scholarly journals Cubesat attitude determination

2021 ◽  
Author(s):  
Anastasia Bondarenko
Keyword(s):  
Magnetic Fields ◽  
Surface Area ◽  
Attitude Determination ◽  
Solar Array ◽  
The Sun ◽  
Earth Surface ◽  
Atmospheric Drag ◽  
Solar Winds ◽  
The Earth ◽  
Specific Orientation

When satellites are placed in orbit, often times a specific orientation is required to achieve mission purposes. Different factors (such as atmospheric drag, magnetic fields, solar winds) or tumbling upon deployment from the launch vehicle, may result in an undesirable satellite orientation. To address these challenges, the ability to control the orientation, termed as attitude determination, becomes critical to any mission. This thesis will focus on developing an earth-pointing and sun-pointing mode in order to meet the objectives of the ESSENCE CubeSat. The earth-pointing mode orients the vehicle to point towards a desired target on the earth surface, and the sun-pointing mode orients the vehicle such that the maximum solar array surface area is exposed to the sun when the vehicle is out of eclipse.

scholarly journals Cubesat attitude determination

2021 ◽  
Author(s):  
Anastasia Bondarenko
Keyword(s):  
Magnetic Fields ◽  
Surface Area ◽  
Attitude Determination ◽  
Solar Array ◽  
The Sun ◽  
Earth Surface ◽  
Atmospheric Drag ◽  
Solar Winds ◽  
The Earth ◽  
Specific Orientation

When satellites are placed in orbit, often times a specific orientation is required to achieve mission purposes. Different factors (such as atmospheric drag, magnetic fields, solar winds) or tumbling upon deployment from the launch vehicle, may result in an undesirable satellite orientation. To address these challenges, the ability to control the orientation, termed as attitude determination, becomes critical to any mission. This thesis will focus on developing an earth-pointing and sun-pointing mode in order to meet the objectives of the ESSENCE CubeSat. The earth-pointing mode orients the vehicle to point towards a desired target on the earth surface, and the sun-pointing mode orients the vehicle such that the maximum solar array surface area is exposed to the sun when the vehicle is out of eclipse.

3D MHD study of the Earth magnetosphere response during extreme space weather conditions

2021 ◽  
Author(s):  
Jacobo Varela Rodriguez ◽  
Sacha A. Brun ◽  
Antoine Strugarek ◽  
Victor Réville ◽  
Filippo Pantellini ◽  
...  
Keyword(s):  
Solar Wind ◽  
Space Weather ◽  
Coronal Mass Ejections ◽  
Main Sequence ◽  
Dynamic Pressure ◽  
Weather Conditions ◽  
The Sun ◽  
Earth Surface ◽  
The Earth ◽  
The Imf

<p><span>The aim of the study is to analyze the response of the Earth magnetosphere for various space weather conditions and model the effect of interplanetary coronal mass ejections. The magnetopause stand off distance, open-closed field lines boundary and plasma flows towards the planet surface are investigated. We use the MHD code PLUTO in spherical coordinates to perform a parametric study regarding the dynamic pressure and temperature of the solar wind as well as the interplanetary magnetic field intensity and orientation. The range of the parameters analyzed extends from regular to extreme space weather conditions consistent with coronal mass ejections at the Earth orbit. The direct precipitation of the solar wind on the Earth day side at equatorial latitudes is extremely unlikely even during super coronal mass ejections. For example, the SW precipitation towards the Earth surface for a IMF purely oriented in the Southward direction requires a IMF intensity around 1000 nT and the SW dynamic pressure above 350 nPa, space weather conditions well above super-ICMEs. The analysis is extended to previous stages of the solar evolution considering the rotation tracks from Carolan (2019). The simulations performed indicate an efficient shielding of the Earth surface 1100 Myr after the Sun enters in the main sequence. On the other hand, for early evolution phases along the Sun main sequence once the Sun rotation rate was at least 5 times faster (< 440 Myr), the Earth surface was directly exposed to the solar wind during coronal mass ejections (assuming today´s Earth magnetic field). Regarding the satellites orbiting the Earth, Southward and Ecliptic IMF orientations are particularly adverse for Geosynchronous satellites, partially exposed to the SW if the SW dynamic pressure is 8-14 nPa and the IMF intensity 10 nT. On the other hand, Medium orbit satellites at 20000 km are directly exposed to the SW during Common ICME if the IMF orientation is Southward and during Strong ICME if the IMF orientation is Earth-Sun or Ecliptic. The same way, Medium orbit satellites at 10000 km are directly exposed to the SW if a Super ICME with Southward IMF orientation impacts the Earth.</span></p><p>This work was supported by the project 2019-T1/AMB-13648 founded by the Comunidad de Madrid, grants ERC WholeSun, Exoplanets A and PNP. We extend our thanks to CNES for Solar Orbiter, PLATO and Meteo Space science support and to INSU/PNST for their financial support.</p>

