rockets manufactured by Blacksky Corporation, based in Carlsbad, California. The two rockets were solid-fuel powered and fitted with non-truncated toroidal aerospike nozzles. They reached an apogee of 26,000 ft and speeds of about Mach 1.5. Location of Carlsbad within San Diego County, California. ...
An F/A-18 Hornet breaking the sound barrier. ...
RS-2200 The RS-2200 is the design for the larger aerospike engine derived from the XRS-2200. The RS-2200 was to power the VentureStar single-stage-to-orbit vehicle. In the latest design, seven RS-2200s producing 542,000 pounds of thrust each would boost the VentureStar into low earth orbit. The development on the RS-2200 was formally halted in early 2001 when the X-33 program did not receive Space Launch Initiative funding. Lockheed Martin chose to not continue the VentureStar program without any funding support from NASA. VentureStar VentureStar was Lockheed-Martins proposed design for a SSTO RLV. The programs primary goal was to develop a reusable unmanned space plane for launching satellites into orbit at about 1/10 the cost of other systems that would completely replace the space shuttle. ...
A single-stage to orbit (or SSTO) launcher describes an as-yet theoretical class of spacecraft designed to place a load into orbit as a self-contained vehicle without the use of multiple stages. ...
The X-33 was a technology demonstrator for NASAs next-generation of space launch vehicle. ...
The Space Launch Initiative was a NASA and U.S. Department of Defense joint research and technology project to determine the requirements to meet all the nation’s hypersonics, space launch and space technology needs. ...
Lockheed/BAE/Northrop F-35 Lockheed Trident missile C-130 Hercules; in production since the 1950s, now as the C-130J Lockheed Martin (NYSE: LMT) is an aerospace manufacturer formed in 1995 by the merger of Lockheed Corporation with Martin Marietta. ...
Additional images RS-2200 linear aerospike test firing Linear aerospike test firing. ...
| CSULB aerospike engine Download high resolution version (1600x1200, 144 KB) aerospike engine close up from http://www. ...
California State University, Long Beach (also known as Long Beach State, Cal State Long Beach, CSULB or LBSU) is the largest campus of the California State University system located in Long Beach, California, at the southern coastal tip of Los Angeles County. ...
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See also The expanding nozzle is a type of rocket nozzle that, unlike traditional designs, maintains its efficiency at a wide range of altitudes. ...
LASRE is NASAs Linear Aerospike SR-71 Experiment which took place at the Dryden Flight Research Center at Edwards Air Force Base, California and concluded November 1998. ...
Two N1 Moon rockets appear on the pads at Baikonur Cosmodrome in early July 1969. ...
The Roton was a launch vehicle design for a cone-shaped single-stage-to-orbit (SSTO) fully reusable manned spacecraft. ...
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