Fly low, fly propellantless! Air-breathing Electric THrustER www.aether-h2020.eu Grant Agreement Number 870436 What is AETHER? AETHER (Air-breathing Electric THrustER) is an R&D Project aimed at demonstrating the feasibility of the air-breathing Electric Propulsion (EP), otherwise called RAM-EP. AETHER is funded by the European Union under Horizon 2020, SPACE-13-TEC-2019. AETHER is an Operational Grant included in the agenda of the Strategic Research Cluster Electric Propulsion Innovation & Competitiveness (EPIC), aimed at enabling major advances in EP for in-space operations and transportation, to enhance European competitiveness and non-dependence. Grant Agreement Number 870436 Alternative cathode design and development Flow simulations, intake optimization, non-invasive diagnostics Who we are The AETHER team Coordinator, RAM-EP concept design, ionization and Hall-effect acceleration stages development, on-ground system testing Grant Agreement Number 870436 Gridded acceleration stage design and development Mission analysis and optimization Material science studies for harsh environments Evaluation of the atmospheric remnants in VLEO region and definition of other celestial bodies atmospheres What is the goal of an air-breathing satellite? Spacecraft relying on a RAM-EP system are conceived to orbit between 160 km and 250 km from Earth, an orbital region (VLEO, Very Low Earth Orbit) still unexploited. In VLEO remnant gas atoms and molecules from Earth’s atmosphere are available to be possibly used as propellant. A combination of electric and magnetic fields ionizes and accelerates such propellant to give the spacecraft the necessary thrust to counteract atmospheric drag and enable long duration missions. Grant Agreement Number 870436 What is “air-breathing Electric Propulsion”? A propulsion system that uses electrical energy to change the velocity of a satellite, exploiting the residual atmosphere as propellant. A RAM-EP system does not require to store the propellant, whereas it is necessary for conventional propulsion systems. Why use “air-breathing EP”? Giving the fact there is no need of onboard propellant, airbreathing EP can enable long duration missions in VLEO. What are the challenges of “air-breathing EP”? • Complex trade-off @system level • Materials degradation (oxidation, erosion) • Complex on-ground testing Need to develop critical technologies for • Collection of rarefied airflows • Ionization of atmospheric particles • Flow acceleration and neutralization Grant Agreement Number 870436 AETHER goal and tasks The main objective of AETHER is to demonstrate the critical functions of an airbreathing electric propulsion system in a relevant environment and its effectiveness in compensating atmospheric drag. Main tasks are: • Identify specific application cases for the RAM-EP technology and derive system requirements. • Develop critical technologies (including materials) for the collection, ionization and acceleration of rarefied atmospheric flows, and manufacture a RAM-EP system prototype. • Develop and manufacture a representative on-ground test set-up. • Assess the performance of the RAM-EP system by testing. Grant Agreement Number 870436 “Air-breathing” system architecture An air-breathing EP System is basically composed of: An Air-breathing EP thruster on the back, including: • An ionization stage, to ionize the flow gathered by the intake; • An acceleration stage, to accelerate the ionized particles. • A neutralizer, which electrically neutralizes the flow and keeps the spacecraft neutral A frontal intake to collect and compress the rarefied atmospheric flow particles. Grant Agreement Number 870436 Particle collection The frontal intake is in charge of collecting and compressing the flow that feeds the acceleration stage. To reach a good ionization level, a high compression ratio (~100) is required, which typically implies a low collection efficiency (~30%). Optimization Model parametrization Particle’s collection Particle’s compression Grant Agreement Number 870436 Particlesimulation Propellant ionization and acceleration Whilst the ionization stage is a monolithic building block, two acceleration methods are explored within AETHER: CDAS (Closed Drift Acceleration Stage) and CSAS (Charge Separation Acceleration Stage). They derive from Hall Effect Thrusters (HET) and from Gridded Ion Engines (GIE), respectively. Ionization Stage External Neutralizer CDAS Accelerator CSAS Accelerator Internal Cathode (not visible) Internal Cathode / Neutralizer Ionization Stage Grant Agreement Number 870436 Flow neutralization A cathode/neutralizer is needed by the RAM-EP system to produce electrons for the ionization stage, but also for keeping the resulting plasma plume neutral with respect to the spacecraft. In AETHER two technologies are explored for the cathode/neutralizer: Radio Frequency (RF) Cathode (left) and Hollow Cathode (right). Grant Agreement Number 870436 On-ground testing A Particle Flow Generator (PFG) is needed to recreate a flow of ~50% O and 50% N2 with an average velocity of the same order of magnitude of the orbiting velocity in VLEO (~8 km/s). Advanced Diagnostics System for PFG • Thrust Balance • Faraday probes • Fast triple Langmuir probe • Retarding Potential Analyzer • Optical Emission Spectroscopy Faraday Cup Fast Langumuir probe& robotic arm Retarding Potential Analyzer Optical fibre lens and rail Grant Agreement Number 870436 Air-breathing Electric THrustER www.aether-h2020.eu Contact us @ aether@sitael.com Follow us on Facebook or Linkedin Grant Agreement Number 870436