NASA-CR-I.197211 NASw-4435 CONCEPTUAL DESIGN OF AN ORBITAL DEBRIS DEFENSE SYSTEM Jd ,c._ West Virginia University -_ ,. , _ iI Department of Mechanical and Aerospace Engineering /j/ / Morgantown, West Virginia Dr. Timothy L. Norman, Asst. Prof Mr. David E Gaskin, NASA/USRA Grad TA Mr. Erik Bedillion Mr. Brian Henry Mr. Jeff Rigglemen Mr. Gary Blevins Ms. Kelly James Mr. Jeff Robinson Mr. Brian Bohs Ms. Kerri Knots Mr. Enoch Ross Mr. David Bragg Ms. Stephanie Mayor Ms. Jeannette Simmons Mr. Christopher Brown Mr. Scott Messick Mr. Taylor Strack Mr. Jose Casanova Ms. Lori Minick Mr. Tsuyoshi Kurosawa Mr. David Cribbs Mr. David Podnar Ms. Amy Yates Mr. Richard Demko Mr. Tom Rankin ,Z3 _0 ,-4 o, • °, °°• I ,-- ,,0 • ° O" _ 0 CO .'..° z_ u.J k*.. o• U.J _" .=.LJ_ _Z OJ LU Z A C3v_ ! :I1 _. I ,_ e,./ 2"U._ ACKNOWLEDGEMENTS The MAE 236 design class would like to thank the following persons for their important contributions. Their help was vital to the completion of the design. I. NASA- George C. Marshall Space Flight Center A. Program Development Office - Charles Darwin (Director) 1. Preliminary Design Office Frank Swalley Deputy Director WVU/MSFC Center Mentor a. System Engineering Division Bill Shelton Chief Dianne Moe Secretary 1. Structural & Thermal Analysis Branch Bob Porter Chief 2. All employees of Program Development B. Marshall Scientific Library C. Marshall Repository II. University Space Research Association - Advanced Design Program Dr. Vicki Johnson Ms. Kay Nute Ms. Barabra Rumbaugh Ms. Cissy Novak Mr. John Sevier Special thanks to Ms. Sue McCown III. NASA- Johnson Space Center James E. Simpson Navigation and Guidance Systems Branch Eric Christensen IV. NSWC-White Oak MD Dr. William T. Messick V. West Virginia University A. Department of Mechanical and Aerospace Engineering Dr. Timothy L. Norman Assistant Professor Dr. Richard Waiters Associate Chairman Dr. Ever J. Barbero Assistant Professor Dr. Alexi Leskin Assistant Professor Dr. Gary Morris Associate Professor ii ABSTRACT CONCEPTUAL DESIGN OF AN ORBITAL DEBRIS DEFENSE SYSTEM West Virginia University Department of Mechanical and Aerospace Engineering West Virginia University Dr. Timothy L. Norman, Asst. Prof. David E. Gaskin, NASA/USRA Grad. TA Man made orbital debris has become a serious problem. Currently NORAD tracks over 7000 objects in orbit and less than 10% of these are active payloads. Common estimates are that the amount of debris will increase at a rate of 10% per year. Impacts of space debris with operational payloads or vehicles is a serious risk to human safety and mission success. For example, the impact of a 0.2 mm diameter paint fleck with the Space Shuttle Challenger window created a 2 mm wide by 0.6 mm deep pit. The cost to replace the window was over $50,000. Twenty-three West Virginia University students conducted a conceptual design of an Orbital Debris Defense System (ODDS). The WVU design considered the wide range of debris sizes, orbits and velocities. Two vehicles were designed to collect and remove space debris. The first vehicle would attach a re-entry package to de-orbit very large debris, e.g. inactive satellites and spent upper stages that tend to break up and form small debris. This vehicle was designed to contain several re-entry packages, and be refueled and resupplied with more re-entry packages as needed. The second vehicle was designed to rendezvous with and capture debris ranging from 10 cm to 2 m. Due to tracking limitations, no technically feasible method for collecting debris below 10 cm in size could be devised; it must be accomplished through international regulations which reduce the accumulation of space debris. • .' • • . ." • . : "0 .." " , ,. ' ' . ., . .- ;',..._.,,_._..,'.. • - :.. __..._.,..,: ..- .-__.2_. "'.._'_J.:_'_ .. • . _--,...:_.- .._,_,i_:: . • .. __-::.. .... '.t: _"_"" "'. • ...... . . FOREWORD Orbital debris is becoming a concern for all nations involved in space research and exploration. NORAD currently tracks over 7000 objects orbiting the Earth with a size of ten centimeters or larger. Less than five percent of these object, however, are active satellites. The remnants are considered orbital debris. There are also thought to be millions more smaller objects in orbit, too small to be detected from the ground. The largest concentrations of satellite objects are located at inclinations of 20 to 30 degrees and 60 to 70 degrees. Orbits around 800, 1000, and 1500 kilometers contain the greatest concentration of objects. These are the altitudes and orbits used regularly for American space efforts. Geosynchronous orbit, where many communications and observation satellites are placed, has a growing population of objects, though it is evenly distributed around the planet. Current estimates