DOCUMENT RESUME ED 162 635 IE 006 582 AUTHOR Davidoff, Martin R. TITLE Using Satellites in the Classrocm: A Guide for Science Educators. INSTITUTION Catcnsville Community Ccll., Md. SPONS AGENCY National Science Foundatior, Washingtcn, D.C. PUB DATE 78 GRANT SED 75-17333 NOTE 234p. AVAILABLE FROM Ms. Julie Forbush, Smithscnian Air 6 Space Museum, Washington, D. C. 20560 (Free, while supply lasts) EDRS PRICE MF-$0.83 HC-$12.71 Plus Postage. DESCRIPTORS *Ccmmunication Satellites; Higher Education; *Radio Technology; Science Activities; *Science Education; Science Experiments; Science Prcjects; *Telecommunication IDENTIFIERS Orbiting Satellite Carrying Amateur Radio; Radio Amateur Satellite Cbrperaticn ABSTRACT The function, design, and ground statics ceguirements of the AMSAT-OSCAR ncn-ccmmercial space satellite system are described, and various experiments designed for direct student participation in space communications are provided in this text primarily written for the science educator. Six chapters include:) (1) an introduction to general satellitecrtit problems and sclutione, (2) a number of trackingmethods_ for ccmputing the positicns of 1 satellites, (3) onboard systems common to most satellites, (4) ai complete descripticn of each of the satellites currently in orbit or planned for the near future, (5) specifics fcr ground stations, and (6) four complete student satellite experiments, 15 detailed prcject outlines, and 19 suggestions for topics and activities. AppendiCes include listings of equipment manufactirers and publishers, as well as a glossary of terms. .(Author/RAO) #31g4g###########*31g#714########*###*######****************7144**714*71444714### * Reproductions supplied by EDRS are the ,best that car be made * * from the original document. * *********************************************************************** USING SATELLITES IN THE CLASSROOM: A GUIDE FOR SCIENCE EDUCATORS U.S. DEPARTMENT OF HEALTH. EDUCATION & WELFARE NATIONAL INSTITUTE OF EDUCATION Martin R. Davidoff, Ph.D. THIS DOCUMENT HAS BEEN REPRO- '. DUCED EXACTLY AS RECEIVED FROM THE PERSON OR ORGANIZATION. ORIGIN- ''ATING IT POINTS OF VIEW OF. JPINIOkS STATED-4:X) NOT NECESSARi'.Y REPRE- SENT OFFICIAL NATIONAL I,1 iTITUTE OF EDUCATION POSITION OR PGL:CY "PERMISSION TO REPRODUCE THIS MATERIAL HAS BEEN GRANTEDBY Martin Davidoff TO THE EDUCATIONAL RESOURCES INFORMATION CENTER (ERIC) AND USERS OF THE ERIC SYSTEM." USING SATELLITES IN THE CLASSROOM: A GUIDE FOR SCIENCE EDUCATORS Martin R. Davidoff, Ph.D. Catonsville Community College Catonsville, Md. 21228 Copyright © Martin Davidoff 1978 Printed in the United States of America. All rights reserved. This book or parts thereof may not be reproduced in any form without permission. The materials contained herein are based in part upon research supported by the National Science Foundation Uhder. Grant Na:-SED 75-17333.-- Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author and do not necessarily reflect the views of the National Science Foundation or Catonsville Community College. Published by Catonsville Community College. First Edition: 1978 ii Tha book £6 dedicated to the vaanteera mound .the wontd who hetped the OSCAR ptogitam ity. ACKNOWLEDGMENTS This text was made possible by the scientific, financial, and moral\ support of a number of individuals and organizations. The RADIO-AMATEUR-SATELLITE-CORPORATION (AMSAT) built the spacecraft upon which this text is based. Special thanks are due to Mr. Jan King and Dr. Perry Klein for constructively reviewing several drafts of the manuscript.\ The NATIONAL SCIENCE FOUNDATION SCIENCE EDUCATION DIRECTORATE provided funds so that the practical aspects of using satellites in a classroom could be tested. This book was written, produced, and distributed to college level educators as part of project SED 75-17333. The advisory,committee for this project consisted of: Dr. Pier Bargellini, COMSAT Laboratories; Dr. Sajjad Durrani, NASA; Dr. Allen Katz, Trenton State College, NJ; Dr. Perry Klein, AMSAT; Mr. Donald LaSalle, Talcott Mtn. Science Center, Conn.; Mr. William Tynan, Hopkins Applied Physics Laboratory. Special recognition is-also due to the assistance provided by: Catonsville Community College, Md.; The American Radio Relay League tatellite Educational Programs Office; 0 The Smithsonian Air and Space Museum; The National Aeronautida and Space Administration Educational Programs Office. iii CONTENTS Page COMER ORS AND CONSTANTS vi CRAM I. EA IITES: ORBITS AND TRACKING 1-1 1,1 round 1-2 1.2 0 lite Path in Space 1-5 1.3 Sub 'atellite Path on Earth (Ground Track) 1.4 Azimuth, Elevation, Coverage 1-17 1.5 1:%1Aptical Orbits: Selected Topics 1-20 References 1-25 II. TRACKXF AMSAT-OSCAR SATELLITES 2-1 2.1 iLlcoduction 2-1 2.2 Method I: Selected Cities 2-11 2.3 Method II: North Pole Projection Map 2-12 2.4 Method III: Mercator Map 2-18 2.5 Method IV: Azimuthal Equidistant Projection Map . 