Impact of the Atmospheric Drag on Starlette, Stella, Ajisai, and Lares Orbits

Abstract The high-quality satellite orbits of geodetic satellites, which are determined using Satellite Laser Ranging (SLR) observations, play a crucial role in providing, e.g., low-degree coefficients of the Earth's gravity field including geocenter coordinates, Earth rotation parameters, as well as the SLR station coordinates. The appropriate modeling of non-gravitational forces is essential for the orbit determination of artificial Earth satellites. The atmospheric drag is a dominating perturbing force for satellites at low altitudes up to about 700-1000 km. This article addresses the impact of the atmospheric drag on mean semi-major axes and orbital eccentricities of geodetic spherical satellites: Starlette, Stella, AJISAI, and LARES. Atmospheric drag causes the semi-major axis decays amounting to about ▲a = -1.2, -.12, -.14, and -.30 m/year for LARES, AJISAI, Starlette, and Stella, respectively. The density of the upper atmosphere strongly depends on the solar and geomagnetic activity. The atmospheric drag affects the along-track orbit component to the largest extent, and the out-of-plane to a small extent, whereas the radial component is almost unaffected by the atmospheric drag.

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Propagation of satellite orbit modelling deficiencies into the global GNSS solutions – simulation-based study

10.5194/egusphere-egu21-6341 ◽

2021 ◽

Author(s):

Maciej Kalarus ◽

Rolf Dach ◽

Arturo Villiger ◽

Adrian Jaeggi

Keyword(s):

Satellite Orbit ◽

Force Model ◽

Satellite Orbits ◽

Model Errors ◽

Simulation Environment ◽

Satellite Clock ◽

Station Coordinates ◽

Earth Rotation Parameters ◽

Simulation Based ◽

The Impact

The Non-Gravitational Perturbations (NGP), out of which the Solar Radiation Pressure (SRP) is the largest, have a significant impact on GNSS satellite orbits. In addition to the SRP, other relevant perturbations should also be taken into account, as this may result in substantial modelling errors if underestimated. Particularly, the force model should also consider Earth&#8217;s albedo in terms of the emitted and reflected radiation, as well as a physical satellite model (box-wing) with its optical and thermal properties. GNSS satellite orbit modelling may suffer from deficiencies for various reasons (simplification of the complexity of the used model or uncertainty of the input information). The impact of such model errors on global GNSS data analyses is assessed in an error propagation study based on simulated observations. The influence of artificially introduced orbit errors on estimated parameters, e.g. Earth rotation parameters, orbit parameters (initial conditions and dynamical orbit parameters), station coordinates, station-wise troposphere parameters, as well as receiver and satellite clock corrections is investigated. In this study a dedicated simulation environment is used to analyse the relation between results and certain individual shortcomings in the NGP models. In addition, apart from a commonly used epoch-wise clock estimation, the analytical models for satellite clock corrections are introduced in order to exploit the high stability of the passive H-masers on-board the Galileo satellites. The simulation environment also allows to assess how the impact of float- versus fixed-ambiguities. Finally, simulation-based analyses offer an excellent framework for more detailed validations and further refinements of the physical satellite models, which will consequently stabilize the global solution.

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Influence of non-gravitational effects on the Centaur upper stage of the Surveyor 2 spacecraft

Journal of Physics Conference Series ◽

10.1088/1742-6596/2103/1/012029 ◽

2021 ◽

Vol 2103 (1) ◽

pp. 012029

Author(s):

A A Martyusheva ◽

A V Devyatkin

Keyword(s):

Solar Radiation Pressure ◽

Close Approach ◽

Major Axis ◽

Semi Major Axis ◽

Maximum Displacement ◽

Gravitational Effects ◽

Yarkovsky Effect ◽

Upper Stage ◽

The Impact ◽

Heliocentric Orbit

Abstract A small near-Earth asteroid, discovered by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) on September 17, 2020, turned out to be a part of the Centaur upper stage of the Surveyor 2 spacecraft launched by NASA on September 20, 1966 and subsequently crashed. This object had moved in a heliocentric orbit until it was under the influence of Earth’s gravitational field. As a result, a close approach to the Earth took place at a distance of about 50000 km on December 1, 2020. Despite the fact that the Centaur escaped back into a new orbit around the Sun in March 2021, it is of special interest for research, in particular, to consider the impact of non-gravitational effects on its orbital characteristics. Thus, it was calculated that the maximum displacement of the object trajectory due to the influence of solar radiation pressure over 15 years (the next close approach will take place in 2036) can be about 10.3-13.5 km, depending on the albedo. Estimations of the Yarkovsky effect showed that the magnitude of the expected change in the semi-major axis of Centaur’s orbit is from -8.1 • 10−13 to 1.6 10−13, depending on the angle of its rotation.

