System Modelling of Very Low Earth Orbit Satellites for Earth Observation
N. H. Crisp, P. C. E. Roberts, K. L. Smith, V. T. A. Oiko, V. Sulliotti-Linner, V. Hanessian, G. H. Herdrich, Daniel García-Almiñana, D. Kataria, S. Seminari
备注：
23 pages, 6 figures, Accepted for publication in Acta Astronautica (2021-07-03)
The operation of satellites in very low Earth orbit (VLEO) has been linked to a variety of benefits to both the spacecraft platform and mission design. Critically, for Earth observation (EO) missions a reduction in altitude can enable smaller and less powerful payloads to achieve the same performance as larger instruments or sensors at higher altitude, with significant benefits to the spacecraft design. As a result, renewed interest in the exploitation of these orbits has spurred the development of new technologies that have the potential to enable sustainable operations in this lower altitude range. In this paper, system models are developed for (i) novel materials that improve aerodynamic performance enabling reduced drag or increased lift production and resistance to atomic oxygen erosion and (ii) atmosphere-breathing electric propulsion (ABEP) for sustained drag compensation or mitigation in VLEO. Attitude and orbit control methods that can take advantage of the aerodynamic forces and torques in VLEO are also discussed. These system models are integrated into a framework for concept-level satellite design and this approach is used to explore the system-level trade-offs for future EO spacecraft enabled by these new technologies. A case-study presented for an optical very-high resolution spacecraft demonstrates the significant potential of reducing orbital altitude using these technologies and indicates possible savings of up to 75% in system mass and over 50% in development and manufacturing costs in comparison to current state-of-the-art missions. For a synthetic aperture radar (SAR) satellite, the reduction in mass and cost with altitude were shown to be smaller, though it was noted that currently available cost models do not capture recent commercial advancements in this segment...
Peculiar orbital characteristics of Earth quasi-satellite 469219 Kamo`oalewa: implications for the Yarkovsky detection and orbital uncertainty propagation
Some comments on the recent results about the measurement of the Lense-Thirring effect in the gravitational field of the Earth with the LAGEOS and LAGEOS II satellites
Some comments about a recent paper on the measurement of the general relativistic Lense-Thirring effect in the gravitational field of the Earth with the laser-ranged LAGEOS and LAGEOS II satellites
The impact of the new CHAMP and GRACE Earth gravity models on the measurement of the general relativistic Lense--Thirring effect with the LAGEOS and LAGEOS II satellites
The impact of electron precipitation on Earth's thermospheric NO production and the drag of LEO satellites
Space Research Institute, Austrian Academy of Sciences（奥地利科学院空间研究所）；Technical University, Graz（格拉茨工业大学）；Institute of Astronomy, Russian Academy of Sciences（俄罗斯科学院天文研究所）；National Center of Physics and Mathematics（国家物理数学中心）；Department of Astrophysics, University of Vienna（维也纳大学天体物理系）；Austrian Space Weather Office, GeoSphere Austria（奥地利空间天气办公室，地球系统奥地利）
An assessment of the measurement of the Lense-Thirring effect in the Earth gravity field, in reply to: ``On the measurement of the Lense-Thirring effect using the nodes of the LAGEOS satellites, in reply to ``On the reliability of the so far performed tests for measuring the Lense-Thirring effect with the LAGEOS satellites'' by L. Iorio,'' by I. Ciufolini and E. Pavlis
