PLANETARY SATELLITES - Storming Media

Tidal Dissipation Compared To Seismic Dissipation: In Small Bodies, Earths, And Super-Earths

20 Feb 2012

22 pages

Authors: Michael Efroimsky; NAVAL OBSERVATORY WASHINGTON DC

The full text of this report is available for sale.

While the seismic quality factor and phase lag are defined solely by the bulk properties of the mantle, their tidal counterparts are determined by both the bulk properties and the size effect (self-gravitation of a body as a whole). For a qualitative estimate, we model the body with a homogeneous sphere, and express the tidal phase lag through the lag in a sample of material. Although simplistic, our model is ...

A New Astrometric Reduction of Photographic Plates Using the DAMIAN Digitizer: Improving the Dynamics of the Jovian System

2011

9 pages

Authors: V. Robert; J. De Cuyper; J. Arlot; G. de Decker; J. Guibert; V. Lainey; D. Pascu; L. Winter; N. Zacharias; NAVAL OBSERVATORY WASHINGTON DC

The astrometric monitoring of the natural planetary satellites is an important step to assess the formation and the evolution of these systems. However, in order to quantify relevant gravitational effects such as tidal forces, it is necessary to have very accurate observations over a long time interval. Unfortunately, the accuracy is decreasing as one considers older observations. To solve this issue, digitizing of old photographic plates is an attractive method, ...

Fundamental Astronomy (Astronomie Fondamentale)

Jan-2009

5 pages

Authors: Jan Vondrak; NAVAL OBSERVATORY WASHINGTON DC

Division I provides a focus for astronomers studying a wide range of problems related to fundamental physical phenomena such as time, the inertial reference frame, positions and proper motions of celestial objects and precise dynamical computation of the motions of bodies in stellar or planetary systems in the Universe.

Long-Term Evolution of Orbits About a Precessing Oblate Planet: 3. A Semianalytical and a Purely Numerical Approach

NOV 2007

33 pages

Authors: Pini Gurfil; Valery Lainey; Michael Efroimsky; NAVAL OBSERVATORY WASHINGTON DC

Construction of an accurate theory of orbits about a precessing and nutating oblate planet, in terms of osculating elements defined in a frame associated with the equator of date, was started in Efroimsky and Goldreich (2004) and Efroimsky (2004, 2005, 2006a, b). Here we continue this line of research by combining that analytical machinery with numerical tools. Our model includes three factors: the J2 of the planet, its nonuniform equinoctial ...

On the Search for Transits of the Planets Orbiting Gliese 876

10 DEC 2006

9 pages

Authors: P. D. Shankland; E. J. Rivera; A. Price; F. Ringwald; G. W. Henry; P. McGee; B. Carter; S. Lee; J. Biggs; B. Monard; NAVAL OBSERVATORY WASHINGTON DC

We report the results of a globally coordinated photometric campaign to search for transits by the P~30 day and P~60 day outer planets of the three-planet system orbiting the nearby M dwarf Gl 876. These two planets experience strong mutual perturbations, which necessitate the use of a dynamical (four-body) model to compute transit ephemerides for the system. Our photometric data have been collected from published archival sources, as well as ...

Improving the Visual Magnitudes of the Planets in The Astronomical Almanac. I. Mercury and Venus

2005

18 pages

Authors: James L. Hilton; NAVAL OBSERVATORY WASHINGTON DC

Estimates for the apparent V magnitudes of the planets currently published in The Astronomical Almanac are based on phase coefficients presented in Harris (1961) along with values for V(1,0) from de Vaucouleurs (1970). Work is currently underway to update these values. The apparent V magnitudes of Mercury and Venus are examined here. This analysis provides new values for V(1, 0) derived from a variety of V photometric data sets for ...

