Helicon plasma thrusters (HPT) feature a cylindrical plasma source where a neutral gas is ionized and heated through helicon waves, followed by a magnetic nozzle that accelerates the plasma into a high-velocity jet. These thrusters are both robust and simple, as they operate without exposed electrodes in direct contact with the plasma. Our research focuses on modeling and simulating plasma transport within the helicon source and its interaction with waves using our in-house HELFLU and HELWAVE codes. Recently, we developed the HPT-05 prototype in collaboration with SENER Ingeniería y Sistemas.

The operation of a plasma thruster generates an energetic plasma plume that expands into space. The outer regions of this plume can lead to contamination and erosion of exposed spacecraft components, as well as influence its electrical charging state. These effects can pose significant challenges for modern telecommunication satellites. To investigate plasma plumes and their interaction with the surrounding environment, we have developed the two-fluid EASYPLUME code and the 3D hybrid PIC/FLUID EP2PLUS code.

Hall Effect Thrusters (HET) are among the most advanced and widely used electric propulsion systems. They consist of an annular channel with a magnetic circuit that generates a predominantly radial magnetic field. By applying a voltage difference across the channel, electrons are constrained to closed drift orbits, leading to efficient ionization of neutral atoms before reaching the anode at the propellant injection side. The restricted axial mobility of electrons also creates a strong axial electric field that accelerates the ions. Our research group has been actively modeling and studying these thrusters for over two decades, developing highly advanced simulation tools. Building on this expertise, we aim to design and test a fully functional HET in the near future.

Electromagnetic waves exhibit fundamentally different behavior in plasma compared to a vacuum, with various wave types emerging depending on frequency, plasma density, and the background magnetic field. Similar to helicon waves in helicon plasma thrusters, electron-cyclotron resonance (ECR) is an efficient heating mechanism that has been proposed for a novel type of plasma thruster—the ECR plasma thruster. As part of the H2020 MINOTOR project, our group is developing a comprehensive simulation framework to model all key processes in this device. Additionally, the study of plasma-wave interactions presents synergies between both thruster technologies.

A magnetic nozzle is a convergent-divergent magnetic field that channels and accelerates a plasma jet to supersonic speeds, generating magnetic thrust. Unlike solid nozzles, magnetic nozzles operate without direct contact, preventing plasma-wall interactions, and can be dynamically adjusted in shape and strength during flight. This adaptability enables features such as thrust vector control without requiring moving parts. The DIMAGNO two-fluid code, developed during my PhD thesis, serves as a valuable simulation tool for studying these systems. Recently, we patented a 3D magnetic nozzle capable of steering the plasma jet in any direction.

To experimentally characterize the plasma in electric propulsion devices, the development of precise plasma diagnostic tools is essential. The EP2 group is actively involved in both the modeling and experimental testing of various diagnostic instruments, including Langmuir probes, emissive probes, Faraday cups, magnetic field sensors, and thrust balances, among others.

Nanosatellites are revolutionizing space technology due to their compact size and cost-effectiveness. They provide an affordable platform for testing new technologies in space and conducting short-duration missions of low to medium complexity. The NanoStar project aims to establish a network of European universities dedicated to designing, building, and launching nanosatellites for educational purposes. This work requires both a broad systems-level perspective of the nanosatellite and specialized expertise in its various subsystems.

After more than 50 years of space activity, Low Earth Orbit (LEO) and Geostationary Orbit (GEO) have become increasingly cluttered with defunct satellites, fragments, and spent rocket stages. Major collision events have already occurred, and the International Space Station (ISS) frequently performs debris-avoidance maneuvers to mitigate potential threats. As part of the FP7 LEOSWEEP project, we explored an innovative approach to addressing the space debris issue: the Ion Beam Shepherd (IBS). This concept utilizes a directed plasma plume to efficiently and contactlessly push debris, guiding it toward atmospheric reentry for safe disposal.

