CONTENTS
(Volume 76, Advances in the Astronautical Sciences, Astrodynamics 1991)

Page

FOREWORD, Horace Jacobs vii

Part I

ORBIT DETERMINATION 1

Improving Sequential State Estimates in Ill-Conditioned Angles-Only Tracking Problems Using Sequential Ridge-Type Estimation Algorithms (AAS 91-350), David A. Cicci, Roger L. Hall 3

Modifications to Encke’s Method for Long Arc Orbit Determination Solutions (AAS 91-351), J. B. Lundberg, S. Bettadpur, R. J. Eanes 13

Gravity Field Covariance Analysis for the Topex/Poseidon Mission (AAS 91-353), G. W. Rosborough, W. I. Bertiger, J. T. Wu, S. C. Wu 25

Boost and Post-Boost Target State Estimation With Angles-Only Measurements in a Dynamic Spherical Coordinate System (AAS 91-355), J. L. Fowler 41

A Numerical Approach to the Angles-Only Initial Orbit Determination Problem (AAS 91-356), Mark T. Lane 55

Modeling Radiation Forces Acting on Satellites for Precision Orbit Determination (AAS 91-357), J. A. Marshall, P. G. Antreasian, G. W. Rosborough, B. H. Putney 73

Autonomous Orbit Determination for Earth-Orbiting Spacecraft Utilizing a Maximum Likelihood Filter (AAS 91-352) Abstract, Thomas L. Mullikin, Scott H. Vaughan 97

Navigation Accuracy Analysis for the TDRSS Onboard Navigation System (TONS) Experiment on EP/EUVE (AAS 91-354) Abstract, C. J. Gramling, A. C. Long, T. Lee, N. A. Ottenstein, M. V. Samii 98

Short Arc Initial Orbit Determination Using Angles-Only Space Based Observations (AAS 91-358) Abstract, Denise A. Kaya, Daniel E. Snow 99

EUROPEAN SPACE PROGRAM 101

Exploitation of Doppler Data During the Reactivation of Giotto (AAS 91-359), T. A. Morley 103

Multi-Sun-Synchronous (MSS) Orbits for Earth Observation (AAS 91-361), Carlo Ulivieri, Luciano Anselmo 123

On-Board Low-Earth Orbit Determination (AAS 91-362), C. Jayles, H. Renault 135

Orbit Design and Analysis for the Atmospheric and Environmental Research Satellite ATMOS (AAS 91-363), E. F. Jochim 143

Apogee Manoeuvre Strategies for the INMARSAT-2 Spacecraft (AAS 91-364), Eric Cazala-Hourcade 161

Positioning of EUTELSAT II Satellite From Supersynchronous Transfer Orbit to Reduce Satellite Velocity Correction Requirements (AAS 91-408), Alois F. Leibold 185

Precise Orbit Determination of SPOT Platform with DORIS (AAS 91-409), F. Nouel, J. P. Berthias, P. Broca, M. Deleuze, A. Guitart, P. Laudet, C. Pierret, A. Piuzzi, C. Valorge 207

Hermès Rescue Trajectories (AAS 91-410), Philippe Delattre, Jean-François Goester 225

Dynamic-Free Bias-Free Differential GPS:  Application to Landing (AAS 91-413), M. Martín Neira, R. Lucas 249

An Efficient Numerical Method for Orbit Computations (AAS 91-414), M. Palacios, A. Abad, A. Elipe 265

ITALSAT AOCS Advanced Flight Simulator:  Development and Testing of an Optimal Control Approach for Attitude Control (AAS 91-411) Abstract, G. Lenzo, R. L. Minciotti, M. Sasso 275

ORBITAL DEBRIS 277

Defining the Background Status of a Debris Cloud (AAS 91-365), Timothy D. Maclay, Ronald A. Madler, Roger McNamara, Robert D. Culp 279

