Satellite Engineering PROBA Family

Satellite Engineering PROBA Family Ir. Julien Tallineau Business Development Manager Tel: +32 3 250 14 14 (general) Tel: +32 3 250 43 43 (direct) Fax:+32 3 253 14 64 Julien.tallineau@qinetiq.be Presentation to ULg (09/12/15) Satellite Design Lecture Copyright QinetiQ Limited 2012 QinetiQ Proprietary 1

0 TABLE OF CONTENT 1. INTRODUCTION 2. SMALL SATELLITE BUSINESS 3. PROBA SATELLITE 4. PROBA CASE STUDY 5. CONCLUSION & OPPORTUNITIES 2

1 INTRODUCTION 3

1 INTRODUCTION What is a small satellite for the industry? 4

1 INTRODUCTION What is a small satellite for the industry? ANSWER = A product you can sell for a given price to a customer! NB: small satellite does not have so much of a meaning for industry because they classify their platform not with respect to mass but with respect to application (Sun Imaging, Earth Imaging, ) or product line (P-100; P-200; P-500) 5

1 INTRODUCTION What is the price of small satellite? 6

1 INTRODUCTION What is the price of small satellite? ANSWER = Varies from 5M up to 300M NB: one shot satellite like Hubble or SOHO is not interesting for the industry. 7

1 INTRODUCTION How much profit do you make? ANSWER FOR ESA = 8% Profit is allowed by ESA NB: one shot satellite like Hubble or SOHO is not interesting for the industry. 8

1 INTRODUCTION How much profit do you make? ANSWER FOR COMMERCIAL CUSTOMER = Easily 20% with good negociation skills, political environment and the competitor prices NB: one shot satellite like Hubble or SOHO is not interesting for the industry. 9

1 INTRODUCTION Mandatory ECSS Usefull ECSS 10

1 INTRODUCTION Satellite Engineering 1. Customer Need (Scientist) 2. Creation of System Requirements 3. Phase 0 (CDF Study) 4. Phase A (Feasibility Study) 5. Phase B (Preliminary Design) 6. Phase C (Final Design) 7. Phase D (Manufacturing / Testing) 8. Phase E (Launch / Commissionning & Operations) 9. Phase F (De-orbiting) 11

1 INTRODUCTION Satellite Engineering 1. Customer Need (Scientist) 2. Creation of System Requirements 3. Phase 0 (CDF Study) 4. Phase A (Feasibility Study) 12

1 INTRODUCTION Satellite Engineering 5. Phase B (Preliminary Design) Detailed System Analysis Preliminary Subsystem Analysis Trade-offs 6. Phase C (Final Design) Detailed Subsystem Analysis Procurement Qualification Testing 13

1 INTRODUCTION Satellite Engineering 7. Phase D Manufacturing Acceptance Testing Requirement Verification Shipment to Launch site 14

1 INTRODUCTION Satellite Engineering 8. Phase E Launch Commissionning Operations 9. Phase F (De-orbiting/End of Life) None in this case 15

2 SMALL SATELLITE BUSINESS 16

2 SATELLITE PRODUCT THREE PACKAGES 1. We provide the platform (Established) Excluding Payload 2. We provide the Mission (Established) Including Payload + Launch PROBA-2 Platform QinetiQ Space Payload procured by ESA PROBA-V Platform QinetiQ Space Vegetation Instrument QinetiQ Space FALCON-9 Candidate for future Mission

3 PROBA SATELLITES 18

3 ACHIEVEMENTS PROBA-1 (2001) Earth Imaging Technology Demo PROBA-2 (2009) Sun Observation Technology Demo PROBA-V (2013) Global Vegetation Monitoring Operational Mission 19

3 ACHIEVEMENTS PROBA-1 (2001) Earth Imaging Technology Demo PROBA-2 (2009) Sun Observation Technology Demo PROBA-V (2013) Global Vegetation Monitoring Operational Mission 20