Long-Term Evolution of Orbits about a Precessing Oblate Planet: 1. The Case of Uniform Precession

26 AUG 2004

57 pages

Authors: Michael Efroimsky; NAVAL OBSERVATORY WASHINGTON DC

It was believed until very recently that a near-equatorial satellite would always keep up with the planet's equator (with oscillations in inclination, but without a secular drift). This misconception originated from a wrong interpretation of a (mathematically correct) result obtained in terms of non-osculating orbital elements. A similar analysis carried out in the language of osculating elements will endow the planetary equations with some extra terms caused by the planet's ...

Broadcast vs Precise GPS Ephemerides: A Historical Perspective

MAR 2002

Authors: David L. Warren; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT

The full text of this report is not available and therefore is not for sale. This information is provided for reference purposes only.

The Global Positioning System (GPS) Operational Control Segment (OCS) generates predicted satellite ephemerides and clock corrections that are broadcast in the navigation message and used by receivers to estimate real-time satellite position and clock corrections for use in navigation solutions. Any errors in these ephemerides will directly impact the accuracy of GPS based positioning. This study compares the satellite position computed using broadcast ephemerides with the precise position provided by ...

Celestial Background Scene Descriptor: Final Report

FEB 2001

89 pages

Authors: P. V. Noah; M. A. Noah; MISSION RESEARCH CORP SANTA BARBARA CA

This report summarizes the results of the Celestial Background Scene Descriptor (CBSD) program. The goal of the CBSD program is to design, build, and validate a suite of FORTRAN codes that simulates the flux from the celestial background, in support of DoD developed optical and infrared sensor systems, realistic scenario generation, and the development of clutter removal algorithms. Components of the CBSD suite are CBSKY4 - stellar point sources (both ...

New Research in Sky Surveillance - Interpretation of Low-Luminosity Objects

15 DEC 2000

17 pages

Authors: Robert S. McMillan; STEWARD OBSERVATORY TUCSON AZ

Spacewatch is an exploration of the whole solar system for minor planets and comets, from the inner solar system to beyond Neptune's orbit. During this report period, Spacewatch discovered 23 Earth-approachers (EAs), 9, 910 main belt asteroids (MBAs), a new satellite of Jupiter, 2 comets, 9 Centaurs or scattered-disk objects, and 6 Trans-Neptunian Objects (TNOs). Spacewatch made a new estimate of the number of km-sized EAs, from which it has ...

Adaptive Optics Imaging of Solar System Objects

07 FEB 2000

5 pages

Authors: Francois Roddier; HAWAII UNIV HONOLULU INST FOR ASTRONOMY

Adaptive optics observation of Saturn's ring plane crossing, Neptunes atmospheric activity, volcanoes on 10, and Titan. Photometry of Pluto and Charon. Surface mapping of Ceres, Pallas and Vesta. Detection of Neptune's arcs and dark satellites.

Satellite Attitude Control Using Magnetic Torquers, a Periodic Time- Varying Control Problem

26 JAN 2000

25 pages

Authors: Mark L. Psiaki; Raffaello D'Andrea; CORNELL UNIV ITHACA NY

Satellite attitude controllers have been designed for a rigid spacecraft whose only actuators are magnetic torque rods. This effort's goals have been to develop a new class of lightweight, moderate accuracy attitude controllers and to evaluate and further develop general methods for the control of time varying systems. Three different classes of controllers have been developed and simulation tested. one based on linear quadratic regulator ...

Orbit Analysis Tools Software Version 1 for Windows User's Guide

30 JUN 1999

87 pages

Authors: Jay W. Middour; Alan S. Hope; Jenna L. Cox; Robin K. Llewellyn; NAVAL RESEARCH LAB WASHINGTON DC

The Orbit Analysis Tools Software (OATS) is a mission planning and analysis tool for earth-orbiting satellites. OATS evolved from a collection of software tools developed by the Astrodynamics and Space Applications Office of the Naval Center for Space Technology (NCST), located at the Naval Research Laboratory (NRL) in Washington, DC. There have been three previous versions of OATS that are available to the public for use on a Macintosh computer. ...