Collision Probability Estimate Method for Impact Generated Low Earth Orbit Space Debris Clouds (AAS 91-369), John W. Frye 287

Debris Hazard for the Earth Observing System (AAS 91-370), Ronald A. Madler, Timothy D. Maclay, Roger McNamara, Robert D. Culp 311

Space Debris Measurement and Modeling (AAS 91-371), Phan D. Dao, Ross McNutt 323

Long-Term-Evolution of Uncontrolled Geosynchronous Orbits:  Orbital Debris Implications (AAS 91-372), John D. Vedder, Jill L. Tabor 335

Determination of Acceptable Launch Windows for Satellite Collision Avoidance (AAS 91-373), Gordon D. Bredvik, James E. Strub 345

Development of Orbital Debris Spacecraft Breakup Models (AAS 91-366) Abstract, William J. Tedeschi, John C. Connell, Darren S. McKnight 357

Trajectory Analysis and Issues Associated with the EXCALIBIR Mission (AAS 91-368) Abstract, R. S. Klucz, M. R. Dickey, R. D. Culp 358

FLEXIBLE BODY DYNAMICS AND CONTROL 359

Momentum Exchange:  Feedback Control of Flexible Spacecraft Maneuvers and Vibration (AAS 91-375), Zhong Li, Peter M. Bainum 361

Hà Optimized Broadband Compensator for Wave-Absorbing Control (AAS 91-377), Hironori Fujii, Khoichi Matsuda, Toshiyuki Ohtsuka 379

Dynamic Modeling and Optimal Control of Spacecraft With Flexible Structures Undergoing General Attitude Maneuvers (AAS 91-378), Yiing-Yuh Lin, Gern-Liang Lin 395

Stability Study of Flexible Dual Spin Satellites with Guy Wire Constraints (AAS 91-379), A. P. Mazzoleni, A. L. Schlack 411

Matrix Method for Eigenvalue Assignment:  The Single Input Case (AAS 91-380), S. Pradhan, V. J. Modi, M. S. Bhat 427

Distributed Control Without Mode Shapes or Frequencies (AAS 91-382), Victor D. Lupi, Hon M. Chun, James D. Turner 447

Dynamics of the Orbiter Based WISP Experiment (AAS 91-452), V. J. Modi, A. M. Ibrahim 471

A Recursive Order-N Formulation for DISCOS with Topological Loops and Intermittent Surface Contact (AAS 91-455), Hon M. Chun, James D. Turner, Harold P. Frisch 493

Distributed Parameter Multibody Dynamics Modeling (AAS 91-456), Hon M. Chun, James D. Turner, Victor Lupi 513

Joint Based Inversion Control for Trajectory Tracking of the Mobile Servicing System (AAS 91-458), F. Karray, V. J. Modi, J. K. Chan 527

Pointing and Tracking Control for Freedom’s Solar Dynamic Modules and Vibration Control of Freedom (AAS 91-459), Roger D. Quinn, Jiunn-Liang Chen 549

The Influence of Torsional Appendage Vibration on the Attitude Motion of a Dual-Spin Satellite Via the KBM Method (AAS 91-460), Mark C. Stabb, A. L. Schlack 569

The Application of Linear Actuators for Telescope Pointing Control (AAS 91-536), C. K. Carrington, B. G. Davis 581

Hybrid Control System for Space Mast Structures (AAS 91-374) Abstract, Wisjnu P. Marsis, Peter M. Bainum 601

Reduced Models for the Dynamics and Control of Large Space Structures Via Direct Numerical Optimization Methods (AAS 91-376) Abstract, G. A. Becus, B. S. Martin 602

Control of Spin-Up and Slewing of the WISP Shuttle-Antennae System (AAS 91-453) Abstract, Arun K. Banerjee 603

Determination of Damping Matrices for Components of Large Structures (AAS 91-457) Abstract, F. O. Eke 604

