The research activities of the Space Tether Group (STG) are focussed on tether modelling, design and analysis of new concepts and missions, dynamics, and new materials for tether applications. The members of the group have more than 10 years of experience on the subject and have participated in several National and European projects, they include the FP7/Space project BETs and the H2020 FET-OPEN project E.T.PACK, which the STG currently coordinates.The STG is part of an European consortium that will develop within the next few years a deorbit kit for post-mission disposal of satellites with TRL 4 based on electrodynamic tether technology. In 2019, STG hosted the Sixth International Conference on Tethers in Space (TiS2019).

The STG is specialized in electrodynamics tethers and the modeling of its interaction with the ambient plasma. Previous and on-going works include a variety of topics like nonlinear wave excitation by using electrodynamic tethers, modelling of current collection and emission using kinetic eulerian solvers, mitigation of dynamic instabilities, optimal mission design in deorbiting scenarios, and a disruptive subclass of electrodynamic tether named the low work-function tether (LWT). Recently, the group has started a new line of research on thermionic materials applied to LWTs and plasma diagnostics.

Research capabilities

Mission Analysis

The STG has developed BETsMA, a friendly software for the preliminary design and analysis of deorbiting missions by using electrodynamic tethers. The code has two modules. The Optimization Module implements the π-algorithm and can be used to find the optimal tether length, width and thickness for a given mission (spacecraft mass and elements of the initial orbit). The Deorbiting Module computes, for a given tether geometry, the deorbiting maneuver and provides key quantities like the deorbit time, and the temporal evolution of the orbital elements, average and maximum electric current, tether temperature and forces, etc. BETsMA v1.0 was developed under the European Commission FP7 Space Project Propellantless deorbiting of Space Debris by bare electrodynamic tethers (BETs, 262972). Its physical models, performance, and result analysis have been upgraded in BETsMA v2.0, which can also simulate low Work-function tethers with different type of cross-sections, tether attitude dynamics, thermal analysis, and contains many others new capabilities. BETsMA v2.0 has been developed, and will be improved within the next few years, under the European Commission H2020 FET Open project Electrodynamic Tether Technology for Passive Consumable-less Deorbit Kit (E.T.PACK, 828902).

Tether Dynamics

The STG has developed simulators of different complexity to study the dynamics of space tethers and has used them to study several tether applications like stalleite deorbiting at the end of life, drag compensation scenarios, among others. It has also expertise on modelling advanced and non-conventional tether concepts. The animation in the right hand side shows the dynamics of a Low Work-Function Tether with a loop shape orbiting in equatorial orbit and the corresponding Poincare section.

Tether-plasma interaction simulators

The STG has background on key topics of plasma physics related to electrodynamic tethers like Langmuir and emissive probe theory and nonlinear wave propagation in magnetized plasmas. The correct modelling of the charge exchange with the plasma is critical for bare tethers because current and voltage profiles along the tether impact on tether performance and dynamics. The group has developed a suit of Vlasov-Poisson solvers that allow a kinetic analysis of the plasma sheath around tethers and the determination of the current collected and emitted by bare and coated tethers. The suit has currently three tools:

• Stationary Vlasov-Poisson solver for cylindrical tethers. Works are currently in progress to construct a database with characterics curves (current versus bias) for cylindrical tethers with and without electron emission to be used in both tether and plasma diagnostics applications.

• Stationary Vlasov-Poisson solver for tape-like tethers. It allows to study the current collection and emission of tethers and probes with an arbitrary cross-section.

• Non-stationary Vlasov-Poisson solver for cylindrical tethers immersed in flowing plasmas. It allows to study advanced effects like the particle trapping during transient phases. An example is given in the animation in the right hand side, which shows the evolution of the electron distribution at two points of the sheath around a positively polarized tether.

