Editing Aerospike engine (section)

==Performance==
<!-- Deleted image removed: [[File:Annular-Aerospike.jpg|thumb|[[Rocketdyne]]'s [[J-2 (rocket engine)|J-2T-250k]] annular aerospike test firing.]] -->
[[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 (rocket engine)|J-2]] engine machinery and provided the same sort of thrust levels as the conventional engines they were based on; 200,000 [[pound-force|lbf]] (890 [[Newton (unit)|kN]]) in the '''J-2T-200k''', and 250,000&nbsp;lbf (1.1 MN) in the '''J-2T-250k''' (the T refers to the toroidal combustion chamber). Thirty years later their work was revived 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 '''[[Rocketdyne XRS-2200|XRS-2200]]'''. After more development and considerable testing, this project was cancelled when the X-33's composite fuel tanks repeatedly failed.
 
[[File:Aerospike close-up.jpg|thumb|[[CSULB]] aerospike engine]]
Three XRS-2200 engines were built during the X-33 program and underwent testing at NASA's [[John C. Stennis Space Center|Stennis Space Center]]. The single-engine tests were a success, but the program was halted before the testing for the two-engine setup could be completed. The XRS-2200 produces {{convert|204420|lbf|abbr=on}} thrust with an [[Specific impulse|I<sub>sp</sub>]] of 339 seconds at sea level, and {{convert|266230|lbf|abbr=on}} thrust with an I<sub>sp</sub> of 436.5 seconds in a vacuum.

The RS-2200 Linear Aerospike Engine<ref>{{cite web|title=RS-2200|url=http://www.astronautix.com/r/rs-2200.html|archive-url=https://web.archive.org/web/20161228055938/http://astronautix.com/r/rs-2200.html|url-status=dead|archive-date=28 December 2016|website=Astronautix.com|access-date=4 February 2018}}</ref> was 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 {{convert|542000|lbf|kN}} 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. An engine of this type is on outdoor display on the grounds of the NASA Marshall Space Flight Center in Huntsville Alabama.

[[File:Non-truncated toroidal aerospike nozzle.jpg|thumb|[[NASA]]'s toroidal aerospike nozzle]]
The [[Lockheed Martin X-33#Cancellation|cancellation of the Lockheed Martin X-33]] by the federal government in 2001 decreased funding availability, but aerospike engines remain an area of active research. For example, 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&nbsp;lb<sub>f</sub> (4.4&nbsp;kN) LOX/ethanol aerospike engine. This work on aerospike engines continues; Prospector-10, a ten-chamber aerospike engine, was test-fired June 25, 2008.<ref>{{Cite web|url=http://www.csulb.edu/colleges/coe/mae/views/projects/rocket/|archive-url=https://web.archive.org/web/20080615154007/http://www.csulb.edu/colleges/coe/mae/views/projects/rocket/|url-status=dead|title=CSULB CALVEIN Rocket News and Events|archive-date=June 15, 2008}}</ref>

[[File:Nozzle performance comparison.svg|thumb|Nozzle performance comparison of [[bell nozzle|bell]] and aerospike nozzle]]

Further progress came in March 2004 when two successful tests sponsored by the NASA [[Dryden Flight Research Center]] using high-power rockets manufactured by [[Blacksky Corporation]], based in [[Carlsbad, California]]. The aerospike nozzles and solid rocket motors were developed and built by the rocket motor division of [[Cesaroni Technology Incorporated]], north of Toronto, Ontario. The two rockets were solid-fuel powered and fitted with non-truncated toroidal aerospike nozzles. Flown at the Pecos County Aerospace Development Center, Fort Stockton, Texas, the rockets achieved apogees of {{convert|26000|ft|m|abbr=on}} and speeds of about [[Mach number|Mach]] 1.5.

Small-scale aerospike engine development using a [[hybrid rocket]] propellant configuration has been ongoing by members of the [[Reaction Research Society]].

In 2020 the [[TU Dresden]] and [[Fraunhofer IWS]] started their CFDμSAT-Project for research on additively manufactured aerospike-engines. A prototype has already been tested in a test cell at TU Dresden's Institute of Aerospace Engineering, achieving a burn time of 30 seconds.<ref>{{cite web|title=TU-Dresden Homepage|url=https://tu-dresden.de/tu-dresden/profil/exzellenz/news/3D-Raketentriebwerk?set_language=en|website=tu-dresden.de|access-date=23 April 2021}}</ref>