Hall Effect Thrusters (HET) are among the most advanced and widely used electric propulsion systems. They consist of an annular channel with a magnetic circuit that generates a predominantly radial magnetic field. By applying a voltage difference across the channel, electrons are constrained to closed drift orbits, leading to efficient ionization of neutral atoms before reaching the anode at the propellant injection side. The restricted axial mobility of electrons also creates a strong axial electric field that accelerates the ions. Our research group has been actively modeling and studying these thrusters for over two decades, developing highly advanced simulation tools. Building on this expertise, we aim to design and test a fully functional HET in the near future.

Faculty

• Eduardo Ahedo
• Mario Merino
• Pablo Fajardo
• Jaume Navarro Cavallé
• Jiewei Zhou

Associated Members

• Adrián Domínguez Vázquez
• Victor Tribaldos
• José Miguel Reynolds Barredo
• Luis Raúl Sánchez Fernández
• Miguel Pérez Encinar

Post Doc

• Marco Riccardo Inchingolo
• Jesús Perales Díaz
• Alberto Marín Cebrián

PhD Students

• Tatiana Perrotin
• Célian Boyé
• Diego García Lahuerta
• Francisco de Borja de Saavedra Garcia del Río
• David Villegas Prados
• Victor Gómez García
• Borja Bayón Buján
• Matteo Guaita
• Davide Poli
• Matteo Ripoli
• Andrés Rabuñal Gayo
• Simone Dalle Fabbriche
• Guillermo Cuerva Lazaro

Alumni

• Filippo Cichocki
• Daniel Pérez Grande
• Sara Correyero
• Álvaro Sánchez Villar
• Mick Wijnen
• Enrique Bello Benítez
• Pedro Jiménez Jiménez
• Davide Maddaloni

ZARATHUSTRA:

• Revolutionizing advanced electrodeless plasma thrusters for space transportation (2021–2025): European Research Council, ERC-Starting Grant program. Grant number: 950466. Principal Investigator: Mario Merino.

CHEOPS:

• Consortium for Hall Effect Orbital Propulsion System – Phase 2 covering LOW POWER and MEDIUM POWER needs (2021-2024): H2020 Programme (European Commission). Grant number: 101004331. Principal Investigator: Pablo Fajardo, Eduardo Ahedo. Project Manager: SAFRAN-Snecma (France).

SUPERLEO:

• Sustainable propellants enabling plasma propulsion at very low Earth orbit (2022–2024): Grant TED2021-132484B-I00 funded by MCIN/AEI/10.13039/501100011033 and by the “European Union NextGenerationEU/PRTR. Principal Investigator: Jaume Navarro, Pablo Fajardo.

ASPIRE:

• Advanced Space Propulsion for Innovative Realization of space Exploration (2021–2023): H2020 Programme (European Commission). Grant number: 101004366. Principal Investigator: Eduardo Ahedo

EDDA:

• European Direct-Drive Architecture (2019–2021):

  H2020 Programme (European Commission). Grant number: 870470. Principal Investigator: Eduardo Ahedo. Project Manager: Thales Alenia Space (France). Click here for the final version of EDDA leaflet

EXOPLAWIN:

• Estudio de la interacción del viento estelar con magnetosferas exo-planetarias mediante fuentes de plasma artificial y modelos computacionales (2022–2023): Comunidad Autónoma de Madrid (CAM). Grant: EXOPLAWIN-CM-UC3M. Principal Investigator: Jaume Navarro, Jacobo Varela.

ESPEOS:

• Electric Space Propulsion for Earth Orbit Satellites (2020–2022): Ministry of Science and Innovation, National I+D plan, Spanish Government. Grant number: PID2019-108034RB-I00. Principal Investigators: Mario Merino, Pablo Fajardo.

ECOMODIS:

• Electron cooling model for simulation of ep induced plasma interactions with satellites (2022–2024): European Space Agency (ESA). Grant: 4000137869. Principal Investigator: Pablo Fajardo, Eduardo Ahedo.

