DOCSLIB.ORG

Orbital Aggregation & Space Infrastructure Systems (OASIS)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Revolutionary Aerospace Systems Concepts Orbital Aggregation & Space Infrastructure Systems (OASIS) Preliminary Architecture and Operations Analysis FY2001 Final Report June 10, 2002 This page intentionally left blank. Foreword Just as the early American settlers pushed west beyond the original thirteen colonies, the world today is on the verge of expanding the realm of humanity beyond its terrestrial bounds. The next great frontier lies ahead in low-Earth orbit and beyond. Commercialization of space has recently been mostly limited to communications and remote sensing applications, but materials processing, manufacturing, tourism and servicing opportunities will undoubtedly increase during the first part of the new millennium. Discoveries hinting at the existence of water on Mars and Europa offer additional motivation for establishing a space-based infrastructure that supports extended human exploration of the solar system. If this space-based infrastructure were also utilized to stimulate and support space commercialization, permanent human occupation of low-Earth orbit and beyond could be achieved sooner and more cost effectively. The purpose of this study is to identify synergistic opportunities and concepts among human exploration initiatives and space commercialization activities while taking into account technology assumptions and mission viability in an Orbital Aggregation & Space Infrastructure Systems (OASIS) framework. OASIS is a set of concepts that provide a common infrastructure for enabling a large class of space missions. The concepts include communication, navigation and power systems, propellant modules, tank farms, habitats, and transfer systems using several propulsion technologies. OASIS features in-space aggregation of systems and resources in support of mission objectives. The concepts feature a high level of reusability and are supported by inexpensive launch of propellant and logistics payloads. The anticipated benefits of the synergistic utilization of space infrastructure are reduced mission costs and increased mission flexibility for future space exploration and commercialization initiatives. i This page intentionally left blank. ii Executive Summary The study was performed under the Revolutionary Aerospace Systems Concepts (RASC) activity led by the NASA Langley Research Center (LaRC). LaRC was chartered by the NASA Administrator to be the lead Center for evaluating revolutionary aerospace systems concepts and architectures to identify new mission approaches and the associated technologies that enable these missions to be implemented. Mission There are many challenges confronting humankind’s exploration of space, and many engineering problems that must be solved in order to provide safe, affordable and efficient in-space transportation of both personnel and equipment. These challenges directly impact the commercialization of space, with cost being the single largest obstacle. One method of reducing cost is to develop reusable transportation systems— both Earth-to-orbit systems and in-space infrastructure. Without reusable systems, sustained exploration or large-scale development beyond low-Earth-orbit (LEO) appears to be economically non-viable. However, reusable in-space transportation systems must be capable of both high fuel efficiency and “high utilization of capacity,” or economic costs will remain unacceptably high. Fixed infrastructures have been suggested as one approach to solving this challenge; for example, rotating tether approaches. However, these systems tend to suffer from high initial costs or unacceptable operational constraints. Another significant challenge is minimizing the in-space travel time for crewed missions. The risks associated with human missions can be significantly reduced by decreasing the time that the crew is in transit. Besides nuclear thermal propulsion systems and the inherent public concerns that accompany the use of these systems near the Earth, the propulsive system that provides a reasonably high thrust and short transit time is one that uses chemical propellants. One significant drawback to chemical systems is the relatively low specific impulse (Isp) requiring large propellant quantities to provide the velocity changes necessary to complete a mission. Solar electric propulsion (SEP) systems can provide high fuel efficiency but only at the cost of low thrust and transit times that are not compatible with crewed missions. An innovative concept that integrates the best features of both chemical and solar electric propulsive systems is proposed in this report. This concept appears to hold the promise of solving the issues associated with other approaches and may provide a new family of capabilities for future exploration and