3 PROBA - 2 PROBA 2 Mission 51

3 PROBA - 2 Mission 1. In orbit Demonstration, PROBA-2 aimed at technological innovation. Altogether, 17 new technological developments and four scientific experiments are being flown on Proba-2. 2. Orbital Parameter 52

3 PROBA - 2 Mission 1. RAAN selected for 6:00 AM Local Time Ascending Node 53

3 PROBA - 2 Mission 1. Launcher is Rockot Worst Case separation rate of 8 per sec. Inclination accuracy of 0.05 Altitude accuracy of 12km RAAN accuracy of 3.75 ( 15min LT) 2. Injected via the Breeze upper stage 54

3 PROBA - 2 Mission 55

3 PROBA - 2 Mission 1. Ground segment visibility REDU KIROUNA 56

3 PROBA - 2 Mission 1. Scenario LEOP Commissioning (three months) Nominal Operations 2. Spacecraft Modes Separation Safe Observation Stand-by 57

3 PROBA - 2 Mission 58

3 PROBA - 2 Satellite Design - Configuration 1. Single H Structure 2. Sun Shield Standard STR Bepi-Colombo STR 3. High Unit Density 4. Deployable Solar Panel (x2) 59

3 PROBA - 2 Satellite Design - Mechanics 1. Spacecraft Mass = 122.5 kg 2. CoG Choice Folded Configuration (LV requirement) Deployed Configuration (GNC requirement) NB: LV I/F Ring Mass included 60

3 PROBA - 2 Satellite Design - Power 1. Power budget is positive, independently of the mode Observation (w/o TX) Observation with TX Safe mode with TX (worst Beta-angle). Definition Beta Angle = angle between the Sun-Earth vector and the orbital plane. β = 90 implies max sunlight time β = 0 implies min sunlight time 61

3 PROBA - 2 Satellite Design - Power 62

3 PROBA - 2 Satellite Design - Power 63

3 PROBA - 2 Satellite Design Power 1. Battery DoD (Ah) in function of time 2. Non Regulated bus 28V 64

3 PROBA - 2 Satellite Design - Power 1. Power budget while de-tumbling! 2. Trade-off between: Performance (GNC) Time (LEOP schedule) Battery Discharge (Higher DoD) 65

3 PROBA - 2 Satellite Design - Avionics 1. System is fully redundant 2. Data & Power centralized (ADPMS) 3. Interface Unit AOCS Module Deployment Module Propulsion Module Thermal Control Module 66

3 PROBA - 2 Satellite Design Data & Processing 1. Processing budget shows how busy is the processor with all the units + instruments. On Software Verification Facility On S/C during System Validation Test 5 67

3 PROBA - 2 Satellite Design AOCS 1. Low power resistojet (Xenon) 15W for heater (x2) 50s Isp (min) 20mN Thrust Total V = 2m/s 68

3 PROBA - 2 Satellite Design AOCS 1. Sensors 2 Star-tracker 2 GPS RX 2 Magnetor-Meter 2. Actuators 4 Reaction Wheels 3 dual-coil magneto-torquer 69

3 PROBA - 2 GPS RX 27 000 km 23 000 km 25 000 km Position determination

3 PROBA - 2 Magnetometer (2) Measure continuously the Earth Magnetic field and determine itselve where the North is. N Z Position determination

3 PROBA - 2 Star-Tracker (3) Takes pictures of stars Compare it with its internat catalog. Compute the satellite orientation/position Orientation/Position

3 PROBA - 2 Magnetotorquer (4) Z N N Z Magnetic Coil Align itself to Magnetic lines Orientation/Manoeuvre

3 PROBA - 2 Rection Wheel (4) Accelerates or decelerates while momentum conservation implies the PROBA to rotate the other way. Orientation/Manoeuvre

