Calhoun: The NPS Institutional Archive DSpace Repository Theses and Dissertations Thesis and Dissertation Collection 2015-03 Refined orbital architecture for targets of naval interest Konowicz, Andrew Monterey, California: Naval Postgraduate School http://hdl.handle.net/10945/45209 Downloaded from NPS Archive: Calhoun NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS REFINED ORBITAL ARCHITECTURE FOR TARGETS OF NAVAL INTEREST by Andrew Konowicz March 2015 Thesis Advisor: Richard C. Olsen Co-Advisor: Alan D. Scott Approved for public release; distribution is unlimited THIS PAGE INTENTIONALLY LEFT BLANK REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704–0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instruction, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188) Washington, DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED March 2015 Master’s Thesis 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS REFINED ORBITAL ARCHITECTURE FOR TARGETS OF NAVAL INTEREST 6. AUTHOR(S) Andrew Konowicz 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION Naval Postgraduate School REPORT NUMBER Monterey, CA 93943-5000 9. SPONSORING /MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING N/A AGENCY REPORT NUMBER 11. SUPPLEMENTARY NOTES The views expressed in this thesis are those of the author and do not reflect the official policy or position of the Department of Defense or the U.S. Government. IRB Protocol number ____N/A____. 12a. DISTRIBUTION / AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Approved for public release; distribution is unlimited 13. ABSTRACT (maximum 200 words) The objective of this research is to address the feasibility of designing prograde orbits for commercial electro-optical satellites. This study explores prograde orbits (inclined less than 90°) populated by small, inexpensive but proven commercial satellites, like SkySat-1 of SkyBox Imaging Inc. The benefits of using prograde orbits are increased coverage duration and decreased revisit, or gap, times for point targets at most latitudes. Disadvantages include a reduction of high-latitude target coverage (sometimes completely), a more elaborate ground architecture, and the increased expense of populating a constellation of these satellites—to mitigate the laws of orbital mechanics—in order to achieve the desired benefits of prograde inclinations. This thesis considers orbital plane inclinations of 30°, 45°, and 60°; designs a few 24-satellite prograde constellations; and compares the performance of these newly formed constellations to the traditional sun synchronous orbit. As anticipated by the orbital mechanics, the results show that annual coverage can increase up to 6.5 times, average access increases up to 6.94 per day, and revisit time can be reduced to as low as 2.0 hours. In addition, the approximate annual life-cycle cost will likely fall beneath $0.5 billion. 14. SUBJECT TERMS 15. NUMBER OF Space Operations, Prograde Inclination, Constellations, Coverage, Revisit, Daily Access, Commercial PAGES Satellites, Electro-optical 59 16. PRICE CODE 17. SECURITY 18. SECURITY 19. SECURITY 20. LIMITATION OF CLASSIFICATION OF CLASSIFICATION OF THIS CLASSIFICATION OF ABSTRACT REPORT PAGE ABSTRACT Unclassified Unclassified Unclassified UU NSN 7540–01-280-5500 Standard Form 298 (Rev. 2–89) Prescribed by ANSI Std. 239–18 i THIS PAGE INTENTIONALLY LEFT BLANK ii Approved for public release; distribution is unlimited REFINED ORBITAL ARCHITECTURE FOR TARGETS OF NAVAL INTEREST Andrew Konowicz Lieutenant, United States Navy B.S., Boston University, 2006 Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN SPACE SYSTEMS OPERATIONS from the NAVAL POSTGRADUATE SCHOOL March 2015 Author: Andrew Konowicz Approved by: Richard C. Olsen Thesis Advisor Alan D. Scott Co-Advisor Rudy Panholzer Chair, Space Systems Academic Group iii THIS PAGE INTENTIONALLY LEFT BLANK iv ABSTRACT The objective of this research is to address the feasibility of designing prograde orbits for commercial electro-optical satellites. This study explores prograde orbits (inclined less than 90°) populated by small, inexpensive but proven commercial satellites, like SkySat- 1 of SkyBox Imaging Inc. The benefits of using prograde orbits are increased coverage duration and decreased revisit, or gap, times for point targets at most latitudes. Disadvantages include a reduction of high-latitude target coverage (sometimes completely), a more elaborate ground architecture, and the increased expense of populating a constellation of these satellites—to mitigate the laws of orbital mechanics— in order to achieve the desired benefits of prograde inclinations. This thesis considers orbital plane inclinations of 30°, 45°, and 60°; designs a few 24-satellite prograde constellations; and compares the performance of these newly formed constellations to the traditional sun synchronous orbit. As anticipated by the orbital mechanics, the results show that annual coverage can increase up to 6.5 times, average access increases up to 6.94 per day, and revisit time can be reduced to as low as 2.0 hours. In addition, the approximate annual life-cycle cost will likely fall beneath $0.5 billion. v THIS PAGE INTENTIONALLY LEFT BLANK vi TABLE OF CONTENTS I. INTRODUCTION........................................................................................................1 A. STATEMENT OF THE PROBLEM AND OBJECTIVE ...........................1 B. THESIS BOUNDARIES .................................................................................2 II. REFERENCE MATH AND VOCABULARY ..........................................................3 A. ORBITAL TERMS ..........................................................................................3 1. Semimajor Axis for Low Earth Orbit (LEO) ....................................4 2. Inclination and Prograde Orbits ........................................................4 3. RAAN and Orbit Precession ...............................................................5 a. Prograde Orbit Precession Effects ...........................................5 b. Sun Synchronous Orbits (SSO) ................................................9 B. MEANINGFUL METRICS FOR SATELLITE ACCESS ........................10 III. BACKGROUND ........................................................................................................11 A. THESIS FOLLOW-ON .................................................................................11 B. ARGUMENT AGAINST MYTHICAL TACTICAL SATELLITES .......11 C. THE WORK CONTINUED..........................................................................13 D. A NOTE ON OPTIMIZATION ...................................................................13 IV. SINGLE SATELLITE DESIGN AND TESTING ..................................................15 A. MODEL ASSUMPTIONS.............................................................................15 1. Analysis Period ...................................................................................15 2. STK Propagator and Coordinate System ........................................15 3. Eccentricity .........................................................................................16 4. Sun Elevation Angle ...........................................................................16 5. Optical Field of View (FOV) .............................................................16 6. Variables Not Considered .................................................................17 7. Targets of Naval Interest ...................................................................17 B. SINGLE SATELLITE DESIGN RESULTS ...............................................21 1. Performance: One Satellite at Prograde Inclinations.....................22 2. Performance: One Satellite in Sun Synchronous Orbit Inclination ...........................................................................................23 3. Comparisons of Prograde to SSO – One Satellite ...........................24 4. Trends .................................................................................................25 V. CONSTELLATION DESIGN AND TESTING ......................................................27 A. MESHED COMBS.........................................................................................27 B. GENETIC ALGORITHMS ..........................................................................27 C. 24-PLANE WALKER CONSTELLATIONS .............................................28 1. Constellation Design ..........................................................................28 a. Walker......................................................................................28 b. Walker Variation with (t/f/p) ..................................................28 c. “Hourly” Walker .....................................................................29 D. 24-PLANE WALKER DESIGN RESULTS ................................................30