commercial development of near-Earth space and beyond. Study Summary An architecture composed of common in-space transportation elements was derived to support both human exploration and commercial applications in the Earth-moon neighborhood. Mission concepts utilizing this architecture are predicated on the availability of a low-cost launch vehicle for delivery of propellant and re-supply logistics. Infrastructure costs would be shared by Industry, NASA and other users. iii The Orbital Aggregation & Space Infrastructure Systems (OASIS) architecture minimizes point designs of elements in support of specific space mission objectives and maximizes modularity, reusability and commonality of elements across many missions, enterprises and organizations. A reusable Hybrid Propellant Module (HPM) that combines both chemical and electrical propellant in conjunction with modular orbital transfer/engine stages was targeted as the core OASIS element. The HPM provides chemical propellant for time critical transfers and provides electrical propellant for pre- positioning or return of the HPM for refueling and reuse. The HPM incorporates zero- boil off technology to maintain its cryogenic propellant load for long periods of time. The Chemical Transfer Module (CTM) is an OASIS element that serves as a high energy injection stage when attached to an HPM. The CTM also functions independently of the HPM as an autonomous orbital maneuvering vehicle for proximity operations such as payload ferrying, refueling and servicing. The Solar Electric Propulsion (SEP) Stage serves as a low thrust transfer stage when attached to an HPM for pre-positioning large/massive elements or for the slow return of elements for refurbishing and refueling. The Crew Transfer Vehicle (CTV) is used to transfer crew in a shirt sleeve environment from LEO to the L1 Earth–Moon Lagrange point and back as well as to the International Space Station (ISS) and any other crewed infrastructure elements. Parametric launch cost analysis of the OASIS architecture supporting NASA Lunar Gateway missions has demonstrated the potential cost advantage of this reusable architecture over an architecture with few reusable elements. When using today’s Space Shuttle for initial launch of the OASIS elements, the cross-over point where the OASIS architecture becomes more cost effective than non-reusable architectures is at approximately 8 lunar missions (4 to 4 ½ years assuming lunar missions every six months). If a high capacity, relatively low cost Delta IV-H is used for initial launch of OASIS elements, this cross-over point occurs at lunar mission #3 (1 ½ years). Analysis of commercial scenarios utilizing the HPM and CTM for satellite delivery and servicing show that a launch cost of $1,000/kg for propellant to re-supply the space-based elements is required for economic viability given a range of assumptions for element development costs and frequency of use. In these scenarios, Industry will leverage government investment in OASIS infrastructure development. Technology Identification A major assumption in support of the OASIS architecture is the availability of technologies to enable the routine and inexpensive launch of propellant to LEO. These technologies are being identified through NASA’s Space Launch Initiative (SLI). Many advanced technologies also are necessary to make an OASIS architecture a reality, including technologies specifically applicable to the HPM, CTM, CTV, and SEP Stage. With the proper funding levels, many of the technologies could be available within the next 15 years. Accelerated funding levels could make this timeline significantly shorter. The following is a brief description of some of the key technologies needed for the development of an OASIS architecture: iv • Zero boil-off cryogenic propellant storage system providing up to 10 years of storage without boil-off • Extremely lightweight, integrated primary structure and meteoroid and orbital debris shield incorporating non-metallic hybrids to maximize radiation protection • High efficiency power systems such as advanced triple junction crystalline solar cells providing at least 250 W/kg (array-level specific power) and 40% efficiency, along with improved radiation tolerance • Long-term autonomous spacecraft operations including rendezvous and docking, propellant transfer, deep-space navigation and communications, and vehicle health monitoring (miniaturized monitoring systems) • Reliable on-orbit cryogenic fluid transfer with minimal leakage using fluid transfer interfaces capable of multiple autonomous connections and disconnects • Lightweight composite cryogenic propellant storage tanks highly resistant to propellant leakage • Advanced materials such as graphitic foams and syntactic metal foams • Long-life chemical
Recommended publications
  • The Annual Compendium of Commercial Space Transportation: 2017