ATTITUDE DYNAMICS AND CONTROL 605

Discrete Dynamics Modeling of a Rigid Body Moving on a Flexible Structure (AAS 91-399), Achille Messac, Deborah Herman 607

Attitude Determination and Dynamical Performance in Free Drift for Space Station Freedom (AAS 91-400), C. F. Burmeister 627

Spinup Dynamics of Axial Dual-Spin Spacecraft (AAS 91-403), C. D. Hall, R. H. Rand 641

Analytic Solutions for the Attitude Motion of Spinning Rigid Bodies Subject to Periodic Torques (AAS 91-404), P. Tsiotras, J. M. Longuski 661

Attitude Motion of a Rigid Body Subject to Polynomial Torques (AAS 91-405), J. M. Longuski, P. Tsiotras 679

An Extended Gyrocompassing Controller for the TOPEX/POSEIDON Spacecraft (AAS 91-479), P. A. Sanneman, B. B. Lee, R. V. Welch 691

Further Investigation of Anomalous Attitude Motion of a Spin-Stabilized Upper Stage (AAS 91-480), J. Y. Kang, J. E. Cochran, Jr. 705

Attitude Maneuvers of a Solar-Powered Electric Orbital Transfer Vehicle (AAS 91-481), Alan B. Jenkin 723

Solar Panel Tracking in Low Earth Orbit With Earth-Oriented Spacecraft (AAS 91-482), W. D. Kelly, C. D. Hill 743

A Kalman Filter for a Gravity Gradient Satellite (AAS 91-483), Peter J. Melvin 763

On-Board Attitude Determination for the Explorer Platform Satellite (AAS 91-484), C. P. Jayaraman, B. Class 783

Star Trackers, Star Catalogs, and Attitude Determination:  Probabilistic Aspects of System Design (AAS 91-485), John D. Vedder 801

Survey of Solar-Sailing Configurations for Satellite Attitude Control (AAS 91-486), George A. Kyroudis 815

Ground Verification for High-Accuracy On-Board Antenna Drive Control System (AAS 91-487), Hiroshi Tanaka, Yoichi Kawakami 839

Dynamics and Control of a Tumbling Satellite Retrieval Device (AAS 91-401) Abstract, Jon M. Neff, Wallace T. Fowler 857

TALON and CRADLE - Systems for the Rescue of Tumbling Spacecraft and Astronauts (AAS 91-402) Abstract, Dunning Idle V 858

Feedforward/Feedback Control Law for Near Time-Optimal Spacecraft Reorientation (AAS 91-406) Abstract, Robert M. Byers, S. R. Vadali, Thomas C. Pollock 859

An Aerocapture Attitude Control System Incorporating Robustness and Vehicle Parameter Identification (AAS 91-407) Abstract, James R. Bell, Edward V. Bergmann, Walter M. Hollister, Lester L. Sackett 860

Part II

MISSION ANALYSIS 861

Interleaving Magellan Altimetry Data Acquisition Between Mapping Cycles 1 and 2 (AAS 91-390), D. B. Engelhardt, C. M. Diarra, D. T. Lyons, M. S. Ryne 863

Magellan Ephemeris Improvement Using Synthetic Aperture Radar Landmark Measurements (AAS 91-391), Paul W. Chodas, Tseng-Chan Wang, William L. Sjogren, John E. Ekelund 875

A Gravity Field Comparison and Analysis to Support Magellan Navigation (AAS 91-392), G. R. Kronschnabl, J. B. McNamee, D. B. Engelhardt, E. J. Graat 891

Orbit Determination for Magellan and Pioneer 12 Using Same-Beam Interferometry (AAS 91-393), W. M. Folkner, D. B. Engelhardt, J. S. Border, N. A. Mottinger 909

Contribution of Doppler and Interferometric Tracking During the Magellan Approach to Venus (AAS 91-394), E. J. Graat, M. S. Ryne, J. S. Border, D. B. Engelhardt 919

