A ramjet, is a form of airbreathing jet engine that uses the forward motion of the engine to take in air for combustion that produces jet thrust. Since it produces no thrust when stationary, ramjet-powered vehicles require an assisted take-off like a rocket assist to accelerate it to a speed where it begins to produce thrust. Ramjets work most efficiently at supersonic speeds around Mach 3 and can operate up to speeds of Mach 6.
A tripropellant rocket is a rocket that uses three propellants, as opposed to the more common bipropellant rocket or monopropellant rocket designs, which use two or one propellants, respectively. Tripropellant systems can be designed to have high specific impulse and have been investigated for single-stage-to-orbit designs. While tripropellant engines have been tested by Rocketdyne and Energomash, no tripropellant rocket has been flown.
A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other.
A liquid air cycle engine (LACE) is a type of spacecraft propulsion engine that attempts to increase its efficiency by gathering part of its oxidizer from the atmosphere. A liquid air cycle engine uses liquid hydrogen (LH2) fuel to liquefy the air.
A liquid-propellant rocket or liquid rocket utilizes a rocket engine that uses liquid propellants. Gaseous propellants may also be used but are not common because of their low density and difficulty with common pumping methods. Liquids are desirable because they have a reasonably high density and high specific impulse (Isp). This allows the volume of the propellant tanks to be relatively low. The rocket propellants are usually pumped into the combustion chamber with a lightweight centrifugal turbopump, although some aerospace companies have found ways to use electric pumps with batteries, allowing the propellants to be kept under low pressure. This permits the use of low-mass propellant tanks that do not need to resist the high pressures needed to store significant amounts of gasses, resulting in a low mass ratio for the rocket.
The Lockheed Martin X-33 was a proposed uncrewed, sub-scale technology demonstrator suborbital spaceplane that was developed for a period in the 1990s. The X-33 was a technology demonstrator for the VentureStar orbital spaceplane, which was planned to be a next-generation, commercially operated reusable launch vehicle. The X-33 would flight-test a range of technologies that NASA believed it needed for single-stage-to-orbit reusable launch vehicles, such as metallic thermal protection systems, composite cryogenic fuel tanks for liquid hydrogen, the aerospike engine, autonomous (uncrewed) flight control, rapid flight turn-around times through streamlined operations, and its lifting body aerodynamics.
The Space Shuttle external tank (ET) was the component of the Space Shuttle launch vehicle that contained the liquid hydrogen fuel and liquid oxygen oxidizer. During lift-off and ascent it supplied the fuel and oxidizer under pressure to the three RS-25 main engines in the orbiter. The ET was jettisoned just over 10 seconds after main engine cut-off (MECO) and it re-entered the Earth's atmosphere. Unlike the Solid Rocket Boosters, external tanks were not re-used. They broke up before impact in the Indian Ocean, away from shipping lanes and were not recovered.
The Atlas-Centaur was a United States expendable launch vehicle derived from the SM-65 Atlas D missile. The vehicle featured a Centaur upper stage, the first such stage to use high-performance liquid hydrogen as fuel. Launches were conducted from Launch Complex 36 at the Cape Canaveral Air Force Station (CCAFS) in Florida. After a strenuous flight test program, Atlas-Centaur went on to launch several crucial spaceflight missions for the United States, including Surveyor 1, Mariner 4, and Pioneer 10/11. The vehicle would be continuously developed and improved into the 1990s, with the last direct descendant being the highly successful Atlas II.
The Lockheed CL-1200 Lancer was a late 1960s company-funded proposal for a fighter aircraft based on the Lockheed F-104 Starfighter. The CL-1200 was conceived and marketed mainly for and to non-US military services, as an export product. As such it would have competed with combat-proven designs like the Dassault Mirage III, McDonnell Douglas F-4 Phantom II, Mikoyan-Gurevich MiG-21, and Northrop F-5E Tiger II. The CL-1200 competed unsuccessfully against proposed fourth generation designs, under the US government's Lightweight Fighter program, which would eventually result in the General Dynamics F-16 and Northrop F-17 Cobra.
The precooled jet engine is a concept that enables jet engines with turbomachinery, as opposed to ramjets, to be used at high speeds. Precooling restores some or all of the performance degradation of the engine compressor, as well as that of the complete gas generator, which would otherwise prevent flight with high ram temperatures.
A hydrogen-powered aircraft is an aeroplane that uses hydrogen fuel as a power source. Hydrogen can either be burned in a jet engine or another kind of internal combustion engine, or can be used to power a fuel cell to generate electricity to power an electric propulsor. It cannot be stored in a traditional wet wing, and hydrogen tanks have to be housed in the fuselage or be supported by the wing.
The Convair Kingfish reconnaissance aircraft design was the ultimate result of a series of proposals designed at Convair as a replacement for the Lockheed U-2. Kingfish competed with the Lockheed A-12 for the Project Oxcart mission, and lost to that design in 1959.
The Lockheed NF-104A was an American mixed-power, high-performance, supersonic aerospace trainer that served as a low-cost astronaut training vehicle for the North American X-15 and projected Boeing X-20 Dyna-Soar programs.
Project Isinglass was the code name given to two heavily classified, crewed reconnaissance aircraft studied by the Central Intelligence Agency (CIA) as potential replacements for the Lockheed A-12 and SR-71 during the mid-1960s. The first proposal under the Isinglass name, a high-altitude plane to fly at Mach 4 – Mach 5, was considered an insufficient advancement over existing aircraft; the second, much more advanced design, sometimes referred to as Project Rheinberry, was an air-launched, Mach 20 rocket-powered boost-glide aircraft that would use a very-high-altitude trajectory to avoid defenses. This aircraft was considered too costly for development, and the project was abandoned in 1967.
This is a timeline of the history of hydrogen technology.
The U-1 was a 1950s liquid hydrogen trailer designed to carry cryogenic liquid hydrogen (LH2) on roads being pulled by a powered vehicle. It was designed in response to requirements of the secret US government program code-named Suntan, which aimed to develop a high speed, high altitude hydrogen-powered military aircraft. The trailer was constructed by the Cambridge Corporation and had a capacity of 26,500 liters with a hydrogen loss rate of approximately 2 percent per day.
The pintle injector is a type of propellant injector for a bipropellant rocket engine. Like any other injector, its purpose is to ensure appropriate flow rate and intermixing of the propellants as they are forcibly injected under high pressure into the combustion chamber, so that an efficient and controlled combustion process can happen.
Douglas Aircraft's SASSTO, short for "Saturn Application Single Stage to Orbit", was a single-stage-to-orbit (SSTO) reusable launch system designed by Philip Bono's team in 1967. SASSTO was a study in minimalist designs, a launcher with the specific intent of repeatedly placing a Gemini capsule in orbit for the lowest possible cost. The SASSTO booster was based on the layout of the S-IVB upper stage from the Saturn family, modified with a plug nozzle. Although the SASSTO design was never followed up at Douglas, it is widely referred to in newer studies for SSTO launchers, notably the MBB "Beta" design, which was largely an updated version of SASSTO.
Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines.
The MARC-60, also known as MB-60, MB-XX, and RS-73, is a liquid-fuel cryogenic rocket engine designed as a collaborative effort by Japan's Mitsubishi Heavy Industries and US' Aerojet Rocketdyne. The engine burns cryogenic liquid oxygen and liquid hydrogen in an open expander cycle, driving the turbopumps with waste heat from the main combustion process.