put the growth rate of orbital debris at 10% per year. Because of the possible complications of space operations in the future resulting from collisions or avoidance of space debris, it has been suggested by several agencies, including NASA and the AIAA, that a solution to the problem be studied now and implemented as soon as possible. The students of West Virginia University NASA/USRA design class have taken on the goal of reducing the space debris problem. To this end, they have concentrated on designing an orbital debris defense system. iv TABLE OF CONTENTS ACKNOWLEDGEMENTS i ABSTRACT ii ,oo FORWARD 111 ACRONYMS vi SECTION A: SYSTEMS INTEGRATION A1. Problem Statement A1 A2. Design Objectives A1 A1 A3. Executive Summary SECTION B: MEDIUM DEBRIS B1. Section Design Philosophy B1 B2. Design Development B1 B2.1 Passive Collection B1 B2 B2.2 Quick Response System B2.3 Impact Collector B3 B2.4 Cutter/Grinder System B3 B3. Conceptual Design B4 B3.1 Mission Scenario B4 B3.2 Layout B5 B5 B3.3 Propulsion B6 B3.4 Power Requirements B4. Conclusions B6 SECTION C: LARGE DEBRIS C1 CI. Design Philosophy C1.1 Definition of Problem C1 C1 C 1.2 Background C2 C1.3 Objective C2. Design Evolution and Development C2 C2.1 Debris Collection Unit C2 C2.2 Satellite Collection Unit C4 C3. Deorbit Modular Vehicle (DMV) C6 C3.1 Mission Scenario C6 C3.2 Structural Description C8 C3.3 Operational Components C9 C3.3.1 Propulsion C9 C3.3.2 Power C9 C3.3.3 Guidance, Navigation and Control C10 C3.3.4 Tracking Cll C3.3.5 Resupply Cll C3.3.6 Orbital Deployment Cll C3.4CaptureAssembly Cll C3.4.1 Spin Ring C12 C3.4.2 Robotic Arm C13 C3.4.3 End Effector C13 C3.5 Deorbit Modules (DOM) C15 C3.5.1 Attachment C15 C3.5.2 Propulsion C20 C4. Conclusions C21 SECTION D: SHIELDING D1. Section Design Philosophy D1 D2. Description of Shields D1 D2.1 Basic Shields D1 D2.2 Advanced Shields D2 D3. Analysis of Shielding Technology D3 D4. Results D5 D4.1 Mesh Double Bumper D5 D4.2 Multi-Shock D6 D5. Conclusions D7 SECTION E: DETECTION/TRACKING El. Ground Based Tracking Systems E1 E2. Large Debris Collection E3 E3. Medium Debris Collection E3 E4. Conclusions E3 CONCLUSIONS FI RECOMMENDATIONS FI REFERENCES F2 vi ACRONYMS CCD Charge Couple Device DMV Deorbit Modular Vehicle DOM Deorbit Module GEO Geosynchronous Orbit GNC Guidance Navigation Control HIT-F Hypervelocity Impact Test Facility JSC Johnson Space Center MDB Mesh Double Bumper MS Multi Shock ODDS Orbital Debris Defense System OMV Orbital Maneuvering Vehicle USSPACECOM United States Space Command vii SECTION A: SYSTEM INTEGRATION 3. Research Tracking and Detection methods to improve the definition and capability to David Cribbs deal with the space debris problem. AI. Problem Statement. Orbital debris A3. Executive Summary. Space debris has is becoming a concem for all nations become a significant problem for nations involved in space research and exploration. interested in continued exploration and NORAD currently tracks over 7000 objects development of the space environment. The orbiting the Earth with a size of ten Orbital Debris Defense System (ODDS) centimeters or larger A'. Less than five deals with the space debris problem on all percent of these objects, however, are active levels. satellites ^2. The remnants are considered orbital debris. There are also thought to be The nature and history of space debris has millions more smaller objects in orbit, too been researched extensively to gain a better small to be detected from the ground. understanding of the problem and how Current estimates put the growth rate of previous efforts to deal with the problem orbital debris at 10% per year A3.Because of were developed. Each segment of the debris the possible complications of space environment, grouped by size, small (< 10 operations in the future resulting from cm), medium (10cm to 2 m), and large (> collisions or avoidance of space debris, it 2m) pose a different problem, and require a has been suggested by several agencies, different solution. The biggest source of new including NASA and the AIAA, that a debris, is old debris breaking up into smaller solution to the problem be studied now and pieces. The obvious solution is to remove implemented as soon as possible At. the most debris from orbit and do not contribute any more debris to the problem. A2. Design Objectives. The overall goal was to understand the space debris problem In this design, each debris size was dealt abd potential solutions. Thus, the design with individually. To remove the most objective was to perform a conceptual massive pieces of debris, a vehicle was design for the Orbital Debris Defense designed to deorbit large satellites and spent System (ODDS). The conceptual design of upper stages. A second vehicle was designed The