Law of Universal Magnetism, F = Ke × H
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Stability of the Moons Orbits in Solar System in the Restricted Three-Body
Stability of the Moons orbits in Solar system in the restricted three-body problem Sergey V. Ershkov, Institute for Time Nature Explorations, M.V. Lomonosov's Moscow State University, Leninskie gory, 1-12, Moscow 119991, Russia e-mail: [email protected] Abstract: We consider the equations of motion of three-body problem in a Lagrange form (which means a consideration of relative motions of 3-bodies in regard to each other). Analyzing such a system of equations, we consider in details the case of moon‟s motion of negligible mass m₃ around the 2-nd of two giant-bodies m₁, m₂ (which are rotating around their common centre of masses on Kepler’s trajectories), the mass of which is assumed to be less than the mass of central body. Under assumptions of R3BP, we obtain the equations of motion which describe the relative mutual motion of the centre of mass of 2-nd giant-body m₂ (Planet) and the centre of mass of 3-rd body (Moon) with additional effective mass m₂ placed in that centre of mass (m₂ + m₃), where is the dimensionless dynamical parameter. They should be rotating around their common centre of masses on Kepler‟s elliptic orbits. For negligible effective mass (m₂ + m₃) it gives the equations of motion which should describe a quasi-elliptic orbit of 3-rd body (Moon) around the 2-nd body m₂ (Planet) for most of the moons of the Planets in Solar system. But the orbit of Earth‟s Moon should be considered as non-constant elliptic motion for the effective mass 0.0178m₂ placed in the centre of mass for the 3-rd body (Moon). -
Reduction of Saturn Orbit Insertion Impulse Using Deep-Space Low Thrust
Reduction of Saturn Orbit Insertion Impulse using Deep-Space Low Thrust Elena Fantino ∗† Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates. Roberto Flores‡ International Center for Numerical Methods in Engineering, 08034 Barcelona, Spain. Jesús Peláez§ and Virginia Raposo-Pulido¶ Technical University of Madrid, 28040 Madrid, Spain. Orbit insertion at Saturn requires a large impulsive manoeuver due to the velocity difference between the spacecraft and the planet. This paper presents a strategy to reduce dramatically the hyperbolic excess speed at Saturn by means of deep-space electric propulsion. The inter- planetary trajectory includes a gravity assist at Jupiter, combined with low-thrust maneuvers. The thrust arc from Earth to Jupiter lowers the launch energy requirement, while an ad hoc steering law applied after the Jupiter flyby reduces the hyperbolic excess speed upon arrival at Saturn. This lowers the orbit insertion impulse to the point where capture is possible even with a gravity assist with Titan. The control-law algorithm, the benefits to the mass budget and the main technological aspects are presented and discussed. The simple steering law is compared with a trajectory optimizer to evaluate the quality of the results and possibilities for improvement. I. Introduction he giant planets have a special place in our quest for learning about the origins of our planetary system and Tour search for life, and robotic missions are essential tools for this scientific goal. Missions to the outer planets arXiv:2001.04357v1 [astro-ph.EP] 8 Jan 2020 have been prioritized by NASA and ESA, and this has resulted in important space projects for the exploration of the Jupiter system (NASA’s Europa Clipper [1] and ESA’s Jupiter Icy Moons Explorer [2]), and studies are underway to launch a follow-up of Cassini/Huygens called Titan Saturn System Mission (TSSM) [3], a joint ESA-NASA project. -
Electric Propulsion System Scaling for Asteroid Capture-And-Return Missions
Electric propulsion system scaling for asteroid capture-and-return missions Justin M. Little⇤ and Edgar Y. Choueiri† Electric Propulsion and Plasma Dynamics Laboratory, Princeton University, Princeton, NJ, 08544 The requirements for an electric propulsion system needed to maximize the return mass of asteroid capture-and-return (ACR) missions are investigated in detail. An analytical model is presented for the mission time and mass balance of an ACR mission based on the propellant requirements of each mission phase. Edelbaum’s approximation is used for the Earth-escape phase. The asteroid rendezvous and return phases of the mission are modeled as a low-thrust optimal control problem with a lunar assist. The numerical solution to this problem is used to derive scaling laws for the propellant requirements based on the maneuver time, asteroid orbit, and propulsion system parameters. Constraining the rendezvous and return phases by the synodic period of the target asteroid, a semi- empirical equation is obtained for the optimum specific impulse and power supply. It was found analytically that the optimum power supply is one such that the mass of the propulsion system and power supply are approximately equal to the total mass of propellant used during the entire mission. Finally, it is shown that ACR missions, in general, are optimized using propulsion systems capable of processing 100 kW – 1 MW of power with specific impulses in the range 5,000 – 10,000 s, and have the potential to return asteroids on the order of 103 104 tons. − Nomenclature -