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Impact of low-degree gravity field estimation in the SLR data processing of spherical satellites at AIUB

10.5194/egusphere-egu21-4305 ◽

2021 ◽

Author(s):

Linda Geisser ◽

Ulrich Meyer ◽

Daniel Arnold ◽

Adrian Jäggi ◽

Daniela Thaller

Keyword(s):

Gravity Field ◽

Lower Altitude ◽

Earth’S Gravity Field ◽

Low Degree ◽

Station Coordinates ◽

Earth Rotation Parameters ◽

Field Estimation ◽

University Of Bern ◽

The University ◽

The Impact

The Astronomical Institute of the University of Bern (AIUB) collaborates with the Federal Agency for Cartography and Geodesy (BKG) in Germany to develop new procedures to generate products for the International Laser Ranging Service (ILRS). In this framework the SLR processing of the standard ILRS weekly solutions of spherical geodetic satellites at AIUB, where the orbits are determined in 7-day arcs together with station coordinates and other geodetic parameters, is extended from LAGEOS-1/2 and the Etalon-1/2 satellites to also include the LARES satellite orbiting the Earth at much lower altitude. Since a lower orbit experiences a more variable enviroment, e.g. it is more sensitive to time-variable Earth's gravity field, the orbit parametrization has to be adapted and also the low degree spherical harmonic coefficients of Earth's gravity field have to be co-estimated. The impact of the gravity field estimation is studied by validating the quality of other geodetic parameters such as geocenter coordinates, Earth Rotation Parameters (ERPs) and station coordinates. The analysis of the influence of LARES on the SLR solution shows that a good datum definition is important.

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Simulation studies on single-satellite space ties and their potential to achieve the Global Geodetic Observing System goals.

10.5194/egusphere-egu2020-7991 ◽

2020 ◽

Author(s):

Patrick Schreiner ◽

Nicat Mammadaliyev ◽

Susanne Glaser ◽

Rolf Koenig ◽

Karl Hans Neumayer ◽

...

Keyword(s):

Reference Frame ◽

Precise Orbit Determination ◽

Terrestrial Reference Frame ◽

German Research Foundation ◽

Station Coordinates ◽

Earth Rotation Parameters ◽

German Research ◽

Space Geodetic Techniques ◽

The Impact ◽

Space Ties

The German Research Foundation (DFG) project GGOS-SIM-2, successor of project GGOS-SIM, is a collaboration between the Helmholtz Center Potsdam - German Research Center for Geosciences (GFZ) and the Technische Universit&#228;t Berlin (TUB). The project aims at investigating the feasibility of meeting the requirements specified by the Global Geodetic Observing System (GGOS) for a global terrestrial reference frame (TRF) with the help of simulations. In GGOS-SIM-2 the potential of so-called space ties is examined in relation to the GGOS targets, 1 mm accuracy in position and 1 mm / decade long-term stability, which have not yet been achieved by the recent International Terrestrial Reference Frame (ITRF). Space ties are provided by a satellite that carries two, three or all the four main space-geodetic techniques, i.e. DORIS, GPS, SLR and VLBI. This allows for a quantification of the impact of systematic errors on the derived orbits and subsequent results of the dynamic method as the TRF. Proposed co-location in space missions such as GRASP and E-GRASP anticipate such a scenario. We therefor simulate the space-geodetic observations based on Precise Orbit Determination (POD) with real observations from various missions and evaluate their potential for determining a TRF. So far, we simulated DORIS and SLR observations to six orbit scenarios, including a GRASP-like and an E-GRASP-like one, and generated TRFs based on each scenario either technique-wise or combined via the space-ties or in combination with ground data. We quantify the effect on the TRF in terms of changes of origin and scale and of formal errors of the ground station coordinates and of the Earth rotation parameters.