3 PROBA - V 75

3 PROBA - V Mission 1. Providing Daily Vegetation Global Monitoring Capability to Scientific Community 76

3 PROBA - V Mission 1. RAAN selected for 10:45 Local Time Descending Node. 77

3 PROBA - V Mission 1. Launcher is VEGA Semi-major axis accuracy of 15km Inclination accuracy of 0,15 deg Better than PSLV Inclination accuracy of 0.2 Altitude accuracy of 35km 2. Launch site: Kourou 3. Launch Date: 7th of May 2013 78

3 PROBA - V Mission 1. Ground station selection Svalbard / Kiruna / Fairbanks Payload data downlink REDU for mission control 79

3 PROBA - V Mission 1. Ground station selection Fairbanks & Kiruna overlap! No steerable antenna on board Necessity to interrupt connection RGS 80

3 PROBA - V Mission 1. Scenario Launch and Early Operation Phase (LEOP) Boot after separation & De-tumbling First Ground Contact + AOCS/GPS switched ON Commissioning (two months) Nominal Autonomy High Flexibility Nominal Operations High Autonomy 81

3 PROBA - V Satellite Design - Configuration 1. X-band antenna toward Nadir 2. Solar Array on Velocity, Zenith & Anti Velocity 3. Star Tracker looking as much as possible towards deep space 4. Bottom board for LV interface 82

3 PROBA - V Satellite Design - Structure 1. Double H structure 2. Honeycomb panels Aluminium core Aluminium edge Alumiunium facesheet (Primary structure) CFRP facesheet (Secondary structure) 83

3 PROBA - V Satellite Design - Mechanics 1. Spacecraft Mass = 148 kg 2. Balance Mass of for CoG Location Requirement 84

3 PROBA - V Satellite Design - Power 1. Power budget approach could be: Rely on Solar Array (SA) in Sun and on Battery in Eclipse Rely on both Battery and SA when available. What are the advantages & disadvantages of these approach? 85

3 PROBA - V Satellite Design - Power 1. Power budget approach could be: Rely on Solar Array (SA) in Sun and on Battery in Eclipse Rely on both Battery and SA when available. 2. Power budget reaches up to 123,7W (COM & PLD) 46,5W in safe Mode 86

3 PROBA - V Satellite Design - Power 1. Power > 0 (consumption) & Power < 0 (recharge) 87

3 PROBA - V Satellite Design RF COM 1. Downlink (S-Band) 2235 MHz Data rate = 142kbps (BPSK modulation) Symbol rate = 329 ksps (Convolutional-Reed Solomon Coding) Flux margin of 25dB Telemetry Recovery margin of 3dB 2. Uplink (S-Band) 2058 MHz Data rate = 64kbps Carrier Recovery margin of 20dB Telecommand Recovery margin of 6dB 88

3 PROBA - V Satellite Design RF COM 1. Downlink (X-Band) 8090 MHz Data rate = 33 Mbps OQPSK modulation) Symbol rate = 42 Msps (convolutional coding) Telemetry Recovery margin of 8dB with only 33W input power @Transmitter input 89

3 PROBA - V Satellite Design Data & memory 1. Memory is filled with 1. One instrument ON 2. Two instrument ON 3. Three instrument ON 1. Green = VI-R 2. Red = VI-C 3. Bleu = VI-L 90

3 PROBA - V Satellite Design Memory 1. Memory Mass Memory size = 88Gbit Required = 52,5 Gbit Total Generated = 229,9 Gbit Average data generation = 2,65 Mbps Peak data generation = 12 Mbps (all ON) 2. Ground contact 20 contact per day 8 skipped (assumption) Max time delay = 3,2 hours 91

3 PROBA - V Satellite Design AOCS 1. Guidance = determination of the desired path of travel from the satellite's current location to a designated target 2. Navigation = determination of the satellite s location, velocity and attitude 3. Control Head Head GPS Receiver Star Tracker (2) Magnetometers (2) AOCS Software - Navigation - Guidance - Control Reaction Wheels (4) Magnetotorquers (4) = manipulation of the forces needed to track guidance commands while maintaining satellite stability 92

