TEPREL is a family of

rocket engine A rocket engine is a reaction engine, producing thrust in accordance with Newton's third law by ejecting reaction mass rearward, usually a high-speed Jet (fluid), jet of high-temperature gas produced by the combustion of rocket propellants stor ...

s designed and built by the Spanish aerospace company

PLD Space Payload Aerospace S.L. (PLD Space) is a Spanish company developing two partially-reusable launch vehicles called Miura 1 and Miura 5. Miura 1 is designed as a sounding rocket for sub-orbital flights to perform research or technology development i ...

for their

Miura 1 Miura 1 (previously called Arion 1) is a suborbital recoverable launch vehicle developed by the Spanish company PLD Space. It is the first launch vehicle in Europe that is designed to be recoverable. It was first launched successfully on October ...

and

Miura 5 Miura 5 is a two-stage European orbital Reusable launch system, recoverable launch vehicle currently under development by the Spanish company PLD Space. In a standard two-stage configuration, it will have a length of 34 m, be capable of inserting ...

launch vehicles. The TEPREL engine, named after the Spanish reusable engine program that is financing its development, uses

kerosene Kerosene, or paraffin, is a combustibility, combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in Aviation fuel, aviation as well as households. Its name derives from the Greek (''kērós'') meaning " ...

and

liquid oxygen Liquid oxygen, sometimes abbreviated as LOX or LOXygen, is a clear cyan liquid form of dioxygen . It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an application which is ongoing. Physical ...

as propellants. So far, several versions of this engine, intended to propel

, have been developed and tested on the company's own liquid propulsion test facilities located in

Teruel Teruel () is a city in Aragon, located in eastern Spain, and is also the capital of Teruel (province), Teruel Province. It had a population of 35,900 as of 2022, making it the least populated provincial capital in Spain. It is noted for its har ...

, Spain.

Revisions

In the first versions of the engine the propellants are driven to the engine by using a pressure-fed cycle with

helium Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is ...

. Later versions of the engine (TEPREL-C) incorporate a

turbopump A turbopump is a fluid pump with two main components: a rotodynamic pump and a driving gas turbine, usually both mounted on the same shaft, or sometimes geared together. They were initially developed in Germany in the early 1940s. The most co ...

TEPREL-DEMO

The TEPREL-DEMO engine, originally called NetonVac1, was first tested in 2015. It is a calorimetric engine model, intended to demonstrate combustion stability as well as to acquire relevant information such as ignition and shut-down sequences, pressures and temperatures along the engine, thrust and propellant mass flow rates at different thrust profiles. Additionally, the engine served to test all associated hardware and software at PLD Space Propulsion Test Facilities. The engine is capable to produce a thrust of 28 kN at sea level.

TEPREL-A

With the TEPREL-A engine, first tested in 2017, the company included several design upgrades, such as a new

combustion chamber A combustion chamber is part of an internal combustion engine in which the air–fuel ratio, fuel/air mix is burned. For steam engines, the term has also been used for an extension of the Firebox (steam engine), firebox which is used to allow a mo ...

design, an improved

injector An injector is a system of ducting and nozzles used to direct the flow of a high-pressure fluid in such a way that a lower pressure fluid is Entrainment (hydrodynamics), entrained in the jet and carried through a duct to a region of higher pres ...

geometry and a regenerative cooling system. The later enables the engine to fire for nearly 2 minutes, which is the envisaged nominal functioning duration for the suborbital launch vehicle

. At sea level, the engine produces a thrust of 32 kN.

TEPREL-B

TEPREL-B is the first flight version of the TEPREL engine. Several design improvements have been implemented to reduce the overall weight of the engine. It is equipped with a

thrust vector control Thrust vectoring, also known as thrust vector control (TVC), is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine(s) or motor(s) to control the attitude or angular velocity of the veh ...

system and a

convergent-divergent nozzle A de Laval nozzle (or convergent-divergent nozzle, CD nozzle or con-di nozzle) is a tube which is pinched in the middle, with a rapid convergence and gradual divergence. It is used to accelerate a compressible fluid to supersonic speeds in the a ...

, all regeneratively cooled. In May 2019 the first unit of this model was destroyed during a test. After a long investigation PLD Space concluded that the problem was due to excess pressure during engine start at ignition. PLD Space addressed the issue through a combination of improvements to the launch site infrastructure and procedural improvements. It is currently fully operational. In February 2020, PLD Space successfully completed a 122-second test that allowed it to achieve flight rating. On August 28, 2020,

completed required tests for the thrust vector control system on the Teprel-B rocket engine.

TEPREL-C

Flight version of the TEPREL engine to be used in the

rocket. Initially it was expected to produce 105.5 kN of thrust at sea level. Later expected thrust was increased to 190 kN.

TEPREL-C Vacuum

Version of TEPREL-C adapted to vacuum, and capable of re-ignition in microgravity conditions. Capable of 75 kN of thrust.

References

{{Rocket engines Rocket engines using kerosene propellant Spacecraft propulsion Space program of Spain Rocket engines using the gas-generator cycle