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D. Garcia-Alminana

Publications and source records attributed to D. Garcia-Alminana.

2 recordsLinked to original sources

Development and analysis of novel mission scenarios based on Atmosphere-Breathing Electric Propulsion (ABEP)

Operating satellites in Very Low Earth Orbit (VLEO) benefits the already expanding New Space industry in applications including Earth Observation and beyond. However, long-term operations at such low altitudes require propulsion systems to compensate for the large aerodynamic drag forces. When using conventional propulsion systems, the amount of storable propellant limits the maximum mission lifetime. The latter can be avoided by employing Atmosphere-Breathing Electric Propulsion (ABEP) system, which collects the residual atmospheric particles and uses them as propellant for an electric thruster. Thus, the requirement of on-board propellant storage can ideally be nullified. At the Institute of Space Systems (IRS) of the University of Stuttgart, an intake, and a RF Helicon-based Plasma Thruster (IPT) for ABEP system are developed within the Horizons 2020 funded DISCOVERER project. In order to assess possible future use cases, this paper proposes and analyzes several novel ABEP based mission scenarios. Beginning with technology demonstration mission in VLEO, more complex mission scenarios are derived and discussed in detail. These include, amongst others, orbit maintenance around Mars as well as refuelling and space tug missions. The results show that the ABEP system is not only able to compensate drag for orbit maintenance but also capable of performing orbital maneuvers and collect propellant for applications such as Space Tug and Refuelling. Thus, showing a multitude of different future mission applications.

physics.space-ph↗

In-Orbit Aerodynamic Coefficient Measurements using SOAR (Satellite for Orbital Aerodynamics Research)

The Satellite for Orbital Aerodynamics Research (SOAR) is a CubeSat mission, due to be launched in 2021, to investigate the interaction between different materials and the atmospheric flow regime in very low Earth orbits (VLEO). Improving knowledge of the gas-surface interactions at these altitudes and identification of novel materials that can minimise drag or improve aerodynamic control are important for the design of future spacecraft that can operate in lower altitude orbits. Such satellites may be smaller and cheaper to develop or can provide improved Earth observation data or communications link-budgets and latency. Using precise orbit and attitude determination information and the measured atmospheric flow characteristics the forces and torques experienced by the satellite in orbit can be studied and estimates of the aerodynamic coefficients calculated. This paper presents the scientific concept and design of the SOAR mission. The methodology for recovery of the aerodynamic coefficients from the measured orbit, attitude, and in-situ atmospheric data using a least-squares orbit determination and free-parameter fitting process is described and the experimental uncertainty of the resolved aerodynamic coefficients is estimated. The presented results indicate that the combination of the satellite design and experimental methodology are capable of clearly illustrating the variation of drag and lift coefficient for differing surface incidence angle. The lowest uncertainties for the drag coefficient measurement are found at approximately 300 km, whilst the measurement of lift coefficient improves for reducing orbital altitude to 200 km.

physics.space-ph↗