    The Annual Compendium of Commercial Space Transportation: 2017

    Federal Aviation Administration The Annual Compendium of Commercial Space Transportation: 2017 January 2017 Annual Compendium of Commercial Space Transportation: 2017 i Contents About the FAA Office of Commercial Space Transportation The Federal Aviation Administration’s Office of Commercial Space Transportation (FAA AST) licenses and regulates U.S. commercial space launch and reentry activity, as well as the operation of non-federal launch and reentry sites, as authorized by Executive Order 12465 and Title 51 United States Code, Subtitle V, Chapter 509 (formerly the Commercial Space Launch Act). FAA AST’s mission is to ensure public health and safety and the safety of property while protecting the national security and foreign policy interests of the United States during commercial launch and reentry operations. In addition, FAA AST is directed to encourage, facilitate, and promote commercial space launches and reentries. Additional information concerning commercial space transportation can be found on FAA AST’s website: http://www.faa.gov/go/ast Cover art: Phil Smith, The Tauri Group (2017) Publication produced for FAA AST by The Tauri Group under contract. NOTICE Use of trade names or names of manufacturers in this document does not constitute an official endorsement of such products or manufacturers, either expressed or implied, by the Federal Aviation Administration. ii Annual Compendium of Commercial Space Transportation: 2017 GENERAL CONTENTS Executive Summary 1 Introduction 5 Launch Vehicles 9 Launch and Reentry Sites 21 Payloads 35 2016 Launch Events 39 2017 Annual Commercial Space Transportation Forecast 45 Space Transportation Law and Policy 83 Appendices 89 Orbital Launch Vehicle Fact Sheets 100 iii Contents DETAILED CONTENTS EXECUTIVE SUMMARY .
  • ON FORMING the MOON in GEOCENTRIC ORBIT Herbert, F., Et Al

    ON FORMING the MOON in GEOCENTRIC ORBIT Herbert, F., Et Al

    ON FORMING ME MOON IN GEOCENTRIC ORBIT; DYNAMICAL EVOLUTION OF A CIRCUMTERRESTRIAL PLANETESIMAL SWARM; Floyd Herbert, University of Arizona, Tucson, and D.R. Davis and S.J. Weidenschilling, Planetary Science Institute, Tucson, AZ. The wclassicalv theories of lunar origin all have major difficulties that have prevented any of them from beinq generally accepted: the capture hypo- thesis is quite improbable, while the fission hypothesis suffers a larqe anqular momentum problem. New theories have, of course, sprouted to replace these -- tidal disruption/capture, accretion in geocentric orbit, and the qiant impact hypothesis. At a recent conference on the oriqin of the moon (October, 1984, Kona, HI), the qiant impact hypothesis, which holds that the moon formed as the result of a large (Mercury-to-Mars-sized) planetesimal impactinq the proto-Earth, emerqed as the current favored hypothesis, with co-formation in geocentric orbit a possible alternative. The latter model, which suqgests that the moon formed from planetesimals captured from helio- centric orbit and forminq a circumterrestrial disk, was criticized also as suffering an angular momentum deficit, based on our preliminary results (1). We present here additional results of studies of anqular momen-tum input to a circumterrestrial swarm by planetesimals arriving from heliocentric orbits. Such a target swarm could have formed initially by collisions among heliocentric planetesimals passing within Earth's sphere of influence. Such collisions have a siqnificant probability (tens of $1 of yieldinq capture into qeocentric orbit (2). We assume that the swarm is evolvinq due to collisions with the heliocentric planetesimal population as they pass close to the Earth.
  • Successful Demonstration for Upper Stage Controlled Re-Entry Experiment by H-IIB Launch Vehicle

    Successful Demonstration for Upper Stage Controlled Re-Entry Experiment by H-IIB Launch Vehicle

    Mitsubishi Heavy Industries Technical Review Vol. 48 No. 4 (December 2011) 11 Successful Demonstration for Upper Stage Controlled Re-entry Experiment by H-IIB Launch Vehicle KAZUO TAKASE*1 MASANORI TSUBOI*2 SHIGERU MORI*3 KIYOSHI KOBAYASHI*3 The space debris created by launch vehicles after orbital injections can be hazardous. A piece of debris can collide with artificial satellites or cause a casualty when it falls back to earth, which is an ongoing problem among countries that utilize outer space. This paper reports on a Japanese controlled re-entry disposal method that brings the upper stage of a launch vehicle down in a safe ocean area after the mission has been completed. The method was successfully demonstrated on the H-IIB launch vehicle during Flight No. 2, and provides a means of reducing the amount of space debris and the risk of ground casualty. |1. Introduction The H-IIB launch vehicle was jointly developed by the Japan Aerospace Exploration Agency (JAXA) and Mitsubishi Heavy Industries, Ltd., to launch the Kounotori (‘Stork’) H-II Transfer Vehicle (HTV), which carries supply goods to the International Space Station (ISS). The H-IIB launch vehicle has the largest launch capability of the H-IIA launch vehicle family: it can inject a 16.5-ton HTV into a low earth orbit (ISS transfer orbit). Figure 1 shows an overview of the H-IIB launch vehicle. Figure 1 Overview of the H-IIB launch vehicle The changes introduced in the H-IIB launch vehicle are as follows: ・ Enhanced first stage relative to the H-IIA: tank diameter extension, cluster system for two main engines, and four solid rocket boosters (SRB-A) ・ Reinforced upper stage (second stage) relative to the H-IIA to launch the HTV ・ 5S-H fairing (newly developed to launch the HTV) H-IIB Test Flight No.
  • Deep Space Network Ission Suppo