 

Competitive research projects

• Early Technology Development Project, “A Consumable-less Propulsion System Based on a Bare-Photovoltaic Tether”, European Space Agency, 175 k€, 2022-2023. PI: Gonzalo Sánchez-Arriaga

• Innovation Launchpad, “Business Model for Maneuvering Kit.”, European Commission, 100 k€, No 101034874, 2021-2022. Coordinator: SENER Aeroespacial, PI: G. Sánchez-Arriaga

• Industrial PhD, UC3M-SENER, Comunidad de Madrid, IND2019/TIC-17198, 90k€, 2019-2023. Grant Holder: S. García González. Advisor: G. Sánchez-Arriaga

• H2020-FET-OPEN project “E.T.PACK: Electrodynamic Tether Technology for Passive Consumable-less Deorbit Kit”
  European Comission, 3M€, No.828902, 2019-2022

• Deorbiting of space debris by electrodynamic tethers
  Ministerio de Economia y Coompetitividad of Spain, 40.000€, 2015-2020

• Europa Investigación ” Consolidation of European Consortium on Space Tethers “
  Ministerio de Economia y Competitividad of Spain, 25k€, 2017. Principal Investigator: G. Sánchez-Arriaga.

• Europa Excelencia ” Manufacturing and Testing of Low Work Function Tethers “
  Ministerio de Economia y Competitividad of Spain, 68k€, 2017-2018. Principal Investigator: G. Sánchez-Arriaga.

• Ramon y Cajal Grant
  Ministerio de Economia y Competitividad of Spain, 308k?€, 2015-2020. Grant holder: G. Sánchez-Arriaga.

• Atracción de Talento
  Comunidad de Madrid, 60k?€, 2019-2023. Grant holder: S. Naghdi.

Recent publications

• Ionospheric Experiment with a Low Work Function Tether Loop
  G. Sánchez-Arriaga and S. Naghdi Journal of Guidance, Control, and Dynamics , (2020)

• Electrical model and optimal design scheme for low work-function tethers in thrust mode
  G. Sánchez-Arriaga and J. R. Sanmartín Aerospace Science and Technology , (2020)

• Orbital Motion Theory and Operational Regimes for Cylindrical Emissive Probes
  X. Chen, G. Sánchez-Arriaga, Physics of Plasmas , (2017)

• Modeling and stability analysis of tethered kites at high-altitudes
  A. Pastor-Rodríguez, G. Sánchez-Arriaga, M. Sanjurjo-Rivo, American Institute of Aeronautics and Astronautics, (2017)

• Optimal Design and Deorbiting Performance of Thermionic Tethers in Geostationary Transfer Orbits
  G. Sánchez-Arriaga, X. Chen, E. Lorenzini, Journal of Propulsion and Power , (2017)

• Modeling and Performance of Electrodynamic Low-Work-Function Tethers with Photoemission Effects
  G. Sánchez-Arriaga, X. Chen, Journal of Propulsion and Power , (2017)

• Comparison of technologies for deorbiting spacecraft from low-earth-orbit at end of mission
  G. Sánchez-Arriaga, J. Sanmartin, E. Lorenzini, Acta Astronautica , (2017)

• Analysis of Tether-Mission Concept for Multiple Flybys of Moon Europa
  J. Sanmartin, M. Charro, H. Garret, G. Sánchez-Arriaga, A. Sanchez-Torres, Journal of Propulsion and Power , (2017)

• Analysis of Thermionic Bare Tether Operation Regimes in Passive Mode
  J. Sanmartin, X. Chen, G. Sánchez-Arriaga, Physics of Plasmas , (2017)

• Impact of nonideal effects on bare electrodynamic tether performance
  G. Sánchez-Arriaga, C. Bombardelli, X. Chen, Journal of Propulsion and Power , (2015)

• Optimum sizing of bare-tape tethers for de-orbiting satellites at end of mission
  J. Sanmartin, A. Sanchez-Torres, S. B. Khan, G. Sánchez-Arriaga, M. Charro, Advances in Space Research , (2015)

• Direct Vlasov simulations of electron-attracting cylindrical Langmuir probes in flowing plasmas
  G. Sánchez-Arriaga, D. Pastor-Moreno, Physics of Plasmas , (2014)

• Efficient Computation of Current Collection in Bare Electrodynamic Tethers in and beyond OML regime
  M. Sanjurjo-Rivo, G. Sánchez-Arriaga, J. Pelaez Alvarez, Journal of Aerospace Engineering , (2014)

• A direct Vlasov code to study the non-stationary current collection by a cylindrical Langmuir probe
  G. Sánchez-Arriaga, NPhysics of Plasmas , (2013)

• Seguridad Espacial: Una solución práctica para el problema de los residuos espaciales en órbita
  G. Sánchez-Arriaga and J. R. Sanmartín, En: “III Seminario sobre Actividades Espaciales y Derecho”, (2013) pp. 19-21

