Astrodynamics 2017
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
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). -
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. -
+ New Horizons
Media Contacts NASA Headquarters Policy/Program Management Dwayne Brown New Horizons Nuclear Safety (202) 358-1726 [email protected] The Johns Hopkins University Mission Management Applied Physics Laboratory Spacecraft Operations Michael Buckley (240) 228-7536 or (443) 778-7536 [email protected] Southwest Research Institute Principal Investigator Institution Maria Martinez (210) 522-3305 [email protected] NASA Kennedy Space Center Launch Operations George Diller (321) 867-2468 [email protected] Lockheed Martin Space Systems Launch Vehicle Julie Andrews (321) 853-1567 [email protected] International Launch Services Launch Vehicle Fran Slimmer (571) 633-7462 [email protected] NEW HORIZONS Table of Contents Media Services Information ................................................................................................ 2 Quick Facts .............................................................................................................................. 3 Pluto at a Glance ...................................................................................................................... 5 Why Pluto and the Kuiper Belt? The Science of New Horizons ............................... 7 NASA’s New Frontiers Program ........................................................................................14 The Spacecraft ........................................................................................................................15 Science Payload ...............................................................................................................16 -
Four New Faculty Join AE Ormsbee Professorship Endowed Online MS
Newsletter of the Department of Aerospace Engineering University of Illinois at Urbana-Champaign Vol. 17 • 2015 Upholding AE’s Tradition of Teaching Excellence PAGE 18 Four New Faculty Join AE PAGE 4 Ormsbee Professorship Endowed PAGE 14 Online MS Program Debuts PAGE 15 Inside Welcome to the 2015 Edition of the Alumni Newsletter of Faculty News Aerospace Engineering at AE Gains Four New Faculty ....................................4 Selig and Chung Earn Promotions ...............................7 Illinois Bodony Named Willett Faculty Scholar ...........................7 In last year’s newsletter, I started my introductory Bringing Aerodynamics Research to Life, Elliott Builds on Illinois’ Tradition . 8 words by reporting with great excitement that four Friend, Colleague Recalls Professor Sivier .........................9 Mission Possible: This Device Will Self-Destruct When Heated .........10 new faculty members were going to join the Depart- Chung Co-leading $1.5 Million Development of Robot Bats for ment during the 2014-15 academic year. This was Construction Site Monitoring ...............................10 the culmination of a remarkable recruitment effort Ansell Wins Young Investigator Award for Work on Dynamic Stall that our Department had never experienced in the Unsteady Flow ..........................................11 twenty or so years that I have been in AE@Illinois. AE Scientists Examine Deflecting, Exploring Asteroids ...............12 Well, I am absolutely delighted to report once again Panesi earns NASA Early Career Faculty Award for Modeling of that four more faculty members will join AE during Mars Entry .............................................13 the 2015-16 academic year to help the Department Chasiotis, Ansell and Gerhold Recognized for Advising ..............13 with its teaching and research missions in the areas of Department News space exploration and technology, aeroelasticity, big data, topology optimization and additive manufactur- Liebeck Endows Ormsbee Professorship .........................14 ing. -
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. -
Optical Navigation Preparations for New Horizons Pluto Flyby*
