Aerospike engine
If the exhaust is allowed to escape in this form, only a small part of the flow will be moving in the correct direction and thus contribute to forward thrust.
In the linear aerospike the spike consists of a tapered wedge-shaped plate, with exhaust exiting on either side at the "thick" end.
An engine of this type is on outdoor display on the grounds of the NASA Marshall Space Flight Center in Huntsville Alabama.
The 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.
[6] 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.
Flown at the Pecos County Aerospace Development Center, Fort Stockton, Texas, the rockets achieved apogees of 26,000 ft (7,900 m) and speeds of about Mach 1.5.
Small-scale aerospike engine development using a hybrid rocket propellant configuration has been ongoing by members of the Reaction Research Society.
[7] In July 2014 Firefly Space Systems announced its planned Alpha launcher that uses an aerospike engine for its first stage.
In March 2017 ARCA Space Corporation announced their intention to build a single-stage-to-orbit (SSTO) rocket, named Haas 2CA, using a linear aerospike engine.
[9] On December 20, 2019, ARCA tested the LAS 25DA aerospike steam rocket engine for the Launch Assist System.
[12] Rocketstar planned to launch its 3D-printed aerospike rocket to an altitude of 50 miles in February 2019 but canceled the mission three days ahead of liftoff citing safety concerns.
[13] In November 2021, Spain-based Pangea Aerospace began hot-fire testing of its small-scale demonstration methane-oxygen aerospike engine DemoP1.
[16] Headquartered in Kent, Washington, Stoke Space is building and testing a distributed architecture LH2/LOX aerospike system for its reusable second stage.
[17] The Bremen-based German startup POLARIS Raumflugzeuge GmbH received a Bundeswehr contract to design and flight test a linear aerospike engine in April 2023.
The company is set to test this new engine on board of its fourth spaceplane demonstrator, DEMO-4 MIRA, in late 2023[18][19] at Peenemünde,[20] where the V-2 rockets were developed.
[21] On 29 October 2024, the company was the first ever to ignite an aerospike engine in a flight over the Baltic Sea, powering a four-engine, kerosene-fueled, turbojet MIRA-II demonstrator.
[25] SpaceFields, incubated at IISc, has successfully tested India's first AeroSpike Rocket Engine at its Challakere facility on 11-Sep-2024.
[26] LEAP 71 a company based in Dubai, successfully hot fired a 5000N Aerospike powered by cryogenic liquid oxygen (LOX) and Kerosene at the test stand of Airborne Engineering in Westcott, UK.