Simulations of Lunar Gravity Field Determination for Lunar Observer (AAS 91-395), Alex Konopliv 941

Interplanetary Mission Design for the Comet Rendezvous Asteroid Flyby Mission (AAS 91-396), S. N. Williams, P. C. Knocke, L. E. Bright 957

Mission Options for Rendezvous With the Most Accessible Near-Earth Asteroid - 1989 ML (AAS 91-397), Jim V. McAdams 977

Low Energy Near-Earth Asteroid Flyby Missions (AAS 91-398), Carl G. Sauer, Jr. 993

Galileo Orbit Determination for the Venus and Earth-1 Flybys (AAS 91-470), P. H. Kallemeyn, R. J. Haw, V. M. Pollmeier, F. T. Nicholson, D. W. Murrow 1013

Ulysses Orbit Determination (AAS 91-472), H. J. Gordon, J. L. Luthey, T. P. McElrath, P. R. Menon 1027

Planetary Approach Orbit Determination Using Earth-Based Short and Long Baseline Radio Interferometry (AAS 91-473), Sam W. Thurman, Catherine B. Sybert 1039

Current Trajectory Options for a Comet Nucleus Sample Return Mission (AAS 91-474), Carl G. Sauer, Jr. 1055

Providing Relay Communications Support for the Mars Environmental Survey (MESUR) Mission (AAS 91-475), Byron L. Swenson, Alan L. Friedlander 1071

Utilizing a Space Station as a Transportation Node in a Lunar Exploration Program (AAS 91-476), Lynn A. Wagner, Jr. 1095

Manned Mission to the Planet Mars (AAS 91-478), Thomas J. Dwyer 1117

TOPEX/POSEIDON Orbit Acquisition Maneuver Design (AAS 91-514), Ramachandra S. Bhat 1131

The Role of Predicted Solar Activity in TOPEX/POSEIDON Orbit Maintenance Maneuver Design (AAS 91-515), Raymond B. Frauenholz, Bruce E. Shapiro 1151

Eccentricity and Argument of Perigee Control for Orbits with Repeat Ground Tracks (AAS 91-516), Mark A. Vincent 1171

A Demonstration of Real-Time Connected Element Interferometry for Spacecraft Navigation (AAS 91-517), C. Edwards, D. Rogstad, D. Fort, L. White, B. Iijima 1179

Analysis of the Cosmic Background Explorer (COBE) Helium Venting Through Effects on the Orbit (AAS 91-518), C. M. Cox, G. C. Marr, R. L. DeFazio 1193

Orbital Analysis and Instrument Viewing Considerations for the Earth Observing System (EOS) Satellite (AAS 91-520), Edwin F. Harrison, Patrick Minnis, Gary G. Gibson, Fred M. Denn 1215

The Application of Lissajous Orbits for the SIRTF Mission (AAS 91-521), Martin Lo 1229

Effect of Lunar Gravity Assist on Interplanetary Trajectories (AAS 91-477) Abstract, Walker S. Vaning, John F. Fay 1249

Utilization of Multiple Venus and Earth Gravity Assists for High Energy Interplanetary Missions (AAS 91-519) Abstract, C. L. Yen 1250

ORBITAL ANALYSIS 1251

Solar Sail Trajectories Near the Sun-Earth L₁ Point (AAS 91-425), Cesar A. Ocampo, George W. Rosborough 1253

Frozen Orbits in the J₂+J₃ Problem (AAS 91-426), Krystyna Kiedron, Richard Cook 1273

Influence of Higher Degree Zonals on the Frozen Orbit Geometry (AAS 91-428), George W. Rosborough, Cesar A. Ocampo 1291

Analytic Orbit Plane Targeting for Orbit Transfers About an Oblate Planet (AAS 91-429), R. Leroy McHenry 1305

Uncertainty Estimation for Satellite Lifetime Prediction (AAS 91-431), Felix R. Hoots, Richard G. France 1319

