YamSat Introduction

YamSat TeamAlbert Lin (NSPO)

YamSat

Yamsat website http://www.nspo.gov.tw

YamSatYamSat Major Characteristics

• Mission:– Y: ‘Young’, developed by young people. – A: Amateur Radio Communication– M: Micro-spectrometer payload with Micro Electro Mechanical Systems (MEMS) technology

• Orbit: (TBD)• Launch Vehicle: the Dnepr from the Russian launch site at Baikonour.• Target Launch Time: Fall 2004 (TBD)• Mass: within 1kg, Volume: 10cm*10cm*10cm• Mission Life: 1 month ; Design Life: 2 months• Power: multi-junction GaAs solar cells, and Si solar cells, surface mounted; rechargeable

battery; secondary voltage 5V• Amateur Radio Communication: Uplink/Downlink-145.85MHz , Data Rate: 1200bps, half

duplex, FSK; CW downlink frequency 29.355MHz, Morse code, 70 characters/min.• On-Board Computer: 80C52 micro-controller, 32K bytes external RAM• Attitude Determination & Control: B-dot control with a magnetometer and magnetic coils • Passive thermal control• Structure: Aluminum

YamSatYamSat Development Schedule

Main ActivitiesMain Activities Start ~ EndStart ~ End PeriodPeriod

1. Working Start Date (WSD)1. Working Start Date (WSD) 2001/03/292001/03/29

2. Mission Analysis and System Design2. Mission Analysis and System Design 2001/04~052001/04~05 2 months2 months

3. System Design Review (SDR)3. System Design Review (SDR) 2001/05/282001/05/28

4. Preliminary Design4. Preliminary Design 2001/06~072001/06~07 2 months2 months

5. Preliminary Design Review (PDR)5. Preliminary Design Review (PDR) 2001/07/242001/07/24

6. Critical Design6. Critical Design 2001/08~092001/08~09 2 months2 months

7. Critical Design Review (CDR)7. Critical Design Review (CDR) 2001/09/272001/09/27

8. Flight HW Manufacture and Assembly8. Flight HW Manufacture and Assembly 2001/10~122001/10~12 3 months3 months

9. Test Readiness Review (TRR)9. Test Readiness Review (TRR) 2002/01/152002/01/15

10. Satellite Environmental Testing10. Satellite Environmental Testing 2002/01~032002/01~03 3 months3 months

Total PeriodTotal Period 1 year1 year

YamSat

+Y Panel•Battery•Magnetic Coil

-X Panel•Magnetometer•Magnetic Coil•CW Antenna x 1

-Z Panel•TT&C•Antenna x 1

+X Panel•Payload_Micro-Spectrometer•CW Antenna x 1

-Y Panel•OBMU

+Z Panel•DRU•Antenna x 1

XY

Z

Satellite Structure ConfigurationSatellite Structure Configuration

YamSatElectrical Block Diagram

Micro-Controller

80C52

D/AConverter

OPAmp.

MagneticCoil #1, #2

A/DConverter

OPAmp.

3-axisMagneto-

meter

CW Generator

FSKModulator

FSKDemodulatorReceiver

Transmitter

DiplexerCoupler

BatteryBattery

Micro-Spectrometer

RAM32KBytes

Solar Array

...

x 6Solar Array

...

x 6

DC/DCConverter

PowerDistribution

PowerMonitor& WDT

TemperatureSensor

CurrentTelemetry

VoltageTelemetry

BilevelOutput

BilevelInput

FiberCoupler

3.75V+5V, -5V

To Units

Rx

Rx

Bi

145.85MHz

145.85MHz

29.355MHz

BiCoupler

YamSat

t

FOV

t

Payload: Micro-Spectrometer

By PIDC

• Study the atmosphere elements by measuring the sunlight scattering spectrum from the atmosphere. The measurement characteristics of the micro-spectrometer payload are: detection spectrum range 380nm ~ 780 nm, 256 bands, 12 nm resolution per band.

• Study the atmosphere condition from the unusual albedo value, e.g. volcanic aerosol using micro-spectrometer by measuring the solar energy reflected from the Earth (Albedo).

• In addition, user can also study the Ionosphere’s effect on RF wave propagation, specially for 29MHz.

YamSatMicro-Spectrometer Block Diagram

By PIDC

102/122 Quartz-Quartz Fiber

CMOS Detector256 Pixels

MEMS DiffractionDevice

LED Pre-Amplifier

A/D

Single ChipMicro-Controller

BUS/Payload InterfacePower Line/ 5V

F#2Quartz Lens

Clock/Driving Line 8 Bits Serial Signal

Optical Subsystem Electronic Circuit

259 Bytes/1.172sec2400 bps

YamSatIrradiance Calibration System Diagram

Integration Sphere

Monochromator

MEMS DiffractionDevice

Standard DetectorLens

Fiber

MicroSpectrometer

RS232

Power Supply

5V/DC

Power Meter

MicroSpectrometer:

LED: LED

Power Meter

Spectrometer

Power Supply and Monitoring

……….