    Deep Space Network Ission Suppo

    870-14, Rev. AF Deep Space Network ission Suppo Jet Propulsion Laboratory California institute of Technology JPL 0-0787,Rev. AF 870-14, Rev. AF October 1991 Deep Space Network ission Support Re uirements Reviewed by: L.M. McKinley TDA Mission Support Off ice Approved by: R.J. Amorose Manager, TDA Mission Support Jet Propulsion Laboratory California Institute of Technology JPL 0-0787, Rev. AF 870.14. Rev . AF CONTENTS INTRODUCTION............................................................ 1-1 A . PURPOSE AND SCOPE ................................................. 1-1 B . REVISION AND CONTROL .............................................. 1-1 C . ORGANIZATION OF DOCUMENT 870-14 ................................... 1-1 D . ABBREVIATIONS ..................................................... 1-1 ASTRO-D ................................................................. 2-1 BROADCASTING SATELLITE-3A AND -3B (BS-3A AND -3B) ....................... 3-1 CRAF/CASSINI (c/c)...................................................... 4-1 COSMIC BACKGROUND EXPLORER (COBE)....................................... 5-1 DYNAMICS EXPLORER-1 (DE-1).............................................. 6-1 EARTH RADIATION BUDGET SATELLITE (ERBS)................................. 7-1 ENGINEERING TEST SATELLITE-VI (ETS-VI).................................. 8-1 EUROPEAN TELECOMMUNICATIONS SATELLITE I1 (EUTELSAT 11) .................. 9-1 EXTREME ULTRAVIOLET EXPLORER (EWE)..................................... 10-1 FRENCH DIRECT TV BROADCAST SATELLITE (TDF-1 AND -2) ....................
  • Orbital Mechanics Joe Spier, K6WAO – AMSAT Director for Education ARRL 100Th Centennial Educational Forum 1 History

    Orbital Mechanics Joe Spier, K6WAO – AMSAT Director for Education ARRL 100Th Centennial Educational Forum 1 History

    Orbital Mechanics Joe Spier, K6WAO – AMSAT Director for Education ARRL 100th Centennial Educational Forum 1 History Astrology » Pseudoscience based on several systems of divination based on the premise that there is a relationship between astronomical phenomena and events in the human world. » Many cultures have attached importance to astronomical events, and the Indians, Chinese, and Mayans developed elaborate systems for predicting terrestrial events from celestial observations. » In the West, astrology most often consists of a system of horoscopes purporting to explain aspects of a person's personality and predict future events in their life based on the positions of the sun, moon, and other celestial objects at the time of their birth. » The majority of professional astrologers rely on such systems. 2 History Astronomy » Astronomy is a natural science which is the study of celestial objects (such as stars, galaxies, planets, moons, and nebulae), the physics, chemistry, and evolution of such objects, and phenomena that originate outside the atmosphere of Earth, including supernovae explosions, gamma ray bursts, and cosmic microwave background radiation. » Astronomy is one of the oldest sciences. » Prehistoric cultures have left astronomical artifacts such as the Egyptian monuments and Nubian monuments, and early civilizations such as the Babylonians, Greeks, Chinese, Indians, Iranians and Maya performed methodical observations of the night sky. » The invention of the telescope was required before astronomy was able to develop into a modern science. » Historically, astronomy has included disciplines as diverse as astrometry, celestial navigation, observational astronomy and the making of calendars, but professional astronomy is nowadays often considered to be synonymous with astrophysics.
  • Experimental Analysis of Low Earth Orbit Satellites Due to Atmospheric Perturbations

