Geocentric Spherical Surfaces Emulating the Geostationary Orbit at Any Latitude with Zenith Links
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Astrodynamics
Politecnico di Torino SEEDS SpacE Exploration and Development Systems Astrodynamics II Edition 2006 - 07 - Ver. 2.0.1 Author: Guido Colasurdo Dipartimento di Energetica Teacher: Giulio Avanzini Dipartimento di Ingegneria Aeronautica e Spaziale e-mail: [email protected] Contents 1 Two–Body Orbital Mechanics 1 1.1 BirthofAstrodynamics: Kepler’sLaws. ......... 1 1.2 Newton’sLawsofMotion ............................ ... 2 1.3 Newton’s Law of Universal Gravitation . ......... 3 1.4 The n–BodyProblem ................................. 4 1.5 Equation of Motion in the Two-Body Problem . ....... 5 1.6 PotentialEnergy ................................. ... 6 1.7 ConstantsoftheMotion . .. .. .. .. .. .. .. .. .... 7 1.8 TrajectoryEquation .............................. .... 8 1.9 ConicSections ................................... 8 1.10 Relating Energy and Semi-major Axis . ........ 9 2 Two-Dimensional Analysis of Motion 11 2.1 ReferenceFrames................................. 11 2.2 Velocity and acceleration components . ......... 12 2.3 First-Order Scalar Equations of Motion . ......... 12 2.4 PerifocalReferenceFrame . ...... 13 2.5 FlightPathAngle ................................. 14 2.6 EllipticalOrbits................................ ..... 15 2.6.1 Geometry of an Elliptical Orbit . ..... 15 2.6.2 Period of an Elliptical Orbit . ..... 16 2.7 Time–of–Flight on the Elliptical Orbit . .......... 16 2.8 Extensiontohyperbolaandparabola. ........ 18 2.9 Circular and Escape Velocity, Hyperbolic Excess Speed . .............. 18 2.10 CosmicVelocities -
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 -
AFSPC-CO TERMINOLOGY Revised: 12 Jan 2019
AFSPC-CO TERMINOLOGY Revised: 12 Jan 2019 Term Description AEHF Advanced Extremely High Frequency AFB / AFS Air Force Base / Air Force Station AOC Air Operations Center AOI Area of Interest The point in the orbit of a heavenly body, specifically the moon, or of a man-made satellite Apogee at which it is farthest from the earth. Even CAP rockets experience apogee. Either of two points in an eccentric orbit, one (higher apsis) farthest from the center of Apsis attraction, the other (lower apsis) nearest to the center of attraction Argument of Perigee the angle in a satellites' orbit plane that is measured from the Ascending Node to the (ω) perigee along the satellite direction of travel CGO Company Grade Officer CLV Calculated Load Value, Crew Launch Vehicle COP Common Operating Picture DCO Defensive Cyber Operations DHS Department of Homeland Security DoD Department of Defense DOP Dilution of Precision Defense Satellite Communications Systems - wideband communications spacecraft for DSCS the USAF DSP Defense Satellite Program or Defense Support Program - "Eyes in the Sky" EHF Extremely High Frequency (30-300 GHz; 1mm-1cm) ELF Extremely Low Frequency (3-30 Hz; 100,000km-10,000km) EMS Electromagnetic Spectrum Equitorial Plane the plane passing through the equator EWR Early Warning Radar and Electromagnetic Wave Resistivity GBR Ground-Based Radar and Global Broadband Roaming GBS Global Broadcast Service GEO Geosynchronous Earth Orbit or Geostationary Orbit ( ~22,300 miles above Earth) GEODSS Ground-Based Electro-Optical Deep Space Surveillance -
Arxiv:1505.07033V2 [Astro-Ph.IM] 4 Sep 2015
September 7, 2015 0:46 manuscript Journal of Astronomical Instrumentation c World Scientific Publishing Company A CUBESAT FOR CALIBRATING GROUND-BASED AND SUB-ORBITAL MILLIMETER-WAVE POLARIMETERS (CALSAT) Bradley R. Johnson1, Clement J. Vourch2, Timothy D. Drysdale2, Andrew Kalman3, Steve Fujikawa4, Brian Keating5 and Jon Kaufman5 1Department of Physics, Columbia University, New York, NY 10027, USA 2School of Engineering, University of Glasgow, Glasgow, Scotland G12 8QQ, UK 3Pumpkin, Inc., San Francisco, CA 94112, USA 4Maryland Aerospace Inc., Crofton, MD 21114, USA 5Department of Physics, University of