380 780

YamSatYamsat Stress Distribution

YamSat

ADCS Subsystem Design- Control System Block Diagram

Environmental

Disturbance

S/C DynamicsMagnetic Coil

H/W ModelB-dot Control Law

2nd Order

Low-pass Filter

Earth’s

Magnetic FieldB : Magnetic Flux Density

B (Filtered)

Implemented by Flight Software

ADCS Hardware (Magnetic Coils)

ADCS Hardware (Magnetometer)

1. Q : Attitude

2.

: Angular Rate

M : Magnetic Moment

Td : Disturbance Torque

P : S/C position

Eclipse limit sunlight

ZX

ZX

Z- YX

ZX

ZX

Z X

Z X

ZX

ZX

Z- YX

ZX

YamSatFSW Executive Loop – Flow Diagrams

Reset Initialization

Command ISR

PayloadData ISR

Executive Loop

Executive LoopInitialization

Timer ISR

CMD Reception

Task

CMDProcessing

Task

P/L DataReception

Task

P/L DataStorage

Task

Actuator Output

Task

TelemetryPacket

Task

ADCSTask

EPSTask

TelemetryTransmit

Task

SensorInputTask

BackgroundBuilt-in

Task

CRCChecking

Task

CMDexecution

Task

YamSatYamSat 1A & 1B

Items YamSat-1A YamSat-1B Purpose Final Flight Backup; Demonstration;

Fit Check Solar Panel with Cells 1 Si +5 GaAs 6 Si Battery E-ONE ICR 18500A Panasonic P-150S Low Battery Voltage Cutoff Circuit

For ICR 18500A For P-150S

CW Antenna Wires with Teflon coating, and metal supporters. (better protection)

Wires with enamel coating

Mass 867g 843g Others Same Same

YamSatThermal Cycling Test

By NSPO

YamSatThermal Vacuum Test

Test Condition: YamSat-1A is under 5x10-7mbar vacuum condition.

By PIDC

YamSatYamSat 1-A/B Vibration Test

Test Condition: YamSat is installed in Test P-POD

Sine Sweep Test: freq range: 1600 Hz,Sweep rate: 2 oct/min, Test level: 0.2g

– Sine Burst: Test freq : 20 Hz Test cycle: 40 cycles, Test level: 10.25g

– Random Vibration

By NSPO

YamSatGround Systems to YamSat End-to-End Test

One amateur ground station uses two YAGI antennas for VHF communication with 12dBi-antenna gain and 100W-transmitter power to receive both YamSat telemetry and Morse code signal sent from the amateur communication payload.

Continuous wave (CW) circuit generates tracking beacon and SOH data under the control of the on-board controller.

The Call sign of the ground station is “BN0SPO” and the call sign of the YamSat is “BN01A”.

By NSPO

YamSatFrequency Coordination

YamSat Call Sign: BN01A

YamSatBatteries Capacity Test

The YamSat-1A Flight Battery capacity was retested on 2004/3/4. – Charge Condition: maximum charge current is 1 Amp., maximum charge voltage is

4.2V– Discharge Condition: fixed discharge current 0.28 Amp., end of discharge voltage

is 2.5V– YamSat-1A Flight Battery capacity is 3.6 Amp-Hour.

YamSat Battery Discharge Curve

0

1

2

3

4

1 3601 7201 10801 14401 18001 21601Discharge Time (Sec)

Battery VoltageDischarge Current (A)Discharge Capacity (AH)

YamSat Battery Charge Curve

0

1

2

3

4

5

1 3601 7201 10801 14401 18001

Time (Sec)

Battery Voltage (V)

Charge Current (A)

Battery Charge Capacity (AH)

YamSatYamSat-1A RF Pattern - VHF

Retest YamSat-1A RF patterns in NSPO Anechoic Chamber on 2004/03/24. The test distance is 9.28m.

YamSa-1A with flight battery, 0 deg orientation,VHF pattern

YamSa-1A with flight battery, rotation,VHF pattern

YamSatYamSat-1A RF Pattern - HF

YamSa-1A with flight battery, 0 deg orientation,HF pattern

YamSa-1A with flight battery, rotation,HF pattern with Morse codes

YamSatInvolved Domestic Organizations

Rechargeable Battery

台翔航太工業股份有限公司 : Structure Manufacture

: Attitude Analysis

: Space Science Research

Electrical Board Soldering

: Micro-controller & RAM

: Solar Array Assembly

: Amateur Radio League

Antenna Deployment, Ground Station

System Integration, Subsystem Design, I&T, Flight Operation

PIDC: Micro-Spectrometer