From a phone call to a satellite orbiting Earth Xavier Werner Space Structures and Systems Lab. Aerospace & Mechanical Engineering Dept. University of Liège
My background 2011: HELMo Gramme, Industrial engineer (electronics) 2011-2014: ULg, OUFTI-1 team member (COMM and payload) 2014-2016: ULg, Project Manager for OUFTI-1 2016- : ULg S3L, Research Engineer: nanosatellite design 2
Outline 1. Objectives 2. Space Segment 1. Payloads 2. Orbit and mission analysis 3. Platform 4. Protoflight model 3. Ground segment 4. What s next? 3
1. Objectives Decrease size, Increase interactions! 4
1. Objectives Primary Goal Hands-on satellite experience for students 5
1. Objectives Primary Goal Hands-on satellite experience for students Long-term Goal Series of CubeSats for scientific experiments Formation flying Granular materials 6
1. Objectives Primary Goal Hands-on satellite experience for students Long-term Goal Series of CubeSats for scientific experiments Short-term Goal Orbital Utility For Telecommunication Innovation 7
Outline 1. Objectives 2. Space Segment 1. Payloads 2. Orbit and mission analysis 3. Platform 4. Protoflight model 3. Ground segment 4. Unique experience for students 5. What s next? 8
2.1 Payloads D-STAR Digital-Smart Technology for Amateur Radio Simultaneous data and voice digital transmission Complete routing capacity, including roaming 3 frequencies and 2 data rates - VHF: 144 MHz (2m) 4.8 kbit/sec - UHF: 435 MHz (70cm) 4.8 kbit/sec - SHF: 1.2 GHz (23cm) 4.8 kbit/sec or 128kbit/sec Data : 1200 bps - Voice : 3600 bps Open protocol (! AMBE) GMSK modulation 9
2.1 Payloads D-STAR 3 types of communications: Direct visibility 10
2.1 Payloads D-STAR 3 types of communications: Repeater zone 11
2.1 Payloads D-STAR 3 types of communications: Internet roaming 12
2.1 Payloads D-STAR Directly through OUFTI-1 13
2.1 Payloads D-STAR Through OUFTI-1 and internet A Extension SAT Relais D-STAR Internet Relais D-STAR B 14
2.1 Payloads solar cells High-performance solar cells (30% GaAs triple junction) 15
Payloads More and more applications! Technology demonstration ( ) Imaging Communications Earth remote sensing Biology Re-entry Debris removal Security (AIS, ADS-B ) 16
Outline 1. Objectives 2. Space Segment 1. Payloads 2. Orbit and mission analysis 3. Platform 4. Protoflight model 3. Ground segment 4. Unique experience for students 5. What s next? 17
2.2 Orbit and mission analysis CubeSats = secondary payloads Orbit imposed by primary payload Mission analysis = Analyze impact of this imposed orbit designed for Vega maiden flight 1447 x 354 km, i = 71 Very demanding! But finally: Soyuz VS14 437 x 683 km, i = 98 More comfortable! 18
2.2 Orbit and mission analysis 19
2.2 Orbit and mission analysis 20
2.2 Orbit and mission analysis 21
Outline 1. Objectives 2. Space Segment 1. Payloads 2. Orbit and mission analysis 3. Platform 4. Protoflight model 3. Ground segment 4. What s next? 22
2.3 Platform 23
2.3 Platform ADCS: requirements Payloads: no specific pointing requirement COMM: max 10 /s (avoid signal modulation) Mass, volume, and power constraints Passive control is sufficient! 24
2.3 Platform ADCS: passive magnetic A permanent magnet interacts with the geomagnetic field, producing a restoring torque, which align satellite axis with Earth s magnetic field. The spacecraft will oscillate around energy minima The oscillation are damped out by hysteretic rods. 25
2.3 Platform ADCS: orientation 26
2.3 Platform ADCS: final design 27
2.3 Platform ADCS: flight model 28
Surrey Space Center + Stellenbosch University Blue Canyon Technology ADCS State of the Art Actuators: - Magnetorquers - Reaction wheels Sensors: - Magnetometers - Star trackers - Sun/Earth sensors - Gyroscopes Pointing accuracy < 1 + propulsion (cold gas thrusters, pulsed plasma thrusters) 29
2.3 Platform COMM: requirements ITU: 30
2.3 Platform COMM: IARU All links must be located within the agreed ham band specific space allocations Coordination process 31
2.3 Platform COMM: frequency bands Uplink: 70-cm band (435 MHz, UHF) Downlink: 2-m band (145 MHz, VHF) 32
2.3 Platform COMM: 3 channels Payload: D-STAR (GMSK, 4800 bauds) TC/TM: AX.25 telecommunication protocol: simple and standard within the ham community 2FSK, 9600 bauds. Beacon: extreme reliability (Morse code). 33