California, San Diego, CA 92093-0424, USA Received (to be inserted by publisher); Revised (to be inserted by publisher); Accepted (to be inserted by publisher); We describe a low-cost, open-access, CubeSat-based calibration instrument that is designed to support ground- based and sub-orbital experiments searching for various polarization signals in the cosmic microwave background (CMB). All modern CMB polarization experiments require a robust calibration program that will allow the effects of instrument-induced signals to be mitigated during data analysis. A bright, compact, and linearly polarized astrophysical source with polarization properties known to adequate precision does not exist. Therefore, we designed a space-based millimeter-wave calibration instrument, called CalSat, to serve as an open-access calibrator, and this paper describes the results of our design study. The calibration source on board CalSat is composed of five \tones" with one each at 47.1, 80.0, 140, 249 and 309 GHz. The five tones we chose are well matched to (i) the observation windows in the atmospheric transmittance spectra, (ii) the spectral bands commonly used in polarimeters by the CMB community, and (iii) The Amateur Satellite Service bands in the Table of Frequency Allocations used by the Federal Communications Commission. -
Pointing Analysis and Design Drivers for Low Earth Orbit Satellite Quantum Key Distribution Jeremiah A
Air Force Institute of Technology AFIT Scholar Theses and Dissertations Student Graduate Works 3-24-2016 Pointing Analysis and Design Drivers for Low Earth Orbit Satellite Quantum Key Distribution Jeremiah A. Specht Follow this and additional works at: https://scholar.afit.edu/etd Part of the Information Security Commons, and the Space Vehicles Commons Recommended Citation Specht, Jeremiah A., "Pointing Analysis and Design Drivers for Low Earth Orbit Satellite Quantum Key Distribution" (2016). Theses and Dissertations. 451. https://scholar.afit.edu/etd/451 This Thesis is brought to you for free and open access by the Student Graduate Works at AFIT Scholar. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of AFIT Scholar. For more information, please contact [email protected]. POINTING ANALYSIS AND DESIGN DRIVERS FOR LOW EARTH ORBIT SATELLITE QUANTUM KEY DISTRIBUTION THESIS Jeremiah A. Specht, 1st Lt, USAF AFIT-ENY-MS-16-M-241 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio DISTRIBUTION STATEMENT A. APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. The views expressed in this thesis are those of the author and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the United States Government. This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. AFIT-ENY-MS-16-M-241 POINTING ANALYSIS AND DESIGN DRIVERS FOR LOW EARTH ORBIT SATELLITE QUANTUM KEY DISTRIBUTION THESIS Presented to the Faculty Department of Aeronautics and Astronautics Graduate School of Engineering and Management Air Force Institute of Technology Air University Air Education and Training Command In Partial Fulfillment of the Requirements for the Degree of Master of Science in Space Systems Jeremiah A. -
Up, Up, and Away by James J
www.astrosociety.org/uitc No. 34 - Spring 1996 © 1996, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112. Up, Up, and Away by James J. Secosky, Bloomfield Central School and George Musser, Astronomical Society of the Pacific Want to take a tour of space? Then just flip around the channels on cable TV. Weather Channel forecasts, CNN newscasts, ESPN sportscasts: They all depend on satellites in Earth orbit. Or call your friends on Mauritius, Madagascar, or Maui: A satellite will relay your voice. Worried about the ozone hole over Antarctica or mass graves in Bosnia? Orbital outposts are keeping watch. The challenge these days is finding something that doesn't involve satellites in one way or other. And satellites are just one perk of the Space Age. Farther afield, robotic space probes have examined all the planets except Pluto, leading to a revolution in the