3 PROBA - V Satellite Design AOCS ( Pointing Modes) Inertial Pointing Earth Pointing Point and Stare Scanning Modes Inertial pointing Sun Pointing Utilisation: Astronomy Solar Physics On-track Off-track Utilisation: Earth Observation Telecommunications Space Weather On-track Off-track Utilisation: High Resolution Imaging Elevation Modeling Disaster Monitoring Motion compensation Multiple scans 93

3 PROBA - V Satellite Design AOCS 1. Specifications Errors at 95% confidence level Absolute Pointing Error (APE) Relative Pointing Error (RPE) Absolute Measurement Error (AME) 20 arcsec 5 arcsec over 10 s 10 arcsec 2. AOCS SW Modes Quiscient Magnetic Celestial Terrestrial Magnetic Mode - Sensor: magnetometer - Actuator: magnetotorquers + 1 RW stby (momentum bias) - Guidance: No - Navigation: No - Control: Bdot Algorithms (Kinetic Energy Dumping) 95

3 PROBA - V Satellite Design AOCS 1. Specifications Errors at 95% confidence level Absolute Pointing Error (APE) Relative Pointing Error (RPE) Absolute Measurement Error (AME) 20 arcsec 5 arcsec over 10 s 10 arcsec 2. AOCS SW Modes Quiscient Magnetic Celestial Terrestrial Celestial Mode - Sensor: Star-tracker + Magnetic mode sensors - Actuator: Reaction Wheels + Magnetic mode actuatord - Guidance: Sun pointing, Inertial pointing - Navigation: Attitude and Orbit evaluator (Kalman Filter) - Control: State feedback, PID, angular momentum control 96

3 PROBA - V Satellite Design AOCS 1. Specifications Errors at 95% confidence level Absolute Pointing Error (APE) Relative Pointing Error (RPE) Absolute Measurement Error (AME) 20 arcsec 5 arcsec over 10 s 10 arcsec 2. AOCS SW Modes Quiscient Magnetic Celestial Terrestrial Terrestrial Mode - Sensor: GPS + celestial mode sensors - Actuator: Same as Celestial mode - Guidance: Nadir, Fixed-target pointing, Imaging scans - Navigation: Same as Celestial mode - Control: Same as Celestial mode 97

3 PROBA - V Launched on the 07/05/2013 from Kourou 98

4 CASE STUDY: PROBA-3 The Mission Phase A Phase B 99

3 PROBA - 3 Mission 1. The PROBA-3 mission will provide an opportunity to validate and develop The Metrology and Actuation techniques / technologies The Guidance strategies and Navigation and Control algorithms necessary for formation flying. 2. One mission, two spacecrafts: Coronagraph S/C (CSC) Occulter SC (OSC) 100

3 PROBA - 3 Mission 1. High Elliptical Orbit (HEO) with 20 hours period Low perturbation in Apogee Low AoP drift (fixed above REDU) Limited Eclipse duration Radition Issue Stringent Constraint on RF Link Delta-V issue. Parameter Value Orbit type HEO Perigee altitude 600km Apogee altitude 60530km Inclination 59 Eccentricity 0.8062 AoP 188 RAAN 173 Epoch Jan 2017 Formation 3km 101

3 PROBA - 3 Possible Launchers 1. PSLV Launcher Low Cost Heritage from PROBA-1 Reduced Volume 2. Falcon 9 Launcher High Cost Higher Performance Large Volume No Heritage PSLV Falcon 9 102

3 PROBA - 3 Which one of the two shall you design your Spacecraft for? 103

3 PROBA - 3 Which one of the two shall you design your Spacecraft for? ANSWER = The Two! But it is up to ESA + Delegates to decide the mission budget 104

3 PROBA - 3 What would you put in your spacecraft? 105

3 PROBA - 3 What would you put in your spacecraft? Subsystem Design Structure Aluminium/CFRP/Invar/Titanium? Thermal Passive/Active? Mechanism Body Mounted/Deployable SA? Power Large/Small SA? Large/Small Battery? GNC RF Sensor? Actuator? High/Low Gain COM Antenna? High/Low Gain FF Antenna? 106