OPTICAL NAVIGATION PREPARATIONS FOR NEW HORIZONS PLUTO FLYBY* William M. Owen, Jr.(1), Philip J. Dumont(2), and Coralie D. Jackman(3) (1)Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive 301–121, Pasadena CA 91109–8099, 818 354–2505, [email protected] (2)KinetX, Inc., 21 W. Easy St., Simi Valley CA 93065, 805 520–8538, [email protected] (3) KinetX, Inc., 21 W. Easy St., Simi Valley CA 93065, 805 520–8539, [email protected] Abstract: The New Horizons spacecraft will encounter Pluto and its satellites in July 2015. As was the case for the Voyager encounters with Jupiter, Saturn, Uranus and Neptune, mission success will depend heavily on accurate spacecraft navigation, and accurate navigation will be impossible without the use of pictures of the Pluto system taken by the onboard cameras. We describe the preparations made by the New Horizons optical navigators: picture planning, image processing algorithms, software development and testing, and results from in-flight imaging. Keywords: New Horizons, Pluto, navigation, optical navigation, image processing 1. Introduction Traditional optical navigation (Opnav) uses a spacecraft camera to take pictures of foreground target objects against a background of catalogued reference stars. This technique was pioneered in the 1960s [1] and enabled successful navigation of the six Voyager flybys of the outer planets [2] and Cassini’s orbital operations at Saturn [3]. The New Horizons mission to Pluto will likewise use optical navigation: images will be acquired with the onboard science cameras and downlinked to Earth for processing. Optical navigation does an excellent job of determining the inertial direction to the observed targets, but it does not do at all well at determining the distance to the targets, especially if their size and surface features are not well known. -
Post-Main-Sequence Planetary System Evolution Rsos.Royalsocietypublishing.Org Dimitri Veras
Post-main-sequence planetary system evolution rsos.royalsocietypublishing.org Dimitri Veras Department of Physics, University of Warwick, Coventry CV4 7AL, UK Review The fates of planetary systems provide unassailable insights Cite this article: Veras D. 2016 into their formation and represent rich cross-disciplinary Post-main-sequence planetary system dynamical laboratories. Mounting observations of post-main- evolution. R. Soc. open sci. 3: 150571. sequence planetary systems necessitate a complementary level http://dx.doi.org/10.1098/rsos.150571 of theoretical scrutiny. Here, I review the diverse dynamical processes which affect planets, asteroids, comets and pebbles as their parent stars evolve into giant branch, white dwarf and neutron stars. This reference provides a foundation for the Received: 23 October 2015 interpretation and modelling of currently known systems and Accepted: 20 January 2016 upcoming discoveries. 1. Introduction Subject Category: Decades of unsuccessful attempts to find planets around other Astronomy Sun-like stars preceded the unexpected 1992 discovery of planetary bodies orbiting a pulsar [1,2]. The three planets around Subject Areas: the millisecond pulsar PSR B1257+12 were the first confidently extrasolar planets/astrophysics/solar system reported extrasolar planets to withstand enduring scrutiny due to their well-constrained masses and orbits. However, a retrospective Keywords: historical analysis reveals even more surprises. We now know that dynamics, white dwarfs, giant branch stars, the eponymous celestial body that Adriaan van Maanen observed pulsars, asteroids, formation in the late 1910s [3,4]isanisolatedwhitedwarf(WD)witha metal-enriched atmosphere: direct evidence for the accretion of planetary remnants. These pioneering discoveries of planetary material around Author for correspondence: or in post-main-sequence (post-MS) stars, although exciting, Dimitri Veras represented a poor harbinger for how the field of exoplanetary e-mail: [email protected] science has since matured. -
Orbital Manoeuvres
AER506 - Fall 2019 B. Vatankhahghadim Lecture 8 Orbital Manoeuvres aving studied the dynamics of orbital motion and how to describe an orbit, we will now look at how H to control and modify spacecraft’s orbits. In particular, we will study the effects of applying thrusts in various directions, and discuss a few specific manoeuvre types. Overview Recall, from Orbit Description and Determination, that an orbit is completely determined by the knowledge of r(t) and v(t) at any given time, t. To move the v ~ ~ f spacecraft from one orbit to another, thruster force is applied, which results in Δ→v v a change in v. Therefore, if a single-impulse manoeuvre is desired, the initial i ~ and final orbits shall have at least one