Earth sciences -- from studies of plate tectonics to models of global warming -- now that scientists can compare our world to its planetary siblings. Over 300 people from 26 countries have gone into space, including the 24 astronauts who went on or near the Moon. Who knows how many will go in the next hundred years? In short, space travel has become a part of our lives. But what goes on behind the scenes? It turns out that satellites and spaceships depend on some of the most basic concepts of physics. So space travel isn't just fun to think about; it is a firm grounding in many of the principles that govern our world and our universe. -
Multisatellite Determination of the Relativistic Electron Phase Space Density at Geosynchronous Orbit: Methodology and Results During Geomagnetically Quiet Times Y
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110, A10210, doi:10.1029/2004JA010895, 2005 Multisatellite determination of the relativistic electron phase space density at geosynchronous orbit: Methodology and results during geomagnetically quiet times Y. Chen, R. H. W. Friedel, and G. D. Reeves Los Alamos National Laboratory, Los Alamos, New Mexico, USA T. G. Onsager NOAA, Boulder, Colorado, USA M. F. Thomsen Los Alamos National Laboratory, Los Alamos, New Mexico, USA Received 10 November 2004; revised 20 May 2005; accepted 8 July 2005; published 20 October 2005. [1] We develop and test a methodology to determine the relativistic electron phase space density distribution in the vicinity of geostationary orbit by making use of the pitch-angle resolved energetic electron data from three Los Alamos National Laboratory geosynchronous Synchronous Orbit Particle Analyzer instruments and magnetic field measurements from two GOES satellites. Owing to the Earth’s dipole tilt and drift shell splitting for different pitch angles, each satellite samples a different range of Roederer L* throughout its orbit. We use existing empirical magnetic field models and the measured pitch-angle resolved electron spectra to determine the phase space density as a function of the three adiabatic invariants at each spacecraft. Comparing all satellite measurements provides a determination of the global phase space density gradient over the range L* 6–7. We investigate the sensitivity of this method to the choice of the magnetic field model and the fidelity of the instrument intercalibration in order to both understand and mitigate possible error sources. Results for magnetically quiet periods show that the radial slopes of the density distribution at low energy are positive, while at high energy the slopes are negative, which confirms the results from some earlier studies of this type. -
Broadband: Number of Retail Broadband Internet Connections Cable + DSL
OPTA Public version Broadband: Number of retail broadband internet connections cable + DSL 6.000 5.000 4.000 3.000 2.000 number of connections x 1,000 1.000 0 Change 30-09-2006 31-12-2006 31-03-2007 30-06-2007 30-09-2007 31-12-2007 31-03-2008 30-06-2008 07Q4/06Q5 Total number of retail connections 4.779 4.955 5.219 5.301 5.407 5.590 5.659 5.703 7,6% Number of DSL connections 2.916 3.017 3.187 3.224 3.268 3.396 3.442 3.470 7,6% Number of cable connections 1.863 1.938 2.032 2.077 2.139 2.194 2.216 2.233 7,5% Based on figures from BBNED, CAIW, DELTA, EASYNET, KPN, ONLINE, SCARLET, TELE2, UPC, VERIZON and ZIGGO. Based on questions 3_A3_5_2, 3_A3_5_3, 3_B_8_1 and 3_B_8_2 of the SMM. OPTA Public version Broadband: Market shares retail broadband internet connections cable + DSL (2008Q2) 60% 50% 40% 30% 20% 10% 0% D A T 2 C O r IW PN G LT NET K LE UP the BNE CA Y NLINE E IG O B DE T Z AS O CARLE ERIZON E S V 30-09-2006 31-12-2006 31-03-2007 30-06-2007 30-09-2007 31-12-2007 31-03-2008 30-06-2008 @HOME [10-20%] [10-20%] [10-20%] [10-20%] [10-20%] [10-20%] - - BBNED [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] CAIW [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] CASEMA [5-10%] [5-10%] [5-10%] [5-10%] [5-10%] [5-10%] - - DELTA [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] EASYNET [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] KPN [40-50%] [40-50%] [40-50%] [40-50%] [40-50%] [40-50%] [40-50%] [40-50%] MULTIKABEL [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] - - ONLINE [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] SCARLET [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] TELE2 [0-5%] [5-10%] [0-5%] [5-10%] [5-10%] [5-10%] [5-10%] [5-10%] TISCALI [0-5%] [0-5%] [0-5%] - - - - - UPC [10-20%] [10-20%] [10-20%] [10-20%] [10-20%] [10-20%] [10-20%] [10-20%] VERIZON - [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] ZIGGO - - - - - - [20-30%] [20-30%] Other [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] [0-5%] Based on figures from BBNED, CAIW, DELTA, EASYNET, KPN, ONLINE, SCARLET, TELE2, UPC, VERIZON and ZIGGO. -
Mission Design for the Lunar Reconnaissance Orbiter
AAS 07-057 Mission Design for the Lunar Reconnaissance Orbiter Mark Beckman Goddard Space Flight Center, Code 595 29th ANNUAL AAS GUIDANCE AND CONTROL CONFERENCE February 4-8, 2006 Sponsored by Breckenridge, Colorado Rocky Mountain Section AAS Publications Office, P.O. Box 28130 - San Diego, California 92198 AAS-07-057 MISSION DESIGN FOR THE LUNAR RECONNAISSANCE ORBITER † Mark Beckman The Lunar Reconnaissance Orbiter (LRO) will be the first mission under NASA’s Vision for Space Exploration. LRO will fly in a low 50 km mean altitude lunar polar orbit. LRO will utilize a direct minimum energy lunar transfer and have a launch window of three days every two weeks. The launch window is defined by lunar orbit beta angle at times of extreme lighting conditions. This paper will define the LRO launch window and the science and engineering constraints that drive it. After lunar orbit insertion, LRO will be placed into a commissioning orbit for up to 60 days. This commissioning orbit will be a low altitude quasi-frozen orbit that minimizes stationkeeping costs during commissioning phase. LRO will use a repeating stationkeeping cycle with a pair of maneuvers every lunar sidereal period. The stationkeeping algorithm will bound LRO altitude, maintain ground station contact during maneuvers, and equally distribute periselene between northern and southern hemispheres. Orbit determination for LRO will be at the 50 m level with updated lunar gravity models. This paper will address the quasi-frozen orbit design, stationkeeping algorithms and low lunar orbit determination. INTRODUCTION The Lunar Reconnaissance Orbiter (LRO) is the first of the Lunar Precursor Robotic Program’s (LPRP) missions to the moon. -
Positioning: Drift Orbit and Station Acquisition
Orbits Supplement GEOSTATIONARY ORBIT PERTURBATIONS INFLUENCE OF ASPHERICITY OF THE EARTH: The gravitational potential of the Earth is no longer µ/r, but varies with longitude. A tangential acceleration is created, depending on the longitudinal location of the satellite, with four points of stable equilibrium: two stable equilibrium points (L 75° E, 105° W) two unstable equilibrium points ( 15° W, 162° E) This tangential acceleration causes a drift of the satellite longitude. Longitudinal drift d'/dt in terms of the longitude about a point of stable equilibrium expresses as: (d/dt)2 - k cos 2 = constant Orbits Supplement GEO PERTURBATIONS (CONT'D) INFLUENCE OF EARTH ASPHERICITY VARIATION IN THE LONGITUDINAL ACCELERATION OF A GEOSTATIONARY SATELLITE: Orbits Supplement GEO PERTURBATIONS (CONT'D) INFLUENCE OF SUN & MOON ATTRACTION Gravitational attraction by the sun and moon causes the satellite orbital inclination to change with time. The evolution of the inclination vector is mainly a combination of variations: period 13.66 days with 0.0035° amplitude period 182.65 days with 0.023° amplitude long term drift The long term drift is given by: -4 dix/dt = H = (-3.6 sin M) 10 ° /day -4 diy/dt = K = (23.4 +.2.7 cos M) 10 °/day where M is the moon ascending node longitude: M = 12.111 -0.052954 T (T: days from 1/1/1950) 2 2 2 2 cos d = H / (H + K ); i/t = (H + K ) Depending on time within the 18 year period of M d varies from 81.1° to 98.9° i/t varies from 0.75°/year to 0.95°/year Orbits Supplement GEO PERTURBATIONS (CONT'D) INFLUENCE OF SUN RADIATION PRESSURE Due to sun radiation pressure, eccentricity arises: EFFECT OF NON-ZERO ECCENTRICITY L = difference between longitude of geostationary satellite and geosynchronous satellite (24 hour period orbit with e0) With non-zero eccentricity the satellite track undergoes a periodic motion about the subsatellite point at perigee. -
