TIsat-1 SUPSI 8d“Old wise saying” ... Li-Ion (SAFT) and LiPo batteries Automated tests for thermal/charge-discharge cycles, lab. vacuum underway. 29/05/2008 21 Dipartimento Tecnologie

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DipartimentoTecnologieInnovative

Scuola Universitaria Professionaledella Svizzera Italiana

SUPSI

SpaceLab

SUPSI SUPSI -- SpaceLabSpaceLab

TIsatTIsat--11

ESAESA--ESTEC ESTEC CubeSatCubeSat WorkshopWorkshop2222--24 January 2008, 24 January 2008, NoordwijkNoordwijk, the Netherlands, the Netherlands

I. Bonesana, P. Ceppi, S. I. Bonesana, P. Ceppi, S. PuseljicPuseljic, A. Weston , A. Weston

29/05/2008 3



SUPSI Presentation OutlinePresentation Outline

� SUPSI – the Institution

� SUPSI-SpaceLab� Inception – Go – Student Involvement

� Project Organization� TIsat-1, our first student spacecraft

� Subsystems� Test Equipment

� Ground Station� Status and Open Questions

2

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SUPSI The 7 Swiss UASThe 7 Swiss UAS

San Gallo Zurigo

Lucerna

Berna

Lugano

Basilea Delémont

Losanna

Ginevra Sion

BFH

HES-SO

FHZ

FHO

ZFHFHNW

SUPSI

Scuola UniversitariaProfessionale dellaSvizzera Italiana

FachhochschuleOstschweiz

ZürcherFachhochschule

FachhochschuleNordwestschweiz

BernerFachhochschule

FachhochschuleZentralschweiz

Haute ÉcoleSpécialisée de Suisse Occidentale 2000

students

6000students

10000students

3000students

5500students

3000students

10500students

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SUPSI Study RoadmapStudy Roadmap

UniversityFederal Institute

of Technology

(Bachelor + Master: 5 yrs)(Bachelor: 3 yrs)

Vocational Schools (4 yrs)

High School (4 yrs)

Diploma Diploma

Mandatory School (9 yrs)

Prof. ExperienceExamination

(Master: 1.5 yrs)

3

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SUPSI Studies and ECTSStudies and ECTS

� Schools from age 6 to age 18

� University� Bachelors 3 years (full time): 180 ECTS� Masters 1.5/2 years (full time): 90-120 ECTS

� Credits� 1 ECTS = 25-30 hours lessons + study� 1 semester = 30 ECTS

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SUPSI

The Inception of Space @ SUPSIThe Inception of Space @ SUPSI

� September 2004� First internal report: “Space Mission Lab”, based

on Information from - and talks with� ESA Edu Office and SSETI� Swiss Space Office� Bob Twiggs, Stanford CA, USA

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SUPSI Second StepSecond Step

� February 2005� Go, see and talk to people

Moffett Field – Stanford, Ca US

Bob Twiggs, a wonderful hostat Moffett Field – Stanford, Ca US

Jordi P. Suari and his studentsat CalPoly – S. Luis Obispo, Ca US

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SUPSI End of 2005End of 2005……

� Counting on its engineering curricula in� Computer sciences

� Electronics � Machine technologies

� In spite of no in house space expertise,� With some bravery and ambition for its students

SUPSI approves the start up of SpaceLab.

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SUPSI Why SpaceWhy Space

� To promote the interest in science and technology studies, leveraging the fascination of space endeavours.

� To raise a space-aware young engineer generation ready for involvement in real scientific space projects.

«The most important “payload” is not what you launch, but what safely remains on the ground»

“Old wise saying”

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SUPSI By the End of 2007By the End of 2007

� Regular Curriculum Activities

� 6 Laboratories� 15 projects� 21 students

� 25 Semester Projects� 50 students

� 11 Diploma Projects� 11 students

� http://www.spacelab.dti.supsi.ch/tiSat1Lab.html

Total51 projects82 students

6

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SUPSI SSL Volunteering TeamSSL Volunteering Team

� 9 junior students (1st, 2nd year)� 3 advanced students (3rd year)� 10+ Professors, Lecturers and Partners

TotalOctober 200722 volunteers

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SUPSI International ContextInternational Context

� Sponsoring for 3 SpaceLab students to participate to

CubeSatCubeSat WorkshopWorkshop&&

SmallSatSmallSat ConferenceConference

Logan, Utah, USALogan, Utah, USA77--17 August 200717 August 2007

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SUPSI Project OrganizationProject Organization

Team Professors

SpaceLabDirection

Assistants

Dept. Professors

StudentProjects

Laboratories SemesterProjects

BSc Projects

SpaceLabTeam

VolunteeringStudents

Academic and Industrial Partners

Ham Community

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SUPSI Analysis ProcessAnalysis Process

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SUPSI Facts and ParametersFacts and Parameters

� Facts� Development manageable mostly by students� Our very first, so “Keep It Simple S…!”

� Parameters� Mission lifespan: 2 months� Orbit: LEO, circular, polar, sun-synchronous

(up to this Workshop… Vega?)