Stellar Dynamics and Stellar Phenomena Near a Massive Black Hole
Stellar Dynamics and Stellar Phenomena Near A Massive Black Hole Tal Alexander Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 234 Herzl St, Rehovot, Israel 76100; email: [email protected] | Author's original version. To appear in Annual Review of Astronomy and Astrophysics. See final published version in ARA&A website: www.annualreviews.org/doi/10.1146/annurev-astro-091916-055306 Annu. Rev. Astron. Astrophys. 2017. Keywords 55:1{41 massive black holes, stellar kinematics, stellar dynamics, Galactic This article's doi: Center 10.1146/((please add article doi)) Copyright c 2017 by Annual Reviews. Abstract All rights reserved Most galactic nuclei harbor a massive black hole (MBH), whose birth and evolution are closely linked to those of its host galaxy. The unique conditions near the MBH: high velocity and density in the steep po- tential of a massive singular relativistic object, lead to unusual modes of stellar birth, evolution, dynamics and death. A complex network of dynamical mechanisms, operating on multiple timescales, deflect stars arXiv:1701.04762v1 [astro-ph.GA] 17 Jan 2017 to orbits that intercept the MBH. Such close encounters lead to ener- getic interactions with observable signatures and consequences for the evolution of the MBH and its stellar environment. Galactic nuclei are astrophysical laboratories that test and challenge our understanding of MBH formation, strong gravity, stellar dynamics, and stellar physics. I review from a theoretical perspective the wide range of stellar phe- nomena that occur near MBHs, focusing on the role of stellar dynamics near an isolated MBH in a relaxed stellar cusp. -
Determination of Optimal Earth-Mars Trajectories to Target the Moons Of
The Pennsylvania State University The Graduate School Department of Aerospace Engineering DETERMINATION OF OPTIMAL EARTH-MARS TRAJECTORIES TO TARGET THE MOONS OF MARS A Thesis in Aerospace Engineering by Davide Conte 2014 Davide Conte Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science May 2014 ii The thesis of Davide Conte was reviewed and approved* by the following: David B. Spencer Professor of Aerospace Engineering Thesis Advisor Robert G. Melton Professor of Aerospace Engineering Director of Undergraduate Studies George A. Lesieutre Professor of Aerospace Engineering Head of the Department of Aerospace Engineering *Signatures are on file in the Graduate School iii ABSTRACT The focus of this thesis is to analyze interplanetary transfer maneuvers from Earth to Mars in order to target the Martian moons, Phobos and Deimos. Such analysis is done by solving Lambert’s Problem and investigating the necessary targeting upon Mars arrival. Additionally, the orbital parameters of the arrival trajectory as well as the relative required ΔVs and times of flights were determined in order to define the optimal departure and arrival windows for a given range of date. The first step in solving Lambert’s Problem consists in finding the positions and velocities of the departure (Earth) and arrival (Mars) planets for a given range of dates. Then, by solving Lambert’s problem for various combinations of departure and arrival dates, porkchop plots can be created and examined. Some of the key parameters that are plotted on porkchop plots and used to investigate possible transfer orbits are the departure characteristic energy, C3, and the arrival v∞. -
Astrodynamics (AERO0024)
Astrodynamics (AERO0024) The twobody problem Lamberto Dell'Elce Space Structures & Systems Lab (S3L)0 Outline The twobody problem µ rÜ = – r Equations of motion r 3 Resulting orbits 1 Outline The twobody problem µ rÜ = – r Equations of motion r 3 Resulting orbits 2 What is the twobody problem (or Kepler problem)? F 21 F m1 12 m2 Motion of two point masses due to their gravitational interaction 3 Twobody problem vs real world 4 What is the interest in the twobody problem? 5 Gravitational force of a point mass F 21 F m1 12 m2 r Norm: m1 m2 kF 12k = kF 21k = G r 2 Direction: • Along the line joining m1 and m2 • Directed toward the attractor 6 Gravitational constant 7 Gravitational parameter of a Celestial body 8 Satellite laser ranging 9 Satellites as bodies in free fall 10 Is pointmass a good approximation for Earth gravity? 11 Gravitational potential of a uniform sphere 12 Gravitational potential of a sphericallysymmetric body 13 Outline The twobody problem µ rÜ = – r Equations of motion r 3 Resulting orbits 14 Dynamics of the two bodies 15 Motion of the center of mass 16 Equations of relative motion Assume m2 m1 17 Equations of relative motion 18 Integrals of motion: The angular momentum 19 Implication: Motion lies in a plane 20 Azimuth component of the velocity 21 Integrals of motion: The eccentricity vector 22 Relative trajectory 23 In summary 24 Outline The twobody problem µ rÜ = – r Equations of motion r 3 Resulting orbits 25 Conic sections in polar coordinates 26 Conic sections 27 Possible trajectories of the twobody -