    Experimental Analysis of Low Earth Orbit Satellites Due to Atmospheric Perturbations

    IAETSD JOURNAL FOR ADVANCED RESEARCH IN APPLIED SCIENCES ISSN NO: 2394-8442 Experimental Analysis of Low Earth Orbit Satellites due to Atmospheric Perturbations Aman Saluja#1, Manish Bansal#2, M Raja#3, Mohd Maaz#4 #Aerospace Department, University of Petroleum and Energy Studies, Dehradun [email protected], [email protected], [email protected], [email protected] Abstract— A satellite is expected to move in the orbit until its life is over. This would have been true if the earth was a true sphere and gravity was the only force acting on the satellite. However, a satellite is deviated from its normal path due to several forces. This deviation is termed as orbital perturbation. The perturbation can be generated due to many known and unknown sources such as Sun and Moon, Solar pressure, etc. This paper discusses the study of perturbation of a Low Earth satellite orbit due to the presence of aerodynamic drag. Numerical method (Runge - Kutta fourth order) is used to solve the Cowell’s equation of perturbation, which consists of ordinary differential equation. Keywords— Low Earth Orbit (LEO), Cowell’s method, atmospheric perturbation, orbital elements, numerical method (RK4) I. INTRODUCTION Satellite is a space vehicle which is used for different purposes like communication, weather forecasting, surveillance, etc. so, for each purpose the design, working and the altitude the satellite to be placed, is different for different types of satellites which depends on the purpose of the satellite. A perturbation is actually a deviation from real or expected motion. It can be small or large depending upon the type of perturbation and the type of orbit the satellite is in.
  • Order-Of-Magnitude Estimation Earth Orbiter (Level 1)

    Order-Of-Magnitude Estimation Earth Orbiter (Level 1)

    Order-of-Magnitude Estimation Earth Orbiter (Level 1) The Question A geostationary satellite orbits the Earth once each day. About how fast is it traveling in miles per hour? Background Geostationary satellites are designed to remain above the same point on the Earth’s surface, orbiting the Earth exactly once per day. It is possible to expand this question to an expert- level question by determining the exact distance to a satellite with an orbital period of 24 hours. Or, as an alternative starting point, most people can be guided to estimate that a satellite orbits at “a few times the Earth’s radius”. Guiding Questions Here are some things you may need to consider: Always have an initial guess at the answer without any OoM estimation! • Newton’s Law of Gravity is F = GMm/r2 for a body of mass (M) exerting a gravi- • tational force on a second mass m at a distance r. G is the Gravitational Constant. Newton’s Second Law in angular form is F = ma = mrω2 = mr(4π2)/T 2 for a mass • m moving in a circle of radius r that takes a period T to orbit once. How can we estimate the distance to geostationary orbit? • How can we estimate the circumference of geostationary orbit? • How are speed and distance related to velocity? • The Solution To determine the distance r to geostationary orbit (from the center of the Earth), equate Newton’s Second Law and Newton’s Law of Gravity 1 2 GMm mr(4π ) 3 GM F = = r = T 2 (1) r2 T 2 ⇒ r 4π2 remembering that the time for one orbit of a geostationary satellite is 24 hours or 24 60 60 s, which is about (100/4) 36 100 105 and that π2 10: × × × × ∼ ∼ −11 24 13 3 (6.7 10 )(6 10 ) 3 (40 10 ) r = × × (105)2 × 1010 r 40 ∼ r 40 (2) 3 3 3 √1023 3 1021(100) √100√1021 4.5 107 m ∼ ∼ p ∼ ∼ × Thus we have calculated that geocentric orbit is 45,000km or 25,000 miles.
  • Magnetic Attitude Control of Microsatellites in Geocentric Orbits