GPS Applications in Space
Space Situational Awareness 2015: GPS Applications in Space James J. Miller, Deputy Director Policy & Strategic Communications Division May 13, 2015 GPS Extends the Reach of NASA Networks to Enable New Space Ops, Science, and Exploration Apps GPS Relative Navigation is used for Rendezvous to ISS GPS PNT Services Enable: • Attitude Determination: Use of GPS enables some missions to meet their attitude determination requirements, such as ISS • Real-time On-Board Navigation: Enables new methods of spaceflight ops such as rendezvous & docking, station- keeping, precision formation flying, and GEO satellite servicing • Earth Sciences: GPS used as a remote sensing tool supports atmospheric and ionospheric sciences, geodesy, and geodynamics -- from monitoring sea levels and ice melt to measuring the gravity field ESA ATV 1st mission JAXA’s HTV 1st mission Commercial Cargo Resupply to ISS in 2008 to ISS in 2009 (Space-X & Cygnus), 2012+ 2 Growing GPS Uses in Space: Space Operations & Science • NASA strategic navigation requirements for science and 20-Year Worldwide Space Mission space ops continue to grow, especially as higher Projections by Orbit Type* precisions are needed for more complex operations in all space domains 1% 5% Low Earth Orbit • Nearly 60%* of projected worldwide space missions 27% Medium Earth Orbit over the next 20 years will operate in LEO 59% GeoSynchronous Orbit – That is, inside the Terrestrial Service Volume (TSV) 8% Highly Elliptical Orbit Cislunar / Interplanetary • An additional 35%* of these space missions that will operate at higher altitudes will remain at or below GEO – That is, inside the GPS/GNSS Space Service Volume (SSV) Highly Elliptical Orbits**: • In summary, approximately 95% of projected Example: NASA MMS 4- worldwide space missions over the next 20 years will satellite constellation. -
De Markten Voor De Doorgifte En Ontvangst Van Omroepsignalen
De markten voor de doorgifte en ontvangst van omroepsignalen *** Verzorgingsgebied DELTA KABELCOMFORT B.V. *** -Ontwerpbesluit - OPTA, 19 mei 2005 1 1. INLEIDING EN SAMENVATTING 5 1.1. Inleiding 5 1.2. Marktdefinitie, wholesale 5 1.3. Aanmerkelijke marktmacht, wholesale 6 1.4. Verplichtingen, wholesale 6 1.5. Marktdefinitie en aanmerkelijke marktmacht, retail 7 2. JURIDISCH KADER 8 2.1. Inleiding 8 2.2. De Telecommunicatiewet 9 2.3. De Europese regelgeving 12 2.3.1. Richtsnoeren 13 2.3.2. De aanbeveling betreffende relevante producten en dienstenmarkten 13 2.3.3. De ‘Common Position’ van de European Regulators Group inzake verplichtingen 14 2.4. De consultatie 14 2.4.1. De nationale consultatie 14 2.4.2. De Europese consultatie en notificatie 15 3. GEHANTEERDE BENADERING BIJ DE MARKTANALYSES 17 3.1. Inleiding 17 3.2. Bepaling van de relevante markten 17 3.3. De beoordeling van aanmerkelijke marktmacht 21 3.4. Het opleggen van passende verplichtingen 22 4. VERLOOP VAN DE PROCEDURE 27 4.1. Procesbeschrijving 27 4.2. Aard verzamelde gegevens 27 4.3. Afstemming met de NMa 27 5. BEPALING VAN DE RETAILMARKT 28 5.1. Inleiding 28 5.2. Retailproducten in Nederland 28 5.3. Internet Protocol (IP) 30 5.4. Substitutieanalyse 32 5.4.1. Bestaande wholesaleverplichtingen 33 5.4.2. Marktsituatie in afwezigheid van bestaande wholesaleverplichtingen 33 5.4.3. Productgroep 1: Analoge radio en televisie via de kabel 34 5.4.4. Productgroep 2: Radio- en televisiepakketten via de kabel via een systeem van voorwaardelijke toegang 41 5.4.5. Productgroep 3: Analoge radiosignalen via de ether 44 5.4.6.