• Relativistic current collection by a cylindrical Langmuir probe
  G. Sánchez-Arriaga and J. R. Sanmartín, Physics of Plasmas , (2012)

• Three-body dynamics and self-powering of an electrodynamic tether in a plasmasphere
  D. Curelli, E.C. Lorenzini, C. Bombardelli , Journal Of Propulsion And Power, (2010)

• Magnetic Pumping Of Whistler Waves By Tether Current Modulation
  G. Sánchez-Arriaga and J. R. Sanmartín, Journal of Geophysical Research , (2010)

• Asymptotic Solution for the Current Profile of Passive Bare Electrodynamic Tethers
  C. Bombardelli, J. Peláez and M. Sanjurjo, Journal Of Propulsion And Power, (2010)

• Generator regime of self-balanced electrodynamic bare tethers
  J. Peláez and M. Sanjurjo, The Aeronautical Journal, (2006)

Conference presentations

• Numerical Analysis of Tape Like Low Work Function Tether Interaction With Ionospheric Plasmas
  L. Chiabó, X. Chen and G. Sanchez-Arriaga, The Sixth International Conference on Tethers in Space, Madrid, (2019)

• The E.T.PACK Project: towards a fully passive and consumable-less deorbit kit based on low work-function tether technology
  G. Sanchez-Arriaga, S. Naghdi, K. Waetzig, J. Schilm, E. Lorenzini, M. Tajmar, E. Urgoiti, L. Tarabini, J. F. Plaza and A. Post, The Sixth International Conference on Tethers in Space , Madrid, (2019)

• Trade-off Analysis of C12A7:e- Deposition Techniques Applied to Low Work Function Tethers
  J. F. Plaza, G. Meiro, A. Post, R. Perez, F. J. Palomares, P. Tejedor, S. Naghdi, A. Várez, X. Chen, J. Navarro and G. Sanchez-Arriaga, The Sixth International Conference on Tethers in Space , Madrid, (2019)

• Work function tuning of graphene oxide by using cesium applied to low work function tethers
  S. Naghdi, A. Várez, X. Chen, J. Navarro, G. Sanchez-Arriaga, J. F. Plaza, G. Meiro and A. Post, The Sixth International Conference on Tethers in Space , Madrid, (2019)

• Customer-driven deorbit kit based on bare electrodynamic tether technology
  E. Urgoiti, L. Tarabini, G. Sanchez-Arriaga, E. Lorenzini, M. Tajmar and J. Marcos, Clean Space Industrial Days , Noordwijk, Holland, (2017)

• Deorbit Kit Based on Low Work-Function Tethers for Cubesats
  G. Sánchez-Arriaga, K. Watzig, E. Lorenzini, M. Tajmar, E. Urgoiti and L. Tarabini, CubeSat Industry Day 2017 , Noordwijk, Holland, (2017)

• Deorbit Kit Based on Low Work-Function Tethers for Cubesats
  G. Sánchez-Arriaga, K. Watzig, E. Lorenzini, M. Tajmar, E. Urgoiti and L. Tarabini, CubeSat Industry Day 2017 , Noordwijk, Holland, (2017)

• Deorbiting kits for cubesats
  X. Geneste, E. Urgoiti, Lorenzo Tarabini, G. Sánchez-Arriaga, E. Lorenzini, M. Tajmar and J. Marcos, CubeSat Industry Day 2017 , Noordwijk, Holland, (2017)

• Propellantless Technology for the Deorbiting of Small Satellites Mega-Constellation at the End of Life
  R. Mantellato, E. Lorenzini, G. Sánchez-Arriaga, 4S Symposium , Valleta, Malta, (2016)

• BETsMA: A Friendly Tool for Electrodynamic Tether Mission Design
  G. Sánchez-Arriaga and X. Chen, International Conference on Tethers in Space , Ann Arbor, United States of America, (2016)

• Comparison of Technologies for de-orbiting spacecraft from Low-Earth-Orbit
  G. Sánchez-Arriaga, J. Sanmartín and E. Lorenzini, International Conference on Tethers in Space , Ann Arbor, United States of America, (2016)

• Deorbit with bare tether system from high eccentricity initial orbit:analyses and numerical simulation
  G. Pastore, E. Lorenzini and G. Sánchez-Arriaga, International Conference on Tethers in Space , Ann Arbor, United States of America, (2016)