2-18 2.6 Method V: Globe 2-21 2:7 Method VI: Computer 2 -22, 2.8 Elliptic Orbits and AMSAT Phase III Satellites 223 2,9 Comments 2-29 References 2-29 III. SATELLITE SYSTEMS 3-1 3.1 Satellite. Systems: Overview' 3-1 3.2 Communications, Mission, and Engineering Subsystems . 3-4 Beacons: Function 3-4 Beacons: Design 3-8 Command Links 3-9 Transponders: Function 3-9 Transponders: Design 3-10 Telemetry Systems 3-13 3.3 Structural, Attitude-Control, Propulsion, and Energy-Supply Subsystems 3-15 Structural Subsystem 3-15 Attitude-Control Subsystem 3-15 , Propulsion Subsystem 3-18 Energy-Supply Subsystem 3-19 References 3-22 IV., SATELLITE DESCRIPTIONS 4-1 AMSAT-OSCAR 7. 4-4 AMSAT-OSCAR 8 4-18 -AMSAT-Phase-III-A 4-27. Sciviet RS-1 4-33 Page V. GROUND STATION EQUIPMENT .5-1 5.1 Basic 29 MHz Ground Station ....... , . 5-2 5.2 Receivers .5-3 5.3 .Antenna Basics 5-7 -5:4- Practical Ground Statioh Antennas 5-13 5.5 Station Assembly: General 5-24 5.6 Transmitting Considerations 5-29 References 5-33 VI. EDUCATIONAL EXPERIMENTS AND ACTIVITIES 6-1 6.1 Developing Tracking Data 6-1 Experiment SE 1 :Satellite Tracking ..... 6-2 6.2 Derivation of Tracking Equations-----__--- . 6-5.. Project SP 1: Elevation Angle and Slant Range . 6-6 Project SP 2: Motion in Orbital Plane 6-7 Project. SP 3: Ground Tn.ck 6-8 6.3 Doppler Effect. 6-11 Experiment SE 2: Doppler Effect' 6-12 Project SP 4: Accurate Frequency Measurement 6-19 Project SP 5:-Theoretical Doppler Curves 6-20 Project SP 6: Anomolous Doppler 6-22 6.4 Telemetry Reduction .6-23 Experiment SE 3: Energy Flow in Space 6-24 Experiment SE 4 :Satellite Orientation ..... 6-32 Project SP 7: Solar Cells and Power Budget 6-40 Project SP 8: Measuring the Solar Constant . 6-42 Project SP 9: Determining the Earth's Albedo 6-44 6.5 Propagation 6-46 -Project SP 10: Faraday Rotation 6-46 Project SP 11: Auroral Effects 6-48 Project SP 12: Antipodal Reception 6-48 Project SP 13: Extended Range Reception 6-49 6.6 Satellite System Design 6-51 Project SP 14: Selecting a Satellite Antenna 6 -52 6.7 Satellite Ranging 6-57 Project SP 15: Satellite Ranging 6-57 6.8 Miscellaneous Activities 6-61 SM 1 - SM 20 ........... 6-61 References 6-69 APPENDIX A: Addresses of Equipment Manufacturers, Publishers, Etc. A-1 APPENDIX B: Short Glossary of Terms and Abbreviations A-2 CONVERSION FACTORS -4 Length 1.000 m 3.281 feet = 6.214 x 10 mile (statute) -4 5.396 x 10 mile (nautical) 1.000° of arc at surface. of.earth = 111.2 km 2 Mass 1.000 kg 4= 6.852 x 10 slugs Force 1.000 N = .2248 pounds 1.000 kg (force)-4-4, 2.205 pounds (at surface of earth) CONSTANTS 6 R Mean radius of earth: 6.371 x 10m (3,959st. mile) 6 R Equatorial radius of earth: 6.378 x 10m (3,963 st.mile) eq 24 23 M Mass of earth: 5.98 x 10 kg (4.10 x 10 slugs) G Universal Gravitational Constant: 3 3 ft 6.67 x 10-j". m ; (3.44 x108 2 2 kg-s 3 14 m 16 ft3 GM 3.986 x 10 ( 1.408 x 10 ) S 2 P. Solar constant: 1.38 kwatt/m Cr Stefan-Boltzmann constant: joules 5.67 x10842 K m s Abbreviations Kelvin 'kg = kilogram = meter N = Newton . s = second 7 vi PREFACE TO THE SCIENCE EDUCATOR: The primary objectives of this book are: 1. to show science educators how space satellitesican be used to a) present normal course contentI-ii a new'and intrinsically interesting format and/or b) introduce students to space science; ? to provide educators with complete information needed to assemble a satellite ground station suitable for "live" classroom demonstrations and "hands-on" "real-time" student laboratory exercises; 3. to provide science educators with background material on satellite systems. This text treats the use of a new and exciting tool for science instruction -- multi-million dollar satellites which-are directly available to faculty and students without charge for use in the classroom. Note that this text is not concerned with instructional TV or radio via satellite. vii8 INTRODUCTION The major practical development of the space age has been earth satellites. In the brief period since the launch of Sputnik I (Oct. 4, 1957) space technology has evolved to the point where today, the majority of inter- national telecommunications is handled by satellite [1]. Satellites are also used.to provide daily datalor weather forecasting and environmental monitoring as well as for natural resource assessment, navigation, and instructional TV broadcasting. Satellite parking problems have already developed in some regions of space due_tohe increasing number of satellites' in certain desirable orbits [2]. While.a few science educators pioneered in using early satellites in the classroom, educational applications of satellites never became widespread. Perhaps the main. reason for this is that educational appliCations havealways been a distinctly secondary consideration in the development of most satel- lites.