HIPATIA:

• Helicon Plasma Thruster for In-space Applications (2019–2022): H2020 Programme (European Commission). Grant number: 870542. Principal Investigator: Pablo Fajardo. Project Manager: SENER Aerospace (Spain).

PROMETEO:

• Plasma Propulsion and Nuclear Fusion: innovating space transport (2019–2021): Comunidad Autónoma de Madrid (CAM). Grant number: Y2018/NMT4750. Principal Investigator: Eduardo Ahedo.

COMIT:

• COmpact MIni plasma Thruster for New Space applications (2021–2023): Ministry of Science and Innovation, National I+D plan, Spanish Government. Grant number: PDC2021-120911-I00. Principal Investigator: Eduardo Ahedo, Pablo Fajardo.

Electric propulsion diagnostic for plasma thrusters:

• Electric propulsion diagnostic for plasma thrusters (2021–2022): H2020 Programme (European Commission). Grant number: 101004331. Principal Investigator: Pablo Fajardo, Eduardo Ahedo. Project Manager: SAFRAN-Snecma (France).

MARTINLARA:

• Millimeter wave Array at Room Temperature for INstruments in Leo Altitude Radio Astronomy (2019-2022): Comunidad Autónoma de Madrid (CAM). Grant: P2018/NMT-4333. Principal Investigator: Eduardo Ahedo.

• J. Perales-Diaz, «Fluid-kinetic models for space plasma thrusters«, in , (2024, Universidad Carlos III de Madrid)  [LINK]
• P. Jiménez-Jiménez, «Analysis of the wave-plasma interaction in electrodeless plasma thrusters«, in , (2024, Universidad Carlos III de Madrid)  [LINK]
• M. Inchingolo, «Design, development, and characterization of a microwave electrodeless plasma thruster«, in , (2024, Universidad Carlos III de Madrid)  [LINK]
• E. Bello, «Analysis of turbulent transport in Hall-effect plasma thrusters«, in , (2024, Universidad Carlos III de Madrid)  [LINK]
• M. Wijnen, «Diagnostic Methods for the Characterization of a Helicon Plasma Thruster«, in , (2023, Universidad Carlos III de Madrid)  [LINK]
• A. Sánchez-Villar, «Modeling and simulation of the plasma discharge in an electron cyclotron resonance thruster«, in , (2022, Universidad Carlos III de Madrid)  [LINK]
• J. Zhou, «Modeling and simulation of the plasma discharge in a radiofrequency thruster«, in , (2021, Universidad Carlos III de Madrid)  [LINK]
• S. Correyero Plaza, «Physics of plasma plumes accelerated by magnetic nozzles: an experimental and theoretical research«, in , (2020, Universidad Carlos III de Madrid)  [PDF]
• A. Domínguez-Vázquez, «Axisymmetric simulation codes for Hall effect thrusters and plasma plumes«, in , (2019, Universidad Carlos III de Madrid)  [PDF]
• D. Pérez Grande, «Fluid modeling and simulation of the electron population in Hall Effect Thrusters with complex magnetic topologies«, in , (2018, Universidad Carlos III de Madrid)  [PDF]
• B. Tian, «Modeling of Physical Processes in Radio-frequency Plasma Thrusters«, in , (2017, Universidad Carlos III de Madrid)  [PDF]
• F. Cichocki, «Analysis of the expansion of a plasma thruster plume into vacuum«, in , (2017, Universidad Carlos III de Madrid)  [LINK]
• J. Navarro-Cavallé, «Plasma Simulation in Space Propulsion: the Helicon Plasma Thruster«, in , (2017, Universidad Politécnica de Madrid)  [LINK]
• X. Chen, «Low Work-Function Thermionic Emissionand Orbital-Motion-Limited Ion Collection at Bare-Tether Cathodic Contact«, in , (2015, Universidad Politécnica de Madrid)  [PDF]