    Magnetic Attitude Control of Microsatellites in Geocentric Orbits

    UNIVERSITY OF TORONTO Magnetic Attitude Control of Microsatellites In Geocentric Orbits by Jiten R Dutia Athesissubmittedinpartialfulfillmentforthe degree of Master of Applied Science in the Faculty of Applied Science and Engineering University of Toronto Institute for Aerospace Studies c Copyright by Jiten R Dutia 2013 ! UNIVERSITY OF TORONTO Abstract Faculty of Applied Science and Engineering University of Toronto Institute for Aerospace Studies Master of Applied Science by Jiten R Dutia Attitude control of spacecraft in low Earth orbits can be achieved by exploiting the torques generated by the geomagnetic field. Recent research has demonstrated that attitude stability of a spacecraft is possible using a linear combination of Euler parameters and angular velocity feedback. The research carried out in this thesis implements a hybrid scheme consisting of magnetic control using on-board dipole moments and a three-axis actuation scheme such as reaction wheels and thrusters. A stability analysis is formulated and analyzed using Floquet and Lyapunov stability theorems. ii If we knew what it was we were doing, it would not be called research, would it? Albert Einstein iii Dedicated to my parents and my amazing little sister iv Contents Abstract i List of Tables vii List of Figures viii 1 Introduction 1 1.1 Literature Review .............................. 2 1.2 Approach and Results ........................... 4 1.3 Outline of Thesis .............................. 4 2 Earth’s Magnetic Field 6 2.1 Origins of the Earth’s magnetic field ................... 6 2.2 Effects of Earth’s magnetic field on Spacecraft .............. 10 2.3 Coordinate Systems ............................. 10 2.4 Magnetic Field Models ........................... 12 2.4.1 International Geomagnetic Reference Field ...........
  • 2013 Commercial Space Transportation Forecasts

    2013 Commercial Space Transportation Forecasts

    Federal Aviation Administration 2013 Commercial Space Transportation Forecasts May 2013 FAA Commercial Space Transportation (AST) and the Commercial Space Transportation Advisory Committee (COMSTAC) • i • 2013 Commercial Space Transportation Forecasts About the FAA Office of Commercial Space Transportation The Federal Aviation Administration’s Office of Commercial Space Transportation (FAA AST) licenses and regulates U.S. commercial space launch and reentry activity, as well as the operation of non-federal launch and reentry sites, as authorized by Executive Order 12465 and Title 51 United States Code, Subtitle V, Chapter 509 (formerly the Commercial Space Launch Act). FAA AST’s mission is to ensure public health and safety and the safety of property while protecting the national security and foreign policy interests of the United States during commercial launch and reentry operations. In addition, FAA AST is directed to encourage, facilitate, and promote commercial space launches and reentries. Additional information concerning commercial space transportation can be found on FAA AST’s website: http://www.faa.gov/go/ast Cover: The Orbital Sciences Corporation’s Antares rocket is seen as it launches from Pad-0A of the Mid-Atlantic Regional Spaceport at the NASA Wallops Flight Facility in Virginia, Sunday, April 21, 2013. Image Credit: NASA/Bill Ingalls NOTICE Use of trade names or names of manufacturers in this document does not constitute an official endorsement of such products or manufacturers, either expressed or implied, by the Federal Aviation Administration. • i • Federal Aviation Administration’s Office of Commercial Space Transportation Table of Contents EXECUTIVE SUMMARY . 1 COMSTAC 2013 COMMERCIAL GEOSYNCHRONOUS ORBIT LAUNCH DEMAND FORECAST .
  • Planet Imagery Product Specifications

    Planet Imagery Product Specifications

    PLANET IMAGERY PRODUCT SPECIFICATIONS [email protected] | PLANET.COM LAST UPDATED JANUARY 2018 TABLE OF CONTENTS LIST OF FIGURES _______________________________________________________________________________________ 3 LIST OF TABLES ________________________________________________________________________________________ 4 GLOSSARY ____________________________________________________________________________________________ 5 1. OVERVIEW OF DOCUMENT _____________________________________________________________________________ 7 1.1 Company Overview _________________________________________________________________________________ 7 1.2 Data Product Overview ______________________________________________________________________________ 7 2. SATELLITE CONSTELLATION AND SENSOR OVERVIEW _____________________________________________________ 8 2.1 PlanetScope Satellite Constellation and Sensor Characteristics ______________________________________________ 8 2.2 RapidEye Satellite Constellation and Sensor Characteristics ________________________________________________ 8 2.3 SkySat Satellite Constellation and Sensor Characteristics ___________________________________________________ 9 3. PLANETSCOPE IMAGERY PRODUCTS ____________________________________________________________________ 10 3.1 PlanetScope Basic Scene Product Specification _________________________________________________________ 10 3.2 PlanetScope Ortho Scenes Product Specification _________________________________________________________ 11 3.2.1 PlanetScope Visual Ortho Scene Product
  • Earth-Orbiting Satellites Apogee and Perigee Heights