2.3 Platform COMM: AX.25 frame 01111110 Start and end of frame 34
2.3 Platform COMM: AX.25 frame Source and destination 35
2.3 Platform COMM: AX.25 frame Type of frame (unnumbered) Link integrity 36
2.3 Platform COMM: AX.25 frame Protocol Identification (network) OUFTI-1 : 11110000 37
2.3 Platform COMM: AX.25 frame Useful information 38
2.3 Platform COMM: AX.25 frame Checksum Error detection 39
2.3 Platform COMM: TC/TM General Model OUFTI-1 Application Presentation Session Transport Network Application Transport PUS CCSDS Data link Data link AX.25 Physical Physical RF & Modulation 40
2.3 Platform COMM: TM/TC 41
2.3 Platform COMM: block diagram RX: 435 MHz TX: 145 MHz RF D-STAR AX.25 ADF 7021 Demod D-STAR Zone 1 et 2 ADF 7021 Demod AX.25 MSP430 Codec D-STAR Data MSP430 OBC TC/TM Processing ADF 7021 Modulation AX.25 / D-STAR RF BEACON 42
2.3 Platform COMM: low-gain antennas Two monopole (quarter-wave) antennas : 17 and 50 cm 43
2.3 Platform COMM: low-gain antennas Two monopole (quarter-wave) antennas : 17 and 50 cm Too short! (non-radiating parts) Re-dimensionning Impact on MECH 44
2.3 Platform COMM: propagation 45
2.3 Platform COMM: prototypes 46
2.3 Platform COMM: flight model 47
COMM: State of the art Mainly VHF & UHF S-band more and more used X-band (COTS available) Limitations: licensing, power, ground segment Inter-satellites link ISIS 48
COMM: State of the art 49
2.3 Platform EPS: requirements Defined by other subsystems Power needed by client Voltage required by hardware Influenced by orbit Eclipse duration Influenced by the mission Payload operation Power budget 50
2.3 Platform EPS: block diagram Power Source Power Storage Unit Power Conditioning Unit Users 51
2.3 Platform EPS: solar cells GaInP/GaAs/Ge on Ge substrate Triple junction solar cells At 28ºC 52
2.3 Platform EPS: solar arrays 53
2.3 Platform EPS: 2 Kokam batteries Kokam SLB 603870H 54
2.3 Platform EPS: batteries test 55
2.3 Platform EPS: batteries support 56
2.3 Platform EPS: conditioning Direct energy transfer Choice of unregulated bus with three DC/DC converters: 5 V redundant 3,3 V Design validated by Thales Alenia Space ETCA 57
2.3 Platform EPS: engineering model MECH circuit MHP protection MHP ( T, V, I ) Dissipation system Battery-charger module Solar cells protection Battery protection module 5V 3,3 V (A) 3,3 V (B) 58
2.3 Platform EPS: flight model 59
EPS: State of the art Triple junction solar cells (28-30 % efficiency) Li-Ion batteries (200 Wh/kg) MPPT: Maximum Power Point Tracking 60
2.3 Platform MECH: requirements CubeSat Design Specification: 2.4.2. All deployables such as booms, antennas, and solar panels shall wait to deploy a minimum of 30 minutes after the CubeSat s deployment switch(es) are activated from P-POD ejection. Antennas are wound around a guide before deployement Dyneema retention wire is used Retention wire is melted by a thermal knife 61
2.3 Platform MECH: flight model ULg JL Wertz 62
Credit: Alessandra Babuscia Antenna State of the art Mostly burned wire and spring material Patch antennas for higher frequencies (S, X) Inflatable devices under development 63
2.3 Platform OBC: hardware Reliability and simplicity One central processor, handles all tasks Doubled for redundancy: only one active at a time Periodic «heartbeat» signal Texas Instruments MSP430 I/Os 64
2.3 Platform OBC: software 65
2.3 Platform STRU: launch environment 66
2.3 Platform STRU: requirements accelerations, low frequencies 67
2.3 Platform STRU: requirements Engines, wind ; high frequencies 68
2.3 Platform STRU: requirements Engines, turbulences Fairing jettison, stages separation 69
2.3 Platform STRU: models vs reality 70
2.3 Platform STRU: models vs reality Modes 1 & 2 71
2.3 Platform STRU: electronic cards 72
STRU State of the art Aluminum COTS or homemade structures, very similar Coming: composites, 3D printed 73
2.3 Platform THER: requirements 74
2.3 Platform THER: hot and colds cases 75
2.3 Platform THER: measurements Determination of the frame contact resistance: face 6 is heated up Face 1 Face 3 76
2.3 Platform THER: measurements 77
2.3 Platform THER: analysis (cold) Battery is too cold! 78
2.3 Platform THER: analysis (hot) 79
2.3 Platform THER: analysis (hot) Hot spot due to dissipation transistor! 80