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Increasing the Accuracy of Orbital Elements for a Satellite in a Low Earth Orbit under the Influence of Atmospheric Drag Using Adams-Bashforth Method

Iraqi Journal of Science ◽

10.24996/ijs.2021.si.2.9 ◽

2021 ◽

pp. 81-90

Author(s):

Rasha H. Ibrahim ◽

Abdul-Rahman H. Saleh

Keyword(s):

Integration Method ◽

Major Axis ◽

Low Earth Orbit ◽

True Anomaly ◽

Earth Orbit ◽

Atmospheric Drag ◽

Orbital Elements ◽

Semi Major Axis ◽

Literature Reviews ◽

Perturbed Equation

The perturbed equation of motion can be solved by using many numerical methods. Most of these solutions were inaccurate; the fourth order Adams-Bashforth method is a good numerical integration method, which was used in this research to study the variation of orbital elements under atmospheric drag influence. A satellite in a Low Earth Orbit (LEO), with altitude form perigee = 200 km, was selected during 1300 revolutions (84.23 days) and ASat / MSat value of 5.1 m2/ 900 kg. The equations of converting state vectors into orbital elements were applied. Also, various orbital elements were evaluated and analyzed. The results showed that, for the semi-major axis, eccentricity and inclination have a secular falling discrepancy, Longitude of Ascending Node is periodic, Argument of Perigee has a secular increasing variation, while true anomaly grows linearly from 0 to 360°. Furthermore, all orbital elements, excluding Longitude of Ascending Node, Argument of Perigee, and true anomaly, were more affected by drag than other orbital elements, through their falling as the time passes. The results illustrate a high correlation as compared with literature reviews in this field.

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Atmospheric drag effects on modelled LEO satellites during the July 2000 Bastille Day event in contrast to an interval of geomagnetically quiet conditions

10.5194/angeo-2020-33 ◽

2020 ◽

Author(s):

Victor U. J. Nwankwo ◽

William Denig ◽

Sandip K. Chakrabarti ◽

Muyiwa P. Ajakaiye ◽

Johnson Fatokun ◽

...

Keyword(s):

Geomagnetic Activity ◽

Low Earth Orbit ◽

Decay Rates ◽

Satellite Orbits ◽

Percentage Increase ◽

Atmospheric Drag ◽

Mean Values ◽

Satellite Drag ◽

Ballistic Coefficient ◽

The Impact

Abstract. In this work we simulated the effects of atmospheric drag on two model SmallSats in Low Earth Orbit (LEO) with different ballistic coefficients during 1-month intervals of solar-geomagnetic quiet and perturbed conditions. The goal of this effort was to quantify how solar-geomagnetic activity influences atmospheric drag and perturbs satellite orbits. Atmospheric drag compromises satellite operations due to increased ephemeris errors, attitude positional uncertainties and premature satellite re-entry. During a 1-month interval of generally quiescent solar-geomagnetic activity (July 2006) the decay in altitude (h) was a modest 0.53 km (0.66 km) for the satellite with the smaller (larger) ballistic coefficient of 2.2 × 10−3 m2/kg (3.03 × 10−3 m2/kg). The associated Orbital Decay Rates (ODRs) during this quiet interval ranged from 13 m/day to 23 m/day (from 16 m/day to 29 m/day). For the disturbed interval of July 2000 the significantly increased altitude loss and range of ODRs were 2.77 km (3.09 km) and 65 m/day to 120 m/day (78 m/day to 142 m/day), respectively. Within the two periods more detailed analyses over 12-day intervals of extremely quiet and disturbed conditions revealed respective orbital decays of 0.16 km (0.20 km) and 1.14 km (1.27 km) for the satellite with the smaller (larger) ballistic coefficient. In essence, the model results show that there was a 6–7 fold increase in the deleterious impacts of satellite drag between the quiet and disturbed periods. We also estimated the enhanced atmospheric drag effect on the satellites' parameters caused by the July 2000 Bastille Day event (in contrast to the interval of geomagnetically quiet conditions). The additional percentage increase due to the Bastille Day event to the monthly mean values of h and ODR are 34.69 % and 50.13 % for Sat-A, and 36.45 % and 68.95 % for Sat-B. These simulations confirmed; (i) the dependence of atmospheric drag force on a satellite's ballistic coefficient, and (ii) that increased solar-geomagnetic activity substantially raises the degrading effect of satellite drag. In addition, the results indicate that the impact of short-duration geomagnetic transients can have a further deleterious effect on normal satellite operations. While none of these findings were particularly surprising or profound we suggest that a model of satellite drag when combined with a high-fidelity atmospheric specification, as was done here, can lead to improved satellite ephemeris estimates.