intersection point where the thrust will be applied, as depicted in Figure 8.1. It is assumed that an instantaneous change in the velocity vector, ∆v, is ap- ~ plied via an impulsive thrust. As a result, the position vector, r, is assumed to ~ be unaltered after the burn. This is not completely accurate for real missions with long thruster on/off times, but it is sufficient for our purposes. The over- Figure 8.1: General Manoeuvre all objective of most orbital manoeuvres is to minimize the fuel consumption by minimizing ∆v = j∆vj, and/or to minimize the time taken to complete the manoeuvre. ~ General Manoeuvres Recall the constants of orbital motion from Orbital Mechanics, namely: v · v µ µ v × h r , ~ ~ − = − ; h , r × v ; e , ~ ~ − ~ 2 r 2a ~ ~ ~ ~ µ r The general approach to determining the changes in the orbital parameters as a result of a known ∆v, ap- ~ plied when the spacecraft is at r with an initial velocity of vi, involves computing the resultant velocity vector, ~ ~ vf = vi + ∆v, and determining the constants of the new orbit. -
20Th IAA SYMPOSIUM on HUMAN EXPLORATION of the SOLAR SYSTEM (A5) Human Exploration of Mars (2)
68th International Astronautical Congress 2017 Paper ID: 38609 oral 20th IAA SYMPOSIUM ON HUMAN EXPLORATION OF THE SOLAR SYSTEM (A5) Human Exploration of Mars (2) Author: Prof. Sarag Saikia Purdue University, United States, [email protected] Dr. Buzz Aldrin Buzz Aldrin Enterprises, LLC, United States, [email protected] Dr. Andrew Aldrin Florida Institute of Technology, United States, aaldrin@fit.edu Prof. James Longuski Purdue University, United States, [email protected] DESIGN OF A 50-PERSON BASE FOR PIONEERING HUMAN ACTIVITIES LEADING TO PERMANENCE ON MARS Abstract We propose a pioneering international base to support 50 explorers as the first step toward sustainable human presence on Mars via a gradual buildup of capabilities. Mars is the next tangible frontier for expanding human expansion beyond Earth and a goal for pioneering space. NASA and industry are developing the capabilities needed to send humans to an asteroid by 2025 and Mars within the 2030s| goals outlined in the NASA Authorization Act of 2010 as well as in the 2010 US National Space Policy. In October 2015, NASA released a plan outlining the next steps for the Journey to Mars. Recently SpaceX's Elon Musk outlined a plan to establish a Mars colony of up to 80,000 people with a per person trip cost of less than USD 0.5 M. Musk provides no further detailed plan as to how the SpaceX's colony will be established and operated. In this paper, we envisage that initial exploration of Mars will start off as a scientific exploration and engineering base analogous to the United States' Amundsen{Scott South Pole Station in Antarctica. -
Optical Navigation Preparations for New Horizons Pluto Flyby
OPTICAL NAVIGATION PREPARATIONS FOR NEW HORIZONS PLUTO FLYBY William M. Owen, Jr. (1) , Philip J. Dumont (2) , Coralie D. Jackman (3), and Eric Carranza (4) (1) Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena CA 91109-8099, (818) 354-2505, [email protected] (2)KinetX, Inc., 21 W. Easy St. #108, Simi Valley CA 93065, (805) 520-8538, [email protected] (3)KinetX, Inc., 21 W. Easy St. #108, Simi Valley CA 93065, (805) 520-8539, [email protected] (4)KinetX, Inc., 21 W. Easy St. #108, Simi Valley CA 93065, (805) 520-8827, [email protected] Keywords: optical navigation, New Horizons, Pluto ABSTRACT The New Horizons spacecraft will encounter Pluto and its satellites in July 2015. As was the case for the Voyager encounters with Jupiter, Saturn, Uranus and Neptune, mission success will depend heavily on accurate spacecraft navigation, and accurate navigation will be impossible without the use of pictures of the Pluto system taken by the onboard cameras. Traditional optical navigation, taking exposures of foreground target objects against a background of catalogued reference stars, does an excellent job of determining the inertial direction to those targets. It does not do at all well at determining the distance to the targets, especially if their size and surface features are not well known. For a flyby encounter such as New Horizons at Pluto, approach imaging therefore determines the location of the incoming asymptote of the spacecraft’s hyperbolic trajectory well, but it does little to improve the knowledge of the time of closest approach.