Improvements to Observation Processing at the Space Surveillance Center (AAS 91-432), Kenneth D. Kopke, J. W. Porter 1331

A Cislunar Guidance Methodology and Model for Low Thrust Trajectory Generation (AAS 91-433), David J. Korsmeyer 1353

A Survey of Rendezvous Trajectory Planning (AAS 91-505), D. J. Jezewski, J. P. Brazzel, Jr., E. E. Prust, B. G. Brown, T. A. Mulder, D. B. Wissinger 1373

Coverage Regions:  How They’re Computed and Used (AAS 91-507), Charles K. Wilkinson 1397

Minimal Arbitrarily Phased Constellations With a Given Inclination Providing Single Global Coverage (AAS 91-508), W. S. Adams, R. G. Hopkins 1419

Along Track Formationkeeping for Satellites With Low Eccentricity (AAS 91-510), Jay W. Middour 1431

Orbit Design for Assured Launched Observation (AAS 91-511), John A. Landshof 1447

Approximate Analytic Representations for Low-Thrust Trajectories (AAS 91-512), D. J. Stewart, R. G. Melton 1455

Painting Phase Spaces to Put Frozen Orbits in Context (AAS 91-427) Abstract, S. Coffey, A. Deprit, E. Deprit 1469

Periodic Gravitational Perturbations for Conversion Between Osculating and Mean Orbit Elements (AAS 91-430) Abstract, Joseph R. Guinn 1470

Six Degree of Freedom Trajectory Planner for Spacecraft Proximity Operations Using an A* Node Search (AAS 91-506) Abstract, John F. Raquet, Edward V. Bergmann, Walter M. Hollister 1471

On Star-Shaped Configurations for Stationary Satellite Systems (AAS 91-509) Abstract, W. Stuiver 1472

Orbit Raising With Low Thrust Tangential Acceleration in the Presence of Earth Shadow (AAS 91-513) Abstract, Jean A. Kechichian 1473

MARS MISSION ANALYSIS 1475

Candidate Mars Local Navigation Infrastructures (AAS 91-496), Timothy J. Brand, Stanley W. Shepperd 1477

A Low Cost/Low Complexity Concept for the Mars Sample Return Mission (AAS 91-498), R. T. Gamber, G. L. Adams 1495

Use of Multiple Lunar Swingby for Departure to Mars (AAS 91-499), John M. Hanson, A. Wayne Deaton 1513

Minimum Impulse Trajectories for Mars Round Trip Missions (AAS 91-500), Glen M. Horvat, Stephen W. Alexander 1527

Position Determination of Spacecraft at Mars Using Earth-Based Differential Tracking (AAS 91-502), Robert D. Kahn, William M. Folkner, Charles D. Edwards, A. Vijayaraghavan 1545

Mission Maps for Use in the Choice of Specific Impulse for Manned Mars Missions (AAS 91-503), W. W. Madsen, J. E. Neuman, T. S. Olson, A. S. Siahpush 1563

Elliptical Rendezvous at Mars (AAS 91-504), Nick G. Smith, Philip E. Hong 1573

Optimization of Vehicle Weight for Mars Excursion Missions (AAS 91-497) Abstract, Melvin J. Ferebee, Jr. 1587

Mars Entry-to-Landing Trajectory Optimization and Closed Loop Guidance (AAS 91-501) Abstract, Marc R. Ilgen, Raymund A. Manning, Manuel I. Cruz 1588

ORBITAL ANALYSIS:  SPECIAL TOPICS 1589

Determining Satellite Visibility Periods:  Some Geometric Insights (AAS 91-532), Thomas Schmid, Felix R. Hoots 1591

Algorithm Testing for the Gyro-Based, Astronaut-Held Latitude-Longitude-Locator (AAS 91-533), Mark T. Soyka, Peter J. Melvin, Robert F. Higgins, Jr. 1607