Variations of the magnetic fields of the sun and the earth in 7?50 day periods

Solar Physics ◽  
1994 ◽  
Vol 152 (1) ◽  
pp. 291-296 ◽  
Author(s):  
V. P. Bobova ◽  
N. N. Stepanian
Keyword(s):  
Magnetic Fields ◽  
The Sun ◽  
The Earth

Periodic imbalances of kinetic and magnetic energies in rotating magnetohydrodynamic turbulent flows

2020 ◽  
Author(s):  
Rustem Sirazov ◽  
Arakel Petrosyan
Keyword(s):  
Magnetic Fields ◽  
Temporal Dynamics ◽  
Wave Packets ◽  
Homogeneous Turbulence ◽  
Initial Time ◽  
The Sun ◽  
Magnetohydrodynamic Turbulence ◽  
The Earth ◽  
Magnetohydrodynamic Flows ◽  
N Wave

<p>A significant number of observed flows in geophysics, astrophysics, and laboratory experiments are in a state of magnetohydrodynamic turbulence. Among them are flows in the Earth’s outer core, in plasma shells of Earth, planets, and satellites of the solar system with strong magnetic fields, as well as flows in the Sun, stars, and astrophysical disks. Despite significant advances in the study of turbulence under the conditions typical of thermonuclear fusion devices, studies of the fundamental properties of homogeneous turbulence in rotating magnetohydrodynamic flows are still fragmentary and mainly concern turbulence in astrophysical disks, the solar tachocline and convective region of the Sun, and two-dimensional magnetohydrodynamic flows on the β-plane. Only in a few exceptional works were the properties of magnetohydrodynamic turbulence studied by simple analytical methods using Fourier series for similarity parameters, characteristic of the Earth’s core.</p><p>The aim of this work is to study the influence of the interaction of Alfvén wave packets on the dynamics of homogeneous turbulence. The method of calculation o magnetohydrodynamic turbulence we developed allows numerical simulation at large characteristic times and large external magnetic fields. The proposed method of setting the initial conditions for the velocity field makes it possible to satisfy the divergence-free, homogeneity, and turbulence isotropy conditions, as well as to set an arbitrary spectral distribution of the energy at the initial time without additional calculations. Numerical experiments demonstrate a nontrivial behavior of turbulent kinetic and magnetic energies. It is shown that periodic imbalance in energies occurs in the system in the form of conversion of kinetic energy into magnetic energy and vice versa. The analysis of the results shows that the detected nontrivial temporal dynamics of turbulence is caused by the periodic collisions of Alfvén wave packets.</p><p>This work was supported by the Russian Foundation for Basic Research (project no. 19-02-00016).</p>

scholarly journals Is There an Oblique Magnetic Rotator Inside the Sun?

1983 ◽  
Vol 66 ◽  
pp. 235-235
Author(s):  
G.R. Isaak
Keyword(s):  
Magnetic Fields ◽  
Convection Zone ◽  
Detailed Account ◽  
The Sun ◽  
Magnetic Perturbation ◽  
The Earth ◽  
Solar Oblateness

AbstractThe size of the rotational splitting recently observed (Claverie et al., 1981) is correlated with the 12.2d variation in the measurements of solar oblateness observed by Dicke (1976) and implies a convection zone of depth of 0.1 Rʘ. The near equality of amplitudes of global velocity oscillations (Claverie et al, 1981) of the various m components of the l = 1 and l = 2 modes as seen from the Earth viewing the Sun nearly along the equator is unexpected for pure rotational splitting. It is suggested that a magnetic perturbation is present and an oblique asymmetric magnetic rotator with magnetic fields of a few million gauss is responsible. A more detailed account was submitted to Nature.