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Ring dynamics around an oblate body with an inclined satellite: the case of Haumea

Astronomy and Astrophysics ◽

10.1051/0004-6361/202038812 ◽

2020 ◽

Vol 643 ◽

pp. A67

Author(s):

Francesco Marzari

Keyword(s):

Equatorial Plane ◽

Protective Factor ◽

Central Body ◽

Orbital Plane ◽

Major Axis ◽

The Body ◽

Triaxial Ellipsoid ◽

Semi Major Axis ◽

Short Timescale ◽

The Impact

Context. The recent discovery of rings and massive satellites around minor bodies and dwarf planets suggests that they may often coexist, as for example around Haumea. Aims. A ring perturbed by an oblate central body and by an inclined satellite may disperse on a short timescale. The conditions under which a ring may survive are explored both analytically and numerically. Methods. The trajectories of ring particles are integrated under the influence of the gravitational field of a triaxial ellipsoid and (a) massive satellite(s), including the effects of collisions. Results. A ring initially formed in the equatorial plane of the central body will be disrupted if the satellite has an inclination in the Kozai–Lidov regime (39.2° < i < 144.8). For lower inclinations, the ring may relax to the satellite orbital plane thanks to an intense collisional damping. On the other hand, a significant J2 term easily suppresses the perturbations of an inclined satellite within a critical semi-major axis, even in the case of Kozai–Lidov cycles. However, if the ring is initially inclined with respect to the equatorial plane, the same J2 perturbations are not a protective factor but instead disrupt the ring on a short timescale. The ring found around Haumea is stable despite the rise in the impact velocities that is due to the asymmetric shape of the body and the presence of a 3:1 resonance with the rotation of the central body. Conclusions. A ring close to an oblate central body should be searched for in the proximity of the equatorial plane, where the J2 perturbations protect it against the perturbations of an external inclined satellites. In an inclined configuration, the J2 term is itself disruptive.

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Atmospheric drag effects on modelled low Earth orbit (LEO) satellites during the July 2000 Bastille Day event in contrast to an interval of geomagnetically quiet conditions

Annales Geophysicae ◽

10.5194/angeo-39-397-2021 ◽

2021 ◽

Vol 39 (3) ◽

pp. 397-412

Author(s):

Victor U. J. Nwankwo ◽

William Denig ◽

Sandip K. Chakrabarti ◽

Muyiwa P. Ajakaiye ◽

Johnson Fatokun ◽

...

Keyword(s):