• Analysis of thermionic bare tether operation regimes in passive mode
  J. Sanmartin, X. Chen and G. Sánchez-Arriaga, 14th Spacecraft Charging Technology Conference , Noordwijk, Holland, (2016)

• Electrodynamic tethers fundamentals
  G. Sánchez-Arriaga, Science And Technology Challenges Of Space Debris Removal And Asteroid Deflection , Santander, Spain, (2015)

• End of life disposal of spacecraft with electrodynamic tethers
  G. Sánchez-Arriaga, Science And Technology Challenges Of Space Debris Removal And Asteroid Deflection , Santander, Spain, (2015)

• Lecture on Propellantless Propulsion: Bare Electrodynamic tethers
  G. Sánchez-Arriaga and M. Sanjurjo-Rivo, Lecture on Propellantless Propulsion , Holland, (2015)

• Life Deorbiting Services for Microsatellites Making Use of Bare Electrodynamic Tethers
  R. Mantellato, A. Valmorbida, M. Pertile, A. Francesconi, E. Lorenzini and G. Sánchez-Arriaga, Small Satellite Systems and Services Symposyum, , Palma de Mallorca, (2014 )

• Tape-tether design for the de-orbiting from given altitude and inclination
  J. R. Sanmartin Losada, A. Sánchez Torres, S. Bayajid Khan, G. Sánchez-Arriaga and M. Charro Cubero. 6th European Conference on Space Debris , Darmstadt, Germany, (2013)

• Eliminación de basura espacial
  G. Sánchez-Arriaga, European Space Expo , Madrid, Spain, (2013)

• Propellantless deorbiting of space debris by bare electrodynamic tethers
  J. R. Sanmartin Losada, G. Sánchez-Arriaga, E. Lorenzini, D. Zanutto, J. F. Roussel, P. Sarrailh, J. D. Williams, K. Xie, F. Garcia de Quiros, J. Carrasco, T. van Zoest, R. Rosta, J. Lasa and J. Marcos. 2nd FP7 Space Conference , Larnaca, Chipre, (2012)

• A corrected tether-mission to Jupiter
  G. Sánchez-Arriaga, M. Charro Cubero, J. R. Sanmartin Losada. European Planetary Science Congress 2012 , Madrid, Spain, (2012)

• BETs progress in state-of-the-art tether technology
  J. R. Sanmartin Losada, G. Sánchez-Arriaga, E. Lorenzini, et. al. CleanSpace Workshop (ESA/ESOC) , Darmstadt, Germany, (2012)

• In-orbit experiment on parametric pumping low frequency waves by tether-current modulation
  G. Sánchez-Arriaga and J. R. Sanmartin Losada. 37th Committee on Space Research (COSPAR) Sciencific Assembly , Montréal, Canada, (2008)

PhD Theses

• Emissive Langmuir Probe Theory with Application to Low Work Function Electrodynamic Tethers
  L. Chiabò. Director: G. Sánchez-Arriaga. On-going Thesis

• Modelling and Mission Analysis of Low Work-Function Tethers
  S. Shahsavani. Director: G. Sánchez-Arriaga. On-going Thesis

• Project title: Bare-Tether Cathodic Contact through Thermionic Emission by Low-W Materials
  X. Chen. Directors: J. R. Sanmartin Losada and G. Sánchez-Arriaga. UC3M, (2015)

• Bare-tape scaling laws for de-orbit missions in a space debris environment
  S. Bayajid Khan. Directors: J. R. Sanmartin Losada and G. Sánchez-Arriaga. UC3M, (2014)

Bachelor and Master Theses

• Trade-off Analysis of Distribution Function Mapping Algorithms in Stationary Vlasov-Poisson Solvers
  Alejandro Penacho Riveiros: L. Chiabò, UC3M, (2020)

• A Robust Dynamical Model of a Flexible Space Tether
  Gabriel de Haro Pizarroso: G. Sánchez-Arriaga, UC3M, (2020)

• Analysis of Collision Probability of Electrodynamic Tethers in Deorbiting Scenarios
  Leyre Hernandez Palacios: G. Sánchez-Arriaga, UC3M, (2020)

• Preliminary mission design of payload adapters deorbiting using electrodynamic tethers
  Mikhail Bezdenjnykh Vasenin: G. Sánchez-Arriaga, UC3M, (2014)