The magnetic Sun

2008 ◽  
Vol 366 (1871) ◽  
pp. 1735-1748 ◽  
Author(s):  
Richard A Harrison
Keyword(s):  
Magnetic Fields ◽  
Stellar Atmospheres ◽  
Magnetic Star ◽  
The Sun ◽  
Basic Principles ◽  
Fundamental Nature ◽  
James Clerk Maxwell ◽  
The Earth ◽  
Basic Equations ◽  
The Way

The nature of our star, the Sun, is dominated by its complex and variable magnetic fields. It is the purpose of this paper to review the fundamental nature of our magnetic Sun by outlining the most basic principles behind the way the Sun works and how its fields are generated, and to examine not only the historical observations of our magnetic star, but, in particular, to study the wonderful observations of the Sun being made from space today. However, lying behind all of this are the most basic equations derived by James Clerk Maxwell, describing how the magnetic fields and plasmas of our Sun's atmosphere, and indeed of all stellar atmospheres, work and how they influence the Earth.

The interconnection of the magnetic fields of the Earth and the Sun

Endeavour ◽  
1991 ◽  
Vol 15 (3) ◽  
pp. 126-132
Author(s):  
Michael Lockwood
Keyword(s):  
Magnetic Fields ◽  
The Sun ◽  
The Earth

Geophysics: A Very Short Introduction

2018 ◽  
Author(s):  
William Lowrie
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Plate Tectonics ◽  
Seismic Waves ◽  
Outer Space ◽  
The Sun ◽  
Short Introduction ◽  
The Earth ◽  
Gravity And Magnetic ◽  
Harmful Radiation

Geophysics is the physics of the Earth. It encompasses areas such as seismology, plate tectonics, gravity, and the Earth’s magnetic field, all of which give clues to both the structure and the working of the Earth. Geophysics: A Very Short Introduction describes the internal and external processes that affect the planet, as well as the techniques used by geophysicists to investigate them. It explains how analysis of the seismic waves produced in earthquakes reveals the Earth’s internal structure, and tells how heat is transported through its interior. Chapters describe how satellite missions measure the gravity and magnetic fields, and explain how its magnetic field shields the Earth against harmful radiation from the Sun and outer space.

scholarly journals Possible Advantages of a Twin Spacecraft Heliospheric Mission at the Sun-Earth Lagrangian Points L4 and L5

2021 ◽  
Vol 8 ◽  
Author(s):  
A. Bemporad
Keyword(s):  
Remote Sensing ◽  
Magnetic Fields ◽  
Vantage Point ◽  
The Sun ◽  
Missing Information ◽  
Lagrangian Points ◽  
The Earth ◽  
Coronal Magnetic Fields ◽  
Solar Disturbances

After the launch of STEREO twin spacecraft, and most recently of Solar Orbiter and Parker Solar Probe spacecraft, the next mission that will explore Sun-Earth interactions and how the Sun modulates the Heliosphere will be the “Lagrange” mission, which will consist of two satellites placed in orbit around L1 and L5 Sun-Earth Lagrangian points. Despite the significant novelties that will be provided by such a double vantage point, there will be also missing information, that are briefly discussed here. For future heliospheric missions, an alternative advantageous approach that has not been considered so far would be to place two twin spacecraft not in L1 and L5, but in L4 and L5 Lagrangian points. If these two spacecraft will be equipped with in situ instruments, and also remote sensing instruments measuring not only photospheric but also coronal magnetic fields, significant advancing will be possible. In particular, data provided by such a twin mission will allow to follow the evolution of magnetic fields from inside the Sun (with stereoscopic helioseismology), to its surface (with classical photospheric magnetometers), and its atmosphere (with spectro-polarimeters); this will provide a tremendous improvement in our physical understanding of solar activity. Moreover, the L4-L5 twin satellites will take different interesting configurations, such as relative quadrature, and quasi-quadrature with the Earth, providing a baseline for monitoring the Sun-to-Earth propagation of solar disturbances.

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