Orbit Determination from Visual Sightings: An Investigation of Two Angles-Only Orbit Determination Processes Including a Science Activity for Middle and High School Students

26 OCT 1998

51 pages

Authors: Lee S. Dewald Jr; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH

This project will investigate the possibilities of determining the orbit of a satellite from the data obtained by observing the satellite passing across the sky. With simple tools such as a stopwatch, compass, and star map or camera, I believe that the orbit of a satellite may be determined by an angles only approach. In addition, young students, of middle school age and older, could be exposed to the fundamentals ...

Infrared Celestial Backgrounds Studies, Volume 1. Summary of Project Goals and Accomplishments

10 SEP 1998

89 pages

Authors: Russell G. Walker; Martin Cohen; VANGUARD RESEARCH LAB INC PASADENA CA

The purpose of this program was to extend and improve the present capability to predict celestial phenomenology pertinent to the design and successful operation of space based surveillance systems using the ultraviolet, optical, and infrared spectral regions. We pursued this goal through analysis and application of existing datasets and, in particular, by analysis of new satellite measurements that became available during the course of the project. Our work was concentrated ...

Infrared Celestial Backgrounds Studies, Volume 2. A Radiometric All-Sky Network of Absolutely Calibrated Stellar Spectra

10 SEP 1998

192 pages

Authors: Russell G. Walker; Martin Cohen; VANGUARD RESEARCH LAB INC PASADENA CA

Orbit Analysis Tools Software for the Macintosh (Version 5) Users Manual

18 JUL 1997

165 pages

Authors: Jay W. Middour; Alan S. Hope; Steven S. McLaughlin; NAVAL RESEARCH LAB WASHINGTON DC ASTRODYNAMICS AND SPACE APPLICATIONS OFFICE

The Orbit Analysis Tools Software (OATS) program has been revised and expanded. The program's function is to perform satellite mission and coverage analysis using numerical and graphical techniques to analyze and display earth coverage data and ground-to-satellite geometrical parameters. Satellite ephemerides can be computed by any one of four orbit propagators provided with the program or imported from an external source. Six commonly utilized map projections are available to plot ...

Electric Propulsion For Spacecraft Applications

DEC 96

Authors: Jeff D. Filliben; CHEMICAL PROPULSION INFORMATION AGENCY COLUMBIA MD

The purpose of this review and an accompanying review, CPTR 96-65 Electric Thruster Systems, is to present an overview of the current field of electric propulsion technology. This review focuses on operational issues associated with the use of electric propulsion systems and the current and proposed mission applications. More than 200 electric propulsion devices have been used on about 100 spacecraft over the last 32 years and a significant increase ...

Spacecraft Interactions Modeling and Post-Mission Data Analysis

15 AUG 96

72 pages

Authors: N. A. Bonito; K. H. Bounar; W. J. McNeil; C. J. Roth; M. F. Tautz; RADEX INC BEDFORD MA

Software systems were designed and developed for data management, data acquisition, interactive visualization and analysis of solar arrays, tethered objects, and large object space plasma interactions. Simulations were performed and models were constructed for spacecraft interactions with the ambient environment. In Support of these analyses, models for satellite ephemeris, attitude determination, magnetic fields, atmospheric composition, and particle precipitation were designed and developed, using PL computational resources extensively. The SPREE experiments ...

High Pressure Earth Storable Rocket Technology Program. Basic Program

MAR 95

78 pages

Authors: M. L. Chazen; D. Sicher; D. Huang; T. Mueller; TRW SPACE AND TECHNOLOGY GROUP REDONDO BEACH CA

The HIPES Program was conducted for NASA-LeRC by TRW. The Basic Program consisted of system studies, design of testbed engine, fabrication and testing of engine. Studies of both pressure-fed and pump-fed systems were investigated for N204 and both MMH and N2H4 fuels with the result that N2H4 provides the maximum payload for all satellites over MMH. The higher pressure engine offers improved performance with smaller envelope and associated weight savings. ...