ODDS considered the following: to collect medium debris for removal from orbit. Shielding technology was investigated 1. Develop systems to positively impact to deal with the small debris population and debris population in the following size use with orbital debris collection vehicles. range: a. Greater than 2m. b. 2m. to 10 cm. c. less than 10 cm. 2. Research shielding technology for use in high debris population environments. A1 SECTION B: MEDIUM DEBRIS basically relied on flux models to collect debris. They are put into orbit with no Section Design Philosophy specific path and collect debris by randomly colliding with it. The frequency of those As part of the Orbital Debris Defense random collisions is predicted through mathematical models called flux models _ System, the Medium Debris Collection Group was assigned to address debris in the (Figure B.2). The passive collector, size range from 0.1 meters to 2.0 meters. therefore, is characterized by lower fuel Research revealed that there were consumption but lower collection rate, lower approximately 7000 pieces of debris within maneuverability, and much larger size. this range BI and that these pieces of debris were concentrated mainly in orbits of 800 kin, 1000 kin, and 1500 km B2(Figure B. 1). ..'."_ ,_ "_-: D r..... _'- !- 200 ....... Figure B.2 Debris flux graph. J The following sections contain a summary of various design configurations that were considered. A more in-depth discussion of 0 SO0 10_0 1500 2O0O the most promising of those designs follows. I_ll_rll 1-11. Allit_l! Oistlikutloa ofObiecls Imtaw Eaflh OdJi! B1. Design Development Figure B.1 Debris concentration at various altitudes. BI.1 Passive Collection. As a beginning, the Medium Debris Collection Group The goal of the group was to collect as attempted to design a passive debris many pieces of debris as possible in the high collector. The group decided to develop the concentration areas. idea of a butterfly net. The looseness (free- Current proposals to remedy the situation flowing) of the net would help to absorb an fell into one of two categories, active or impact with debris. The net would have passive collection. Active collectors seek plenty of storage capacity and would need out individual pieces of debris and are little maintenance. A conceptual drawing characterized by high fuel consumption. can be seen in Figure B1.1.1. Passive collectors (or sweepers), on the other hand, are much larger satellites that BI However, as Andrew Petro stated,'In collection based on the flux model, forced order to be effective, the sweepers would the group to radically modify the design. B1.2 Quick Response System. Identifying the collision or explosion of large debris as the main source of medium debris, a smaller, more mobile net was developed that would identify where a collision would occur or had just occurred and could be sent to sweep the area before the debris had a Figure BI.I.1. Schematic of debris chance to spread out. As shown by Figure particle with diameter d approaching B1.2.1. BT, after an explosion, debris begins a single sheet shield of thickness t,,. to encircle the earth. have to be enormous .... (with areas) of a square kilometer or more.a3, To make an estimate of the weight of the net, it was assumed that the net could be modeled as a flat plate with a cross-sectional area of one tim . O_s_w IN7 square kilometer and a thickness one centimeter. Using a composite material, the weight of the net was found to be 13.9 million kg. In comparison, the weight of the space shuttle is 69,039 kg. a4 Not only J_r tim _ INS can the net not be launched using the shuttle engines, it could not be launched using the Titan IV-D, the launch vehicle chosen by the group. The Titan can launch 17,700 kg into low earth orbit. B5 4peQ tN8 The issue of avoiding working satellites, _lm 8P01" It,'l _ Ids_. and therefore controllability of the net, became a problem. Further research also Figure B1.2.1 Debris distribution of revealed problems with manufacturing a net Ariane rocket explosion. of such size. It was found that a basal weaving system which uses a loom to form With a Quick Response System, the debris fabric in long, wide strips, would be most would be collected faster after a collision, suited for this purpose. However, the net thus keeping the debris area to a minimum. needed to be a kilometer wide and would This design forced the group to examine therefore require stitching several strips what the goal was. The group wanted to together by hand. There would then be no collect as many pieces of existing debris as guarantee that the net would hold. _ These possible. This design would wait for debris to be made before it would be sent to collect problems, combined with the infrequency of B2