Application of Cluster Analysis and Orbit Determination to the Data Association of Multiple Target Tracking in Space (AAS 91-535), Y. Y. Chang, M. M. Crawford, J. B. Lundberg, B. D. Tapley 1627

Effects of Antenna Orientation on GPS Carrier Phase (AAS 91-537), J. T. Wu, S. C. Wu, G. A. Hajj, W. I. Bertiger, S. M. Lichten 1647

Equivalent GPS Measurements for Efficient Estimation Process (AAS 91-538), S. C. Wu, J. T. Wu, W. G. Melbourne 1661

A Conceptual Design for a Codeless GPS Receiver for Space Applications (AAS 91-539), Peter F. MacDoran, George H. Born, Kenneth L. Gold, William S. Schreiner 1671

Monitoring Global Geodynamical Parameter Variations with GPS and Low Earth Satellites (AAS 91-540), S. C. Wu, S. M. Lichten, R. P. Malla 1691

Advances in Robust Flight Design (AAS 91-534) Abstract, Kelvin K. Wong, Sanjeev K. Dhand 1701

PART III

CHAOS, PREDICTABILITY AND STABILITY IN ASTRODYNAMICS 1703

Introductory Remarks on Chaoticity in Dynamics and Orbit Mechanics (AAS 91-383), Victor Szebehely 1705

Predictability Through Invariance (AAS 91-384), Donald J. Jezewski 1711

Approximation of Poincare Sections Arising in Attitude Control (AAS 91-385), Andrew J. Kurdila, John L. Junkins, William L. Kealey, Francis J. Narcowich, Michael P. Bakich 1721

Recent Progress on the Stability Problem With Applications to Celestial Mechanics and Molecular Dynamics (AAS 91-389), Luigi Galgani 1737

Practical Applications of Lyapunov Characteristic Exponents in Celestial Mechanics (AAS 91-386) Abstract, Roger A. Broucke 1743

Chaos Near the Second Equilibrium Point in the Restricted Problem of Three Bodies (AAS 91-388) Abstract, R. Smith, Victor Szebehely 1744

AEROBRAKING 1745

Parameter Optimization of Minimum-Fuel Transfer Orbits Which Include an Atmospheric Skip Segment (AAS 91-416), Craig A. Martell, Frederick H. Lutze 1747

Optimal Plane Change of an Elliptic Orbit During Aerocruise (AAS 91-417), Sudhaker Medepalli, N. X. Vinh 1769

Aerobang: A New Synergetic Plane-Change Maneuver (AAS 91-418), I. M. Ross 1789

Trajectories to the Outer Planets Using Aero-Gravity Assist Flybys of Venus and Mars (AAS 91-419), David F. Bender 1809

Aerobraking Magellan (AAS 91-420), Daniel T. Lyons, William Sjogren, William T. K. Johnson, Durwin Schmitt, Angus McRonald 1821

Interplanetary Trajectory Optimization of Mars Aerobraking Missions With Constrained Atmospheric Entry Velocities (AAS 91-421), Scott A. Striepe, Robert D. Braun, Richard W. Powell, Wallace T. Fowler 1841

Mars Aerocapture Using Continuous Roll Techniques (AAS 91-422), W. H. Willcockson 1859

Aerothermodynamics of the Mars Rover and Sample Return Lander (AAS 91-423), E. F. Zabrensky, D. L. Post, L. A. Cassel, T. P. Shivananda 1883

CFD Application to Flexible Aerobrake Design for Mars Entry (AAS 91-424) Abstract, Donna L. Post, Manuel I. Cruz 1901

SPACE EXPLORATION INITIATIVE 1903

Lunar Transportation Systems Options (AAS 91-436), Norman S. Brown 1905

Libration Point Staging Options for SEI Lunar Missions:  Station Keeping Implications (AAS 91-437), Davy A. Haynes 1921

Mars Trajectory Options for the Space Exploration Initiative (AAS 91-438), John K. Soldner, B. Kent Joosten 1935