CBSD: The Celestial Background Scene Descriptor.

JAN 1993

Authors: J. P. Kennealy; P. V. Noah; E. F. Tedesco; R. M. Cutri; S. F. Dermott; MISSION RESEARCH CORP NASHUA NH

This report documents the Celestial Background Scene Descriptor (CBSD) program which is a suite of models to simulate the radiance of astronomical sources. The models simulate the contribution of the celestial background in the wavelength regime 2 to 30 micrometers with a positional accuray of 2 arcseconds. The output of the models are tables and images suitable for use in sensor simulation. The CBAMP model calculates the thermal radiance and ...

Diamond Based Microelectronics

NOV 1992

4 pages

Authors: J. R. Zeidler; C. A. Hewett; NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV SAN DIEGO CA

The need for electronic devices which will reliable operate in the temperature range from 400 to 600 deg C has made it essential to look beyond conventional electronic materials such as silicon or gallium arsenide. Devices based on these materials are presently able to meet a limited number of elevated temperature demands, but only with the added cost and complexity of an environmental cooling system. Sensors and control devices mounted ...

A Technique for Capture Analysis of Low Thrust Missions in a Planetary System

DEC 87

Authors: Charles J. Poole; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

The purpose of this study was to develop a tool to analyze capture trajectories in a planetary system for a spacecraft using low thrust propulsion. The reason was to see whether or not it was possible to use a low thrust vehicle rather than a chemically propelled spacecraft to survey the moons of a planet. A single pass tool for analyzing capture trajectories about a planet's moons for a spacecraft ...

Periodic Orbits Around a Satellite Modelled as a Triaxial Ellipsoid

DEC 87

Authors: Rodney A. Werner; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

There are planetary satellites, particularly Phobos, which can be modeled s triaxial ellipsoids. To study orbital dynamics of a mass near such a satellite, Hamilton's canonical equations are developed and used to numerically evaluate the existence of periodic orbits around the satellite. Calculations were also done to check the stability of these orbits by evaluating the Poincare exponents. for Phobos, periodic orbits were found in Phobos's orbital plane from near ...

Findings on Rings and Inner Satellites of Saturn by Pioneer 11

MAR 1982

Authors: James A. Van Allen; IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY

The introductory part of this paper gives a short account of the theory of absorption by planetary rings and satellites of energetic charged particles that are trapped in a planet's magnetic field and describes the observable consequences of such absorption processes. The University of Iowa observations of absorption features during Pioneer 11's passage through Saturn's inner radiation belt on 1 September 1979 are critically reanalyzed and related to other evidence ...

A Mathematical Description of the Low-Altitude Satellite Mission Planning Tool (LAMP)

JAN 1982

Authors: A. D. Parks; NAVAL SURFACE WEAPONS CENTER DAHLGREN VA

The Low-Altitude Mission Planning tool is capable of providing accurate long-term (approx. 90 day) predictions of key Keplerian orbit parameters and related quantities for one or two low-altitude satellites. Analytically modeled averaged variational equations are used to represent the effects of the geopotential oblateness upon satellite motion. Satellite drag perturbations are taken into account using a hybrid drag decay model which accounts for atmospheric oblateness and diurnal density variation. Adjustments ...

Global Positioning System Time Transfer Receiver (GPS/TTR) Prototype Design and Initial Test Evaluation

Dec-1981

32 pages

Authors: J Oaks; A Frank; S Falvey; M Lister; J Buisson; C Wardrip; H Warren; NAVAL RESEARCH LAB WASHINGTON DC

Time transfer equipment and techniques used with the NRL Navigation Technology Satellites have been modified and extended for use with the GPS satellites . A prototype receiver was built and field tested at NASA's Kennedy Spaceflight Center. The receiver uses the GPS L1 link at 1575 MHz with C/A code only to resolve a measured range to the satellite . A theoretical range is computed from the satellite ephemeris transmitted ...