3 PROBA - 3 Welcome in Phase A! 107

3 PROBA 3 Phase A Outcome of Phase A is our STARTING POINT 1. Configuration 2. Mass 3. Power 4. Avionics 5. Thermal 6. Propulsion 7. Link & Data 8. Payload 108

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. From Top 2. From Bottom 109

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. From Back Left 2. From Back Right 110

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. From Front 2. From Inside 111

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. Mass Budget Total CSC dry mass including I/F ring with L/V shall be less than 360kg (with margins). Current estimate: 376.44kg 2. Power Budget Total CSC maximum power consumption shall be less than 294W (with margins) Current estimate: 353.15W 112

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. Avionics Centrilized around Advance Data & Power Management System (ADPMS) Support of Interface Electronics PROBA-V ADPMS Flight Model 113

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. Thermal Solar array temperature range (-169 C to +79 C). Battery operational temperature range: -10 C minimum operational temperature +40 C maximum operational temperature Star Tracker detector maximum operational temperature Current prediction: 40 C Required: 15 C 114

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. Propulsion System (HPGP) Scheme 115

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. Propulsion System (HPGP) Scheme What is the cost? 116

3 PROBA 3 Phase A Coronagraph Satellite Overview 2. Propulsion System (HPGP) 2x4 thrusters to raise orbit Constrains Pre-warming needs 64W (=2x4x8W) during 30 min Propellant needs to be kept above 10 C (Always) Performance Isp = 202 EoL Thrust = 1N 117

3 PROBA 3 Phase A Coronagraph Satellite Overview 3. Propulsion System (Cold Gas) Siwteen thruster for GNC and FF Performance 118

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. GNC Sensors 6 Sun Acquisition Sensors 2x3 Gyros 2x3 Acceleromter 3 Star Trackers Head + 2x1 Electronics 2x1 GPS 3. GNC FF Omni-directional RF Sensor (FFRF) Coarse Lateral Sensor Fine Formation Sensor 2. GNC Actuators 3+1 Reaction Wheels Cold Gas thrusters 119

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. RF Scheme 120

3 PROBA 3 Phase A Coronagraph Satellite Overview 1. Link Budget The CSC shall be able to downlink data at a symbol rates of 256ksps and 2Msps using REDU-3 Ground Station The CSC shall be able to receive TC data at a symbol rates of 64ksps using REDU-3 Ground Station Current estimation: Downlink not closed for 2Msps (@apogee) Uplink not closed for 64ksps (@apogee) 121

3 PROBA 3 Phase A SUMMARY 1. Satellite is too heavy 2. Satellite is too power consuming 3. Satellite is too hot or too cold 4. Satellite is too far to close its downlink and uplink 5. Satellite is too far to downlink its science data 6. Satellite is too un-protected wrt radiations (20krad under 2mm Al) 122

3 PROBA - 3 What can we do? 123

3 PROBA 3 Phase A ANSWER 1. Mass & Power reduction exercise 2. Perform a detailed thermal analysis Active control Electronics Location Radiator size 3. Review Operation concept for U/D link 4. Increase Satellite Shielding + MINIMIZE THE COST! 124

3 PROBA - 3 Welcome in Phase B! 125

3 PROBA 3 Phase B Mass reduction 1. Who are the biggest contributors? 126

3 PROBA 3 Phase B Mass reduction 1. Who are the biggest contributors? Structure Formation Flying Propulsion System Payload 127

3 PROBA - 3 What can we do? 128

3 PROBA 3 Phase B Mass reduction 1. Structure Shield the spacecraft with outer panels! Remove materials in the Bottom Board! Remove two panels while re-arranging structure Shorten the satellite Consider LV I/F ring as part of system mass margin 2. GNC & Propulsion Remove the Accelerometer Remove Cold Gas Propulsion System (Transfer to OSC) Include 2x4 additional HPGP thruster for 6DoF 129