The Pennsylvania State University Schreyer Honors College
THE PENNSYLVANIA STATE UNIVERSITY SCHREYER HONORS COLLEGE DEPARTMENT OF AEROSPACE ENGINEERING LONG TERM ORBITAL MODELING FOR OBJECTS IN GEOSTATIONARY EARTH ORBIT PHILIP CHOW SPRING 2015 A thesis submitted in partial fulfillment of the requirements for a baccalaureate degree in Aerospace Engineering with honors in Aerospace Engineering Reviewed and approved* by the following: David B. Spencer Professor of Aerospace Engineering Thesis Supervisor Robert G. Melton Professor of Aerospace Engineering Honors Adviser George A. Lesieutre Professor of Aerospace Engineering Head of Aerospace Engineering * Signatures are on file in the Schreyer Honors College. i ABSTRACT The suitability of different numerical integrators for the long term orbital modeling of a satellite in geostationary Earth orbit is examined. The integrators used are the ODE45 Runge- Kutta Method from MATLAB and the symplectic Euler method, assuming only spherical harmonics of the Earth and n-body perturbations from the Sun, Moon, and other planets. Results show that the energy drift associated with both integrators makes them unsuitable for long term modeling, and that the symplectic Euler method does not actually maintain constant energy. A possible factor in the energy drift of both integrators includes the model used for n-body perturbations; future work should focus on determining the extent that this affected the results and the steps necessary to correct the errors. ii TABLE OF CONTENTS LIST OF FIGURES .................................................................................................... -
Orbital Mechanics
Danish Space Research Institute Danish Small Satellite Programme DTU Satellite Systems and Design Course Orbital Mechanics Flemming Hansen MScEE, PhD Technology Manager Danish Small Satellite Programme Danish Space Research Institute Phone: 3532 5721 E-mail: [email protected] Slide # 1 FH 2001-09-16 Orbital_Mechanics.ppt Danish Space Research Institute Danish Small Satellite Programme Planetary and Satellite Orbits Johannes Kepler (1571 - 1630) 1st Law • Discovered by the precision mesurements of Tycho Brahe that the Moon and the Periapsis - Apoapsis - planets moves around in elliptical orbits Perihelion Aphelion • Harmonia Mundi 1609, Kepler’s 1st og 2nd law of planetary motion: st • 1 Law: The orbit of a planet ia an ellipse nd with the sun in one focal point. 2 Law • 2nd Law: A line connecting the sun and a planet sweeps equal areas in equal time intervals. 3rd Law • 1619 came Keplers 3rd law: • 3rd Law: The square of the planet’s orbit period is proportional to the mean distance to the sun to the third power. Slide # 2 FH 2001-09-16 Orbital_Mechanics.ppt Danish Space Research Institute Danish Small Satellite Programme Newton’s Laws Isaac Newton (1642 - 1727) • Philosophiae Naturalis Principia Mathematica 1687 • 1st Law: The law of inertia • 2nd Law: Force = mass x acceleration • 3rd Law: Action og reaction • The law of gravity: = GMm F Gravitational force between two bodies F 2 G The universal gravitational constant: G = 6.670 • 10-11 Nm2kg-2 r M Mass af one body, e.g. the Earth or the Sun m Mass af the other body, e.g. the satellite r Separation between the bodies G is difficult to determine precisely enough for precision orbit calculations. -
Interacting Binaries with Eccentric Orbits. Secular Orbital Evolution
j-sepinsky, b-willems, [email protected], and [email protected] A Preprint typeset using LTEX style emulateapj v. 08/22/09 INTERACTING BINARIES WITH ECCENTRIC ORBITS. SECULAR ORBITAL EVOLUTION DUE TO CONSERVATIVE MASS TRANSFER J. F. Sepinsky, B. Willems, V. Kalogera, F. A. Rasio Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 j-sepinsky, b-willems, [email protected], and [email protected] ABSTRACT We investigate the secular evolution of the orbital semi-major axis and eccentricity due to mass transfer in eccentric binaries, assuming conservation of total system mass and orbital angular momen- tum. Assuming a delta function mass transfer rate centered at periastron, we find rates of secular change of the orbital semi-major axis and eccentricity which are linearly proportional to the magni- tude of the mass transfer rate at periastron. The rates can be positive as well as negative, so that the semi-major axis and eccentricity can increase as well as decrease in time. Adopting a delta-function −9 −1 mass-transfer rate of 10 M⊙ yr at periastron yields orbital evolution timescales ranging from a few Myr to a Hubble time or more, depending on the binary mass ratio and orbital eccentricity. Com- parison with orbital evolution timescales due to dissipative tides furthermore shows that tides cannot, in all cases, circularize the orbit rapidly enough to justify the often adopted assumption of instanta- neous circularization at the onset of mass transfer. The formalism presented can be incorporated in binary evolution and population synthesis codes to create a self-consistent treatment of mass transfer in eccentric binaries. -
Comparison of the Characteristic Energy of Precipitating Electrons Derived from Ground-Based and DMSP Satellite Data M