Narrowband Electromagnetic Emissions from Saturn's Magnetosphere

21 MAY 1981

Authors: D. A. Gurnett; W. S. Kurth; F. L. Scarf; IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY

During the Voyager 1 flyby of Saturn a series of narrowband electromagnetic emissions were detected by the plasma wave instrument coming from the inner region of the magnetosphere in the frequency range from 3 to 30 kHz. These emissions have many close similarities to continuum radiation detected in the Earth's magnetosphere and narrowband kilometric radiation (nKOM) detected in the Jovian magnetosphere. Based on the close similarity to the terrestrial continuum ...

The Energetic Charged Particle Absorption Signature of Mimas.

19 JUL 1980

Authors: J. A. Van Allen; M. F. Thomsen; B. A. Randall; IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY

Data are presented for a one-minute dip in electron intensity that was observed coherently by four different detectors at 1546:51 ERT on DOY 244/1979 as Pioneer 11 crossed the orbit of Mimas inbound during its encounter with the Saturn system. By a detailed analysis, we show that this absorption microsignature in electron intensity is plausibly attributable to the particle sweeping effect of Mimas; the radial width of the signature is ...

Satellite Sweeping of Electrons and Protons in Saturn's Inner Magnetosphere.

JUL 1980

Authors: R. Rairden; IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY

In a computer simulation particles of various energies were followed along their orbits to determine the probability of their absorption during one encounter with an inner satellite of Saturn, giving special consideration to leapfrog and corkscrew escape factors. The time interval between encounters may then be used to yield a measure of particle lifetimes in given satellite L shells. Energy and pitch angle dependence of satellite sweeping efficiency is illustrated. ...

Control Networks for the Galilean Satellites: November 1979,

NOV 1979

Authors: Merton E. Davies; Thomas A. Hauge; Frank Y. Katayama; James A. Roth; RAND CORP SANTA MONICA CA

Pictures of the four Galilean satellites were taken as the two Voyager spacecraft approached Jupiter during March and July 1979, and nearly full coverage of all the satellites was obtained by each flyby as the satellites rotated in front of the cameras. High-resolution mosaics of the satellites were obtained during the periods of closest encounter. The faceplates of the vidicon cameras have reseaux of 202 points to permit removal of ...

Jupiter's Radiation Belts.

28 NOV 1978

Authors: Michael Schulz; AEROSPACE CORP EL SEGUNDO CALIF IVAN A GETTING LABS

Close encounters of Pioneer 10 (December 1973) and Pioneer 11 (December 1974) with the planet Jupiter provided the first in situ observations of zenomagnetically trapped particle radiation. These observations have stimulated continuing theoretical efforts to understand the reported findings and to extrapolate from them to other planets and other epochs. The observed radiation belts seem to be populated by radial diffusion from an external source. The diffusion coefficient seems to ...

Initial Conditions for an Orbital Resonance in a Satellite System.

01 JUN 1978

Authors: Stephen M. Hopkins; NAVAL ACADEMY ANNAPOLIS MD

This project undertook to examine the conditions of the 3/2 resonance between the planets of Pluto and Neptune and try to determine whether it was possible for Pluto to have escaped from Neptune and became his moon. The writer uses numerical integration and computer programs to establish that the Neptune and Pluto are in resonance, consequently they would never come close enough to one another for Pluto to be a ...

SECULAR CHANGES IN THE SOLAR SYSTEM

FEB 1963

82 pages

Authors: Peter Goldreich; CORNELL UNIV ITHACA NY

Contents: On the Inclination of Satellite Orbits About an Oblate Precessing Planet; On the Eccentricity of Satellite Orbits in the Solar System; An Explanation of the Frequent Occurrence of Near-Commensurate Mean Motions in the Solar System; and Literature Cited.