    Earth-Orbiting Satellites Apogee and Perigee Heights

    UNIVERSITY OF ANBAR ADVANCED COMMUNICATIONS SYSTEMS FOR 4th CLASS STUDENTS COLLEGE OF ENGINEERING by: Dr. Naser Al-Falahy ELECTRICAL ENGINEERING WEEK 2 Earth-Orbiting Satellites As mentioned previously, Kepler’s laws apply in general to satellite motion around a primary body. For the particular case of earth-orbiting satellites, certain terms are used to describe the position of the orbit with respect to the earth. Sub satellite path. This is the path traced out on the earth’s surface directly below the satellite. Apogee is the point farthest from earth. Perigee is the point of closest approach to earth. Apogee and Perigee Heights Although not specified as orbital elements, the apogee height and perigee height are often required. The length of the radius vectors at apogee and perigee can be obtained from the geometry of the ellipse: Example: Calculate the apogee and perigee heights for the following orbital parameters: Mean earth radius of R= 6371 km, e =0.0011501 and a =7192.335 km. Solution: Using Eqs. above: ra =7192.335(1 + 0.0011501) = 7200.607km rp =7192.335(1 - 0.0011501) = 7184.063 km The corresponding heights are: 7 UNIVERSITY OF ANBAR ADVANCED COMMUNICATIONS SYSTEMS FOR 4th CLASS STUDENTS COLLEGE OF ENGINEERING by: Dr. Naser Al-Falahy ELECTRICAL ENGINEERING FREQUENTLY USED ORBITS Geostationary Orbits (GEO) To an observer on the earth, a satellite in a geostationary orbit appears motionless, in a fixed position in the sky. This is because it revolves around the earth at the earth's own angular velocity (360 degrees every 24 hours, in an equatorial orbit).
  • Satellites & Its Applications

    Satellites & Its Applications

    Satellites & its Applications Prepared By: Sai Ganesh P Niranjana Prashant What is a Satellite? A satellite is an object in space that orbits or circles around a bigger object. There are two kinds of satellites: natural (such as the moon orbiting the Earth) or artificial (such as the International Space Station orbiting the Earth). Q1. Which planet has the most number of natural satellites? Examples: Pic Courtesy: Wikipedia Pic Courtesy: Wikipedia 1. Aryabhata 2. Corona Pic Courtesy: Wikipedia 3. International Space Station (ISS) Fun Fact 1: There are about 2,666 satellites active as of April 1, 2020 1st artificial satellite SPUTNIK 1 Fun Fact 2: Sputnik 1 was just about the size of a beach ball. Idea of Satellite ! When the velocity is less than both orbital and escape velocity When the velocity is equal to orbital velocity but is still less than escape velocity When the velocity is greater than both orbital and escape velocity classifications Satellites •Communications Satellite •Remote Sensing Satellite •Navigation Satellite •Geocentric Orbit type satellites - LEO, MEO, HEO •Global Positioning System (GPS) Fun Fact 3: There are 2 satellites in •Geostationary Satellites (GEOs) orbit around the earth chasing each other. •Drone Satellite NASA has them tracking gravitational •Ground Satellite anomalies. NASA nicknamed them Tom •Polar Satellite & Jerry. •Nano Satellites, CubeSats and SmallSats Satellites of all kinds: Activity 1: Draw a funny comic strip or dialogues, explaining what your interaction with a alien would be like. Pic Courtesy: Wikipedia Pic Courtesy: Illinoiscience Pic Courtesy: Wikipedia Pic Courtesy: Wikipedia Orbits ? An orbit is a regular, repeating path that one object in space takes around another one.