Comparison of the characteristic energy of precipitating electrons derived from ground-based and DMSP satellite data M. Ashrafi, M. J. Kosch, F. Honary To cite this version: M. Ashrafi, M. J. Kosch, F. Honary. Comparison of the characteristic energy of precipitating electrons derived from ground-based and DMSP satellite data. Annales Geophysicae, European Geosciences Union, 2005, 23 (1), pp.135-145. hal-00317498 HAL Id: hal-00317498 https://hal.archives-ouvertes.fr/hal-00317498 Submitted on 31 Jan 2005 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Annales Geophysicae (2005) 23: 135–145 SRef-ID: 1432-0576/ag/2005-23-135 Annales © European Geosciences Union 2005 Geophysicae Comparison of the characteristic energy of precipitating electrons derived from ground-based and DMSP satellite data M. Ashrafi, M. J. Kosch, and F. Honary Department of Communications Systems, Lancaster University, Lancaster, LA1 4WA, UK Received: 15 December 2003 – Revised: 16 April 2004 – Accepted: 5 May 2004 – Published: 31 January 2005 Part of Special Issue “Eleventh International EISCAT Workshop” Abstract. Energy maps are important for ionosphere- (Heppner et al., 1952; Campbell and Leinbach, 1961). Holt magnetosphere coupling studies, because quantitative de- and Omholt (1962) and Gustafsson (1969) found a good cor- termination of field-aligned currents requires knowledge of relation between the absorption and the intensity fluctuation the conductances and their spatial gradients. -
The Collisional Penrose Process
Noname manuscript No. (will be inserted by the editor) The Collisional Penrose Process Jeremy D. Schnittman Received: date / Accepted: date Abstract Shortly after the discovery of the Kerr metric in 1963, it was realized that a region existed outside of the black hole's event horizon where no time-like observer could remain stationary. In 1969, Roger Penrose showed that particles within this ergosphere region could possess negative energy, as measured by an observer at infinity. When captured by the horizon, these negative energy parti- cles essentially extract mass and angular momentum from the black hole. While the decay of a single particle within the ergosphere is not a particularly efficient means of energy extraction, the collision of multiple particles can reach arbitrar- ily high center-of-mass energy in the limit of extremal black hole spin. The re- sulting particles can escape with high efficiency, potentially erving as a probe of high-energy particle physics as well as general relativity. In this paper, we briefly review the history of the field and highlight a specific astrophysical application of the collisional Penrose process: the potential to enhance annihilation of dark matter particles in the vicinity of a supermassive black hole. Keywords black holes · ergosphere · Kerr metric 1 Introduction We begin with a brief overview of the Kerr metric for spinning, stationary black holes [1]. By far the most convenient, and thus most common form of the Kerr metric is the form derived by Boyer and Lindquist [2]. In standard spherical coor- -
The Fundamental Scales of Structures from First Principles Scott Funkhouser Department of Physics, the Citadel 171 Moultrie St., Charleston, SC, 29409
The fundamental scales of structures from first principles Scott Funkhouser Department of Physics, The Citadel 171 Moultrie St., Charleston, SC, 29409 ABSTRACT Five fundamental scales of mass follow from holographic limitations, a self-similar law for angular momentum and the basic scaling laws for a fractal universe with dimension 2. The five scales correspond to the observable universe, clusters, galaxies, stars and the nucleon. The fundamental scales form naturally a self-similar hierarchy, generating new relationships among the parameters of the nucleon, the cosmological constant and the Planck scale. There is implied a sixth fundamental scale that corresponds to the electrostatic force within an atom. Identifying the implied scale as such leads to new relationships among the fundamental charge, the mass of the electron and cosmological parameters. These considerations also suggest that structures on the scale of galaxies and larger must be bound by non- Newtonian forces. 1. Introduction The combination of three well-established components of modern physics leads to a set of critical scales for the masses of astronomical bodies and particles. Those critical scales correspond to the observable cosmos, clusters of galaxies, galaxies, solar systems and the nucleon. The three components that generate those fundamental scales are the physics of a fractal universe, a self-similar scaling law for angular momentum and holographic limits on information. In Sections 2, 3 and 4 of this work, basic relationships from those physical components are presented. In Sections 5 – 9 the fundamental structural scales are obtained by requiring consistency among those relationships. In Section 10 the critical scales of mass derived in Sections 5 – 9 are shown to form naturally a self-similar hierarchy based on powers of a pure number that is a function of fundamental constants.