3 PROBA 3 Phase B Mass reduction results 1. Structure has been reinforced (corner bracket) Honeycomb Al-Al-Al (Primary & Secondary Structure ) Honeycomb CFRP-Al-CFRP (Solar Cells accommodation) 2. Satellite has better shielding 3. Mass has decreased to 318kg 130

3 PROBA 3 Phase B Power reduction 1. Who are the biggest contributors? Thermal control = 91W (due to propellant thermal constraint) Propulsion (HPGP) = 128W (16x8W after the mass reduction) Payload = 40W (pre-warming) Reaction Wheel = 42W (when 3 accelerating + 1 constant speed) 2. Still to be included within the 294W 30% 43% 13% 13% 99% STR / Gyro / GPS / RF systems / On-Board Computer / Propulsion Electronics / 131

3 PROBA 3 Phase B Power reduction 1. Thermal Control Satellite wrapped into MLI Electronics as close as possible to cold points 2. Propulsion Only half of thruster pre-warmed + duty cycle Only less than half the power is given at the same time (longer pre-warming!) 133

3 PROBA 3 Phase B Power reduction 1. Thermal Control reduced to 75W (instead of 91W) 2. Propulsion reduced to 33,6W (instead of 128W) 3. Payload reduced to 10W (instead of 40W) 134

3 PROBA 3 Phase B Power reduction 1. Thermal Control reduced to 75W (instead of 91W) 2. Propulsion reduced to 33,6W (instead of 128W) 3. Payload reduced to 10W (instead of 40W) What is the next step? 135

3 PROBA 3 Phase B Electrical Architecture 1. Power Generation & Storage Solar Array Battery 2. Power Conditioning Distribution Unit ADPMS 3. Connections Safe & Arm Umbilical Connection 136

3 PROBA 3 Phase B Solar Array Design 1. Main components Cells Series (TBD) String Parallel (TBD) 6xSection (TBD strings) 2. Secondary components Shunt Selection Dump Resistor 137

3 PROBA 3 Phase B Solar Array Design 1. Main components How can we calculate this? Cells Series (TBD) String Parallel (TBD) 6xSection (TBD strings) 2. Secondary components Shunt Selection Dump Resistor 138

3 PROBA 3 Phase B Solar Array Design (3G28%) 1. Evaluate the degradation? Coverglass thickness Degradation of Electrical Parameters Degradation of Temp. Coefficient 139

3 PROBA 3 Phase B Solar Array Design (3G28%) 1. Evaluate the degradation? Coverglass thickness Degradation of Electrical Parameters Degradation of Temp. Coefficient 140

3 PROBA 3 Phase B Solar Array Design 2. Evaluate the number of cells? Max battery voltage to be provided (29.4V) Compute all voltage drop Compute number of cells (MPP) 18 Cells / Strings 141

3 PROBA 3 Phase B Solar Array Design 3. Evaluate the number of strings? Max current allowed by ADPMS (12A) Compute string current EoL ( di/dt < 0) Minimum Solar Cste (di/dc > 0) Operating temperature (di/dt>0 but du/dt<<0) Operating point 142

3 PROBA 3 Phase B Solar Array Design 4. Evaluate the Power available? Power = Current * Voltage 1 String Failure Tolerance 144

3 PROBA 3 Phase B Solar Array Design 4. Evaluate the Power available? Power = Current * Voltage 1 String Failure Tolerance 145

3 PROBA - 3 What if GNC has a failure? 146

3 PROBA - 3 What if GNC has a failure? ANSWER = Needs to be taken into account if pointing accuracy of SUN POINTING is decreased! 147

3 PROBA 3 Phase B Battery Design 1. Main components Cells Series (TBD) String Parallel (TBD) 2. Secondary components Internat heaters Thermistors 148

3 PROBA 3 Phase B Battery Design 1. Main components How can we calculate this? Cells Series (TBD) String Parallel (TBD) 2. Secondary components Internat heaters Thermistors 149