2.3 Platform THER: thermal control The available surface on the satellite panels is very limited. Difficult to control the overall energy balance between the spacecraft and its environment. 81
2.3 Platform THER: conductive links Thermal control can be achieved by an appropriate study and design of the conductive links within the satellite. Copper angle bracket 82
2.3 Platform THER: conductive links 83
2.3 Platform THER: batteries issue 84
2.3 Platform THER: active control Heaters + Thermostats 1 heater per battery 2 x 250mW patch heaters 26.3 59.4 x 35.6 mm Mechanical thermostats 2 thermostats per battery, in series 7.2 C 23.9 C 85
2.3 Platform THER: tests POM spacers 86
THER State of the art Passive means (MLI, coating) Heaters for sensitive equipment 87
2.3 Platform Configuration UHF antenna Thermal knives VHF antenna Pumpkin structure Solar cells COMM Beacon Batteries EPS MAIN OBC BACKUP OBC (FM430) 88
Outline 1. Objectives 2. Space Segment 1. Payloads 2. Orbit and mission analysis 3. Platform 4. Protoflight model 3. Ground segment 4. What s next? 89
2.4 Protoflight model: philosophy Engineering model qualification tests + Flight model acceptance tests + Space Protoflight model protoflight tests + Space (= qualification levels with acceptance duration) 90
2.4 Protoflight model
2.4 Protoflight model Write, test, and correct integration procedures Perform integration at Centre Spatial de Liège (CSL) of ULg
2.4 Protoflight model: TVC Tests at ESA/ESTEC thanks to ESA Fly Your Satellite! program ESA 93
2.4 Protoflight model: TVC 94
2.4 Protoflight model: vibration tests Tests at ESA/ESTEC thanks to ESA Fly Your Satellite! program 95
2.4 Protoflight model: vibration tests
2.4 Protoflight model: vibration tests 97
2.4 Protoflight model: X-rays EM X-rays at ESA/ESTEC thanks to ESA Fly Your Satellite! program FM 98
2.4 Protoflight model: ready for launch! 99
2.4 Protoflight model: P-POD integration 100
2.4 Protoflight model: on ASAP-S 101
2.4 Protoflight model: Launched! Soyuz Flight VS14 Centre Spatial Guyanais, Kourou 25 April 2016 102
2.4 Protoflight model: signal received > 500 Beacon messages received from HAM operators 103
Outline 1. Objectives 2. Space Segment 1. Payloads 2. Orbit and mission analysis 3. Platform 4. Protoflight model 3. Ground segment 4. What s next? 104
3. Ground segment TC / TM channel (AX.25) User channel (D-STAR) Mission Control Center Ground Station 12:05:49 TCP / IP Satellite Extension D-Star Repeater Control segment D-STAR segment 105
3. Ground segment UHF Antenna VHF Antenna el az H V H V Rotators controller Phasing line Phasing line FM UHF FM VHF Tracking card CI-V UHF/VHF Transceiver 12:05:49 Pointing data Control AX.25 Mission Control Center TCP / IP Serial Data GS computer Ground Station TNC 106
3. Ground segment OUFTI-1 Duplexer Duplexer Tracking System Tx Rx Tx Rx VHF module UHF module UHF/VHF Transceiver Controller D-STAR mod/demod Gateway Internet D-Star Repeater Satellite extension 107
Outline 1. Objectives 2. Space Segment 1. Payloads 2. Orbit and mission analysis 3. Platform 4. Protoflight model 3. Ground segment 4. What s next? 108
4. What s next? OUFTI-2 1U CubeSat Design improvements based on experience 3 payloads: D-STAR (OUFTI-1 mission) RAD IMU (Sint Pieterscollege Jette, Belgium) 109
4. What s next? OUFTI-2 Main payload: D-STAR Digital Smart Technologies for Amateur Radio Digital radio protocol 2 modes : DV (Digital Voice) : Voice + data (145MHz, 435MHz et 1.2GHz) DD (Digital Data) : Data only (1.2GHz) 2 A Extension SAT Relais D-STAR Internet Relais D-STAR B 110
4. What s next? OUFTI-2 Secondary payload: RAD Degradation of electronical components by radiations Same experience 3 different shieldings Dose measured by a RADFET 111
4. What s next? OUFTI-2 Secondary payload: IMU Developed by secondary school students Free access to space thanks to OUFTI-2 112
4. What s next? OUFTI-2 Platform improvements On-Board Computer COMM Beacon Structure EPS 113
4. What s next? Earth observation Innovation in space with ULg Scientific and technological demonstrations in an educational frame Currently designing a new Earth observation mission Define potential applications Define satellite (payload and platform) Build first model 114
Thank you for your attention 115