Mass Performance Implications of Mars Parking Orbit Selection for Piloted Missions (AAS 91-440), Stephen J. Hoffman 1949

Science Rationale for the Global Access of the Moon (AAS 91-434) Abstract, M. A. Budden, D. B. Eppler 1965

Lunar Mission Design Strategies for the Space Exploration Initiative (AAS 91-435) Abstract, B. K. Joosten, D. B. Weaver 1966

Split Mission Strategies for Piloted Mars Missions (AAS 91-439) Abstract, B. Drake, L. Walters 1967

Evolutionary Nuclear Thermal Rocket for Manned Mars Missions (AAS 91-441) Abstract, A. M. Adams 1968

Relay Satellite Mission Design Considerations for Mars Missions of the Space Exploration Initiative (AAS 91-442) Abstract, S. Matousek 1969

OPTIMIZATION 1971

The Solution of Singular Optimal Control Problems Using Direct Collocation and Nonlinear Programming (AAS 91-443), James R. Downey, Bruce A. Conway 1973

Optimal Cooperative Power-Limited Rendezvous (AAS 91-444), Victoria Coverstone-Carroll, John E. Prussing 1989

RV Strings of Maximum Curvature (AAS 91-445), David G. Hull, Raymond M. Zazworsky 2009

Linear Decentralized Learning Control (AAS 91-447), Soo Cheol Lee, Richard W. Longman, Minh Phan 2023

Techniques for Improving Transients in Learning Control Systems (AAS 91-448), C.-K. Chang, Richard W. Longman, Minh Phan 2035

Sufficient Conditions for a Local Minimum of the Bolza Problem With a Scalar Terminal Point Constraint (AAS 91-449), Lincoln J. Wood 2053

Landing Sites can be Optimally Achieved (AAS 91-523), D. J. Jezewski 2073

Fuel-Optimal Trajectories for Linearized Equations With Application to Keplerian Orbits (AAS 91-525), Thomas Carter, John Brient 2083

Rapid Computation of Multiple Near Earth Asteroid Flyby Opportunities (AAS 91-527), Paul A. Penzo 2097

Disturbance Rejection in Repetitive Controllers (AAS 91-529), Edward J. Solcz, Richard W. Longman 2111

The GLC and Optimality of the Aerocruise Maneuver (AAS 91-530), I. Michael Ross 2131

Shaping of System Responses With Minimax Optimization in the Time Domain (AAS 91-531), Toshiyuki Ohtsuka, Hironori Fujii 2145

Impact Error Scaling Methods for Missile Accuracy Studies (AAS 91-446) Abstract, D. L. Hitzl, A. W. Merz, K. W. Last, B. E. Marshall, J. J. Nakanishi 2165

Sufficient Conditions for a Local Minimum of the Bolza Problem With Multiple Terminal Point Constraints (AAS 91-450) Abstract, Lincoln J. Wood 2166

Sequential Gradient-Restoration Algorithm for Optimal Control Problems With Control Inequality Constraints and General Boundary Conditions (AAS 91-451) Abstract, Estelle M. Eke 2167

Trajectory Optimization With a Modified Set of Equinoctial Orbit Elements (AAS 91-524) Abstract, Jean A. Kechichian 2168

Interplanetary Round-Trip Trajectory Optimization:  Round-Trip Delta-V (RTDV) Plots (AAS 91-526) Abstract, C. D. Hepburn 2169

A Simple Gravity Assist Optimization Tool for Preliminary Mission Planning (AAS 91-528) Abstract, D. Monroe, W. T. Fowler 2170

CELESTIAL MECHANICS 2171

An Analytical Evaluation of Mascon Effects in a Semi-Analytic Theory (AAS 91-461), Ahmed H. Salama 2173

An Analytical Approach to the Motion of the Satellites of Neptune (AAS 91-462), A. M. Segerman, D. L. Richardson 2191