3 PROBA 3 Phase B Battery Design 1. Evaluate the number of cells? Nominal non regulated bus voltage (28V) 7 Cells / String Cells characteristics (4.2V EoC) Cell Level EMF (V) 4.2 4.1 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.1 3.0 2.9 2.8 2.7 2.6 2.5 0 10 20 30 40 50 60 70 80 90 100 State of Charge (%) Discharge EMF Charge EMF 150

3 PROBA 3 Phase B Battery Design 2. Evaluate the number of strings? Approach decision Battery for both Sun & Eclipse Battery for Eclipse only Check Power Budget (Wst Case) Detumbling (200W / 1hr) Eclipse (240W / 30min) Long Eclipse (190W / 3.5hrs) 151

3 PROBA 3 Phase B Battery Design 2. Evaluate the number of strings? Capacity used = Power * Time Capacity required = Capacity Used /(1-DoD Allowed ) Capacity of 1 string = Nb Cells *Capacity Cell One String Failure Tolerance Scenario Used Capacity (Wh) Detumbling 200 Eclipse 120 Long Eclipse 665 Scenario DoD choice Required Capacity (Wh) Detumbling 20% 240 Eclipse 20% 148 Long Eclipse 60% 1064 29 (+1) Strings Parameter Value Nb Cells 7 Capacity Cell 5,4 Wh Capacity 1 string 37,8 Wh 152

3 PROBA 3 Phase B U/D Operational Concept Problems 1. Downlink not closed at apogee at Max Rate 2. Uplink not closed at apogee at Max Rate 3. Data not able to be downlinked below 50kkm at max rate (coverage) 4. Data not able to be downlinked at min rate (coverage) 153

3 PROBA - 3 What can we do? 154

3 PROBA 3 Phase B U/D Operational Concept Solutions 1. Use more power @ Ground Segment 2. Use more power @ Space Segment 3. Use one/several high gain antenna @ Space Segment 4. Use variable data rate Low Rate (Uplink & Downlink) when at apogee High rate (Uplink & Downlink) when at perigee 155

3 PROBA 3 Phase B U/D Operational Concept Solutions 1. Use more power @ Ground Segment What is the consequence? 2. Use more power @ Space Segment 3. Use one/several high gain antenna @ Space Segment 4. Use variable data rate What is the consequence? Low Rate (Uplink & Downlink) when at apogee High rate (Uplink & Downlink) when at perigee 156

3 PROBA - 3 Results! 157

3 PROBA 3 Phase B Updated Configuration 158

3 PROBA 3 Phase B Final Stack Configuration 1. Occulter Spacecraft 2. Coronagraph Spacecraft 159

3 PROBA - 3 How would you now further reduce the cost? 160

3 PROBA - 3 How would you now reduce the cost? ANSWER = Increase the risk! 161

4 CONCLUSION 162

4 CONCLUSION Satellite System Engineering 1. Follows the Project Life Cycle Starts with Mission Concept Prepares System Requirements Proposes System Designs based on Trade-Offs (Technical + Programmatics) Manufacture the S/C Verify Requirements (Review of Design / Analysis / Test) Launch it! 2. Iterative Multi-disciplinary approach + Massive Communication 163

4 OPPORTUNITIES QinetiQ Space 1. Proposes Fast Learning Curve on Satellite Systems 2. Offers possibility to built international network quickly 3. Provides opportunity to be known at the European Space Agency 164

4 OPPORTUNITIES INTERNSHIPS / SUMMER JOB 1. Communication Engineering on PROBA platform (RF & Optical) 165

4 OPPORTUNITIES INTERNSHIPS / SUMMER JOB 1. Communication Engineering on PROBA platform (RF & Optical) Constellation Communication Strategy (Tasking & Data reception) Detailed simulations on commanding and control (duty cycles) Communication Subsystem Sizing & Design Integration of Optical COM into RF architecture 166