Geomagnetic Activity ◽

Low Earth Orbit ◽

Earth Orbit ◽

Satellite Orbits ◽

Percentage Increase ◽

Atmospheric Drag ◽

Drag Effect ◽

Satellite Drag ◽

Ballistic Coefficient ◽

The Impact

Abstract. In this work, we simulated the atmospheric drag effect on two model SmallSats (small satellites) in low Earth orbit (LEO) with different ballistic coefficients during 1-month intervals of solar–geomagnetic quiet and perturbed conditions. The goal of this effort was to quantify how solar–geomagnetic activity influences atmospheric drag and perturbs satellite orbits, with particular emphasis on the Bastille Day event. Atmospheric drag compromises satellite operations due to increased ephemeris errors, attitude positional uncertainties and premature satellite re-entry. During a 1-month interval of generally quiescent solar–geomagnetic activity (July 2006), the decay in altitude (h) was a modest 0.53 km (0.66 km) for the satellite with the smaller (larger) ballistic coefficient of 2.2×10-3 m2 kg−1 (3.03×10-3 m2 kg−1). The associated orbital decay rates (ODRs) during this quiet interval ranged from 13 to 23 m per day (from 16 to 29 m per day). For the disturbed interval of July 2000 the significantly increased altitude loss and range of ODRs were 2.77 km (3.09 km) and 65 to 120 m per day (78 to 142 m per day), respectively. Within the two periods, more detailed analyses over 12 d intervals of extremely quiet and disturbed conditions revealed respective orbital decays of 0.16 km (0.20 km) and 1.14 km (1.27 km) for the satellite with the smaller (larger) ballistic coefficient. In essence, the model results show that there was a 6- to 7-fold increase in the deleterious impacts of satellite drag between the quiet and disturbed periods. We also estimated the enhanced atmospheric drag effect on the satellites' parameters caused by the July 2000 Bastille Day event (in contrast to the interval of geomagnetically quiet conditions). The additional percentage increase, due to the Bastille Day event, to the monthly mean values of h and ODR are 34.69 % and 50.13 % for Sat-A and 36.45 % and 68.95 % for Sat-B. These simulations confirmed (i) the dependence of atmospheric drag force on a satellite's ballistic coefficient, and (ii) that increased solar–geomagnetic activity substantially raises the degrading effect of satellite drag. In addition, the results indicate that the impact of short-duration geomagnetic transients (such as the Bastille Day storm) can have a further deleterious effect on normal satellite operations. Thus, this work increases the visibility and contributes to the scientific knowledge surrounding the Bastille Day event and also motivates the introduction of new indices used to describe and estimate the atmospheric drag effect when comparing regimes of varying solar–geomagnetic activity. We suggest that a model of satellite drag, when combined with a high-fidelity atmospheric specification as was done here, can lead to improved satellite ephemeris estimates.

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ORBITAL EFFECTS OF A TIME-DEPENDENT PIONEER-LIKE ANOMALOUS ACCELERATION

Modern Physics Letters A ◽

10.1142/s021773231250071x ◽

2012 ◽

Vol 27 (12) ◽

pp. 1250071 ◽

Cited By ~ 8

Author(s):

L. IORIO

Keyword(s):

Major Axis ◽

Time Dependent ◽

Semi Major Axis ◽

Orbital Parameters ◽

Estimated Parameters ◽

Secular Variations ◽

Dependent Component ◽

Orbital Revolution ◽

Anomalous Acceleration ◽

The Impact

We work out the impact that the recently determined time-dependent component of the Pioneer Anomaly (PA), if interpreted as an additional exotic acceleration of gravitational origin with respect to the well-known PA-like constant one, may have on the orbital motions of some planets of the solar system. By assuming that it points towards the Sun, it turns out that both the semi-major axis a and the eccentricity e of the orbit of a test particle would experience secular variations. For Saturn and Uranus, for which modern data records cover at least one full orbital revolution, such predicted anomalies are up to 2–3 orders of magnitude larger than the present-day accuracies in empirical determinations of their orbital parameters from the usual orbit determination procedures in which the PA was not modeled. Given the predicted huge sizes of such hypothetical signatures, it is unlikely that their absence from the presently available processed data can be attributable to an "absorption" for them in the estimated parameters caused by the fact that they were not explicitly modeled. The magnitude of a constant PA-type acceleration at 9.5 au cannot be larger than 9×10-15 m s-2 according to the latest observational results for the perihelion precession of Saturn.

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A discussion on orbital analysis - Odd zonal harmonics in the geopotential, determined from fourteen well-distributed satellite orbits

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1967.0041 ◽

1967 ◽

Vol 262 (1124) ◽

pp. 144-147

Keyword(s):

Gravitational Potential ◽

Major Axis ◽

Detailed Account ◽

Satellite Orbits ◽

Orbital Eccentricity ◽

Semi Major Axis ◽

Orbital Inclination ◽

Zonal Harmonics ◽

Distributed Satellite ◽

Orbital Analysis

Coefficients of the odd zonal harmonics in the Earth’s gravitational potential are evaluated by analysing the oscillations in orbital eccentricity of fourteen satellites chosen to give the widest and most uniform possible distribution in orbital inclination and semi-major axis. The best representations of the odd zonal harmonics are found to be in terms of seven coefficients (J5, */15)) or ten coefficients (J 3,J 5, J 21) and values for these coefficients are given. A detailed account of this work is being published in Planetary and Space Science.

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