The Long-Term Behavior of Near-Circular Orbits in a Zonal Gravity Field (AAS 91-463), Richard A. Cook 2205

A Doubly Averaging Method for Third Body Perturbations in Planet Equator Coordinates (AAS 91-464), Johnny H. Kwok 2223

A Chebyshev/Störmer Procedure for the Numerical Integration of Second-Order Systems (AAS 91-465), D. L. Richardson 2241

Orbit Perturbations Due to an Axi-Symmetric Gravitational Field, Analyzed Over Extended Periods of Time (AAS 91-466), R. H. Gooding 2249

A Self-Consistent Theory for the Earth’s Rotational Motion (AAS 91-468), C. F. Walker, D. L. Richardson 2271

Analytic Continuation of Quasi-Periodic Orbits From Non-Linear Normal Modes (AAS 91-467) Abstract, Michael E. Hough 2291

Alternative Solution of Kepler’s Equation (AAS 91-469) Abstract, Walker S. Vaning 2292

ATMOSPHERIC DENSITY 2293

Changes of Neutral Composition in the Thermosphere (AAS 91-488), A. G. Burns, T. L. Killeen 2295

Global Dynamic Models of the Earth’s Upper Atmosphere (AAS 91-489), R. G. Roble 2313

Atmospheric Variations Observed From Orbit Determination (AAS 91-492), Daniel E. Snow, Joseph J. F. Liu 2329

Upper Atmosphere Wind Measurements (AAS 91-493), Dwight Sipler 2347

Predicting Short Term Drag Induced Changes in Along Track Positions of Low Altitude Satellites (AAS 91-494), L. Lee Pryor, Paul T. Lasewicz, Wade S. Algee, Dale Synnes 2361

Upper Atmospheric Disturbance Effects on Reentry Satellite Landing Accuracy (AAS 91-495), T. A. Seyler, D. E. Florence 2371

Predicting Solar and Geomagnetic Activity in the 90’s (AAS 91-490) Abstract, G. Heckman 2379

Development and Validation of New Satellite Drag Models (AAS 91-491) Abstract, Frank A. Marcos 2380

TETHERED SATELLITES 2381

Transverse Elastic Oscillations of Three-Body Tethered Systems (AAS 91-542), K. Kumar, O. N. Jha, A. K. Misra, Y. Yan 2383

Equilibrium Configurations in a Tethered Atmospheric Mission (AAS 91-543), Silvio Bergamaschi, Fabrizio Bonon 2397

Dynamics and Control of a Tethered Flight Vehicle (AAS 91-544), T. S. No, J. E. Cochran, Jr. 2411

Further Developments in the Harmonic Analysis of TSS-1 (AAS 91-545), S. Bergamaschi, A. Catinaccio 2431

Planar Motion of a Tethered Satellite-Platform System in a Slightly Elliptic Orbit (AAS 91-546), Clare Savaglio, Nguyen X. Vinh 2449

Orbital Lifetime of Tethered Satellites (AAS 91-548), Ted W. Warnock, John E. Cochran, Jr. 2469

Analysis of Aerocapture With Tethers (AAS 91-549), J. Puig-Suari, J. M. Longuski 2487

Pointing Control, With Tethers as Actuators, of a Space-Station-Supported Platform (AAS 91-541) Abstract, Arun K. Banerjee, Thomas R. Kane 2503

A New Approach to Space Missions Involving a Long Tether (AAS 91-547) Abstract, Ehud Netzer, Thomas R. Kane 2504

APPENDICES 2505

The Effect of Solar Cycle Variations on the Thermosphere AAS 89-416), F. G. McCormac, T. L. Killeen, A. G. Burns, F. A. Marcos, R. G. Roble 2507

Publications of the American Astronautical Society 2531

Advances in the Astronautical Sciences Series 2532

Science and Technology Series 2537

AAS History Series 2542

INDEX 2543

Numerical Index 2545

Author Index 2555