Reaching High Altitudes on Mars With an Inflatable Hypersonic Drag Balloon (eBook)

Dr. Hannes Griebel completed his doctoral thesis under the supervision of Prof. Dr. Bernd Häusler at the Department of Aerospace Engineering at the Universität der Bundeswehr, München. He was ARCHIMEDES Chief Engineer and Programme Manager and is currently working as a Senior Spacecraft Operations Engineer for Mars Express.

Acknowledgements 7
Table of Contents 8
List of Figures 11
List of Tables 21
List of Symbols 22
List of Constants 24
Acronyms and Abbreviations 25
1 Introduction 27
1.1 Scientific Background 27
1.2 Engineering Background 28
2 Related Technologies and State of the Art 29
2.1 About Planetary Aeroplanes and Balloons 29
2.2 About Automatie Inflatables 30
2.2.1 Gas Generator Systems 30
2.2.2 Compressed Gas Systems 31
2.2.3 Cryogenic Gas Storage Systems 32
2.2.4 General Motors' Air Cushion Restraint Syatem from 1973 to 1976 32
2.3 About Space Inflatableas 34
2.4 About Hypersonic InflatabIe Drag Devices 35
2.4.1 TM Goodyear Ballute 36
2.4.2 The Gemini Ejection Seat Recovery System 37
2.4.3 IRDT 38
2.5 State of the Art 39
3 Basic Considerations on Probes with Low Ballistic Coefficients 41
3.1 The Spacecraft Elements 41
3.1.1 The Ballute Spacecraft 41
3.1.2 The Service Spacecraft and Mission Infrastructure 42
3.1.3 Basic Simplification 42
3.2 Basic Equations of Motion 43
3.3 About Atmosphere Models and Their Suitability 44
3.4 The BaUistic Coefficient and Its Impact on Mission Design 48
3.5 Entry Angle and Entry Altitude 52
4 Ballute Spacecraft Configuration Options 58
4.1 General Ballute Shapes and Attachment Options 58
4.2 Final Configuration 59
4.3 Mission Design Options 60
4.3.1 Descending to a Flotation Altitude 61
4.3.2 Descending to the Surface of Mars 66
4.3.3 Aerobreaking before Descending Deeper into the Atmosphere 67
5 Flight Dynamics Analysis 69
5.1 Overview 69
5.2 Mission and Sensitivity Analysis with the Radio Science Simulator 69
5.2.1 Atmospheric Entry Trajectories 70
5.2.2 Mission Design Analysis 72
5.3 Aerothermodynamics and Aeroelasticity 74
5.3.1 Computational Fluid Dynmnics Analysis of Critical Trajectory Points 74
5.3.2 FEM Stress and Modal Analyaes 78
5.4 Thermal Analysis 83
5.4.1 Overview and Coordinate System 83
5.4.2 Basic Equations 84
5.4.3 Radiative Beat Exchange 85
5.4.4 Example Results 89
6 Material Analysis 91
6.1 Material Selection 91
6.2 Test and Rasults 93
6.2.1 UPILEX® 93
6.2.1.1 Mechanical Tests 93
6.2.1.2 Outgassing Tests 95
6.2.1.3 Thermo-Optical Properties 95
6.2.2 PBO 97
6.3 Conclusion 101
7 Ballute 102
7.1 System Design 102
7.2 Theory of Operation (Ballute Theory) 103
7.2.1 An Approximate Analytical Method to Determine the Desired Ballistic Coefficient and Ballute Performance 105
7.2.1.1 Basic Simplifications 105
7.2.1.2 The Velocity as a Function of Altitude 108
7.2.1.3 Maximum Deceleration 109
7.2.1.4 Maximum Hypersonie Heating Rate 114
7.2.1.5 Maximum Stagnation Point Pressure 117
7.2.2 Determination of the Required Inflation Pressure Range 119
7.2.3 Accessible Landing Terrain, Usable Altitude Range and Usable Descent Time 124
7.2.3.1 Transition Through Mach 1 124
7.2.3.2 Final Descent of a Super Pressurized Ballute 128
7.2.3.3 Final Descent of a Collapsing Ballute 132
7.2.4 Sizing the Ballute 139
7.2.5 Sizing the Fittings 147
7.3 Design Considerations 149
7.3.1 General Layout Considerations 149
7.3.2 Envelope Production Patterns and Segments 150
7.3.2.1 The FootbaIl (Soccer) Pattern 152
7.3.2.2 Geodesic Sphere 153
7.3.2.3 The Beach Ball (Orange Peel) Pattern 154
7.3.2.4 The Necessary Number of Segments 155
7.3.3 Fittings and Reinforcements 158
7.3.4 Seams 159
7.3.4.1 Seam Geometry 159
7.3.4.2 Seams with Adhesive Tapes 161
7.3.4.3 Heat Bonded (Welded) Seams 167
7.3.5 Ballute Instrumentation 170
7.4 Manufacturing Considerations 174
7.4.1 Envelope Parts 174
7.4.2 Envelope Assembly 176
8 TransportatIon and Deployment System 178
8.1 Statement of Purpose 178
8.2 System Design 178
8.3 Theory of Operation 179
8.3.1 General Principle 179
8.3.2 Protective Atmosphere 179
8.4 Ballute Packaging 181
8.4.1 General Principle 181
8.4.2 Packaging Efficiency and Trapped Gas 181
85 Deployment Tests 187
8.5.1 Parabolic Flight Deployment Test 187
8.5.2 REGINA In Space Deployment Test 189
9 Inflation Control and Gas Storage System (lGSS) 192
9.1 System Design 192
9.2 Theory of Operation 196
9.2.1 General Overview 196
9.2.2 Mathematical Description and Simulation 197
10 Mission and Spacecraft Design for Ballute Applications 201
10.1 Principal Mission and Spacecraft Design Guide 201
10.2 The MIRIAM Spaceflight Test 203
10.2.1 General Mission and Spacecraft Overview 203
10.2.2 Instrumentation and Methods to Achieve the Mission Goals 208
10.2.3 Instrument Pod 209
10.2.4 Trajectory and Aerothermodynamic Analysis 211
10.2.5 Ballute 213
10.2.6 Deplayment and Inflation Subsystems 216
10.2.6.1 IGSS System Design Overview 218
10.2.6.2 The Inflation Control Command sequeece 221
10.2.7 Filght Report and Conclusion 226
10.3 Tbe ARCHIMEDES Mars Balloon Probe 230
10.3.1 Scientific Mission and Payload Instruments 230
10.3.2 Mars Mission System Elements 231
10.3.2.1 The ARCHIMEDES Ballute Spacecraft 232
10.3.2.2 The Joint Propulsion System (ARCHlMEDES' Service Spacecraft) 234
10.3.3 Mission Design 236
10.3.3.1 Trajectory 236
10.3.3.2 Telecommunication and Power Budgets 240
10.3.3.3 Thermal Environment and Hypersonic Flow 245
10.3.4 Concluaion 247
10.4 Other Applications 248
10.4.1 The ARCHIMDES-V Venus Ballute Probe 248
10.4.2 Sky Raft: Recovery from Earth Orbit 248
11 Conclusion and Outlook 251
Bibliography 252