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SUPSI Space SegmentSpace Segment

� TIsat-1: named by the home state of our University: Ticino (TI)

� Complying with CubeSat standard� Subsystems

� SMM: Structures, Mechanics and Materials� EPS: Electric Power System� COMM: Communication� OBC/CDH: On Board Computer(s)� ADCS: Attitude Determination and

Control System� TC: Thermal Control

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SUPSI SMMSMM

� Custom Design� ICIMSI - SUPSI� RUAG Aerospace, Lodrino

� Standard 1U Structure from Stanford/CalPoly

� Screws only on +Z/-Z faces

� Faces may be mounted “face-in” or “face-out”� additional 6.5mm from the s/c

wall to the P-Pod

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SUPSI SMMSMM

� Testing how subsystems fit (demo mock-up)� Test assembly

and disassembly procedure

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SUPSI EPS EPS –– Batteries TestBatteries Test

� Charge batteries directly from PV-array.� Manage consumption according to energy

availability.� Protect against overcharge / deep discharge and

operate only at allowed temperatures.� PV-arrays

� Custom cut PV-cells c-Si, Solterra S.A.: allows for selection of voltage (16%, AM1.5)

� Standard format PV-cells, single-junction GaAs, CESI (20%, AM0), space proven

� Latchup (SEL):� EPS electronics is bipolar – less prone to SEL than

CMOS?!� Subsystems protected by dedicated current

monitoring and break circuits

� Regulated busses: 3.3V and 6V� Li-Ion (SAFT) and LiPo batteries� Automated tests for thermal/charge-discharge

cycles, lab. vacuum underway.

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SUPSI EPS EPS –– Batteries TestBatteries Test

3.6

3.7

3.8

3.9

4

4.1

4.2

4.3

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300

Time [x*5s]

Vol

tage

[V]

Charge @ 20°C Charge @ 10°C Charge @ 0°C Charge @ -10°C

Charge

1A

0.5A

0.25A

3.1

3.2

3.3

3.4

3.5

3.6

3.7

3.8

3.9

4

0 100 200 300 400 500 600 700 800 900 1000 1100

Time [x*5s]

Vol

tage

[V]

Discharge @ 20°C Discharge @ 10°C Discharge @ 0°C Discharge @ -10°C

Discharge1A

0.5A

0.25A

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SUPSI EPS EPS –– Solar CellsSolar Cells

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SUPSI COMMCOMM

� Concept� Not building from scratch, i.e. Commercial Subsystem Integration� Ham Bands: 144 and 430MHz� Beacon on 430MHz has priority over other TX operations� Antennas: simple scheme, mono- and dipole antennas

� Done� Selection and Test of Transceivers: focusing on Alinco and

Chipcon (CC1010)� Firmware: Morse, PPM, FSK, PSK, DTMF, Manchester,

Correlation for MSP430 and PIC

� To do� Link budget details.� Communication Channel Request (IARU?)

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SUPSI COMM COMM –– Demodulator Demodulator

// LP filter C// Fourier_c= LP_K *Fourier_c+ LP_K_1 * c_old;

Fourier_c= (Fourier_c >>6)+((c_old * 63)>>6);c_old = Fourier_c;

Fourier_c= (Fourier_c >>3)+((c_old*7)>>3);c_old = Fourier_c;

//attenuationif(c_level_min>Fourier_c)

c_level_min = Fourier_c;

if(Fourier_c>c_level_max)c_level_max = Fourier_c;

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SUPSI COMM COMM –– RadioRadio

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SUPSI OBCOBC

� Redundancy� doubled µC boards, 2 different HW� relaying each other every minute (turn off / turn on)

� MSP430, PIC16LF, PIC18LF, SD-Flash (multiple units), FRAM� Internal communication: I2C

PICMSP

Control Bus I 2C

Debug Programming

Debug / Programming

HWWDT

HWWDT

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SUPSI OBC OBC –– Thermal TestThermal Test

� Thermal test with µC running on internal and external oscillators� Checksum of the program flash, Measure ADC, Frequency of TogglingPin,

Serial communication� MSP430F169 (spec -40 … +85degC)

� up to +120degC – No errors� to 130degC – sporadic errors (unpredictable jumps in memory)� restarts regular operation after HW reset @120degC

� PIC18LF8722 (spec -40 … +120degC)� up to +190degC – No errors

LFTX1CLK 46 0xE244 124.2 C 1.7 1.6 1.6 1.6 1. 6 1.6 1.6 1.6

DCOCLK 47 0xE244 121.5 C 1.6 1.6 1.6 1.6 1.6 1. 6 1.6 1.6

LFTX1CLK 48 0xE244 125.4 C 1.6 1.6 1.6 1.6 1.6 1. 6 1.6 1.6

DCOCLK 49 0xE244 132.7 C 1.6 1.6 1.6 1.6 1.6 1. 6 1.6 1.7

ŒFTX1�LK 0xB2FA 121.5 C ±.6 1.6 1®¶ ° 1.6 1.6 1.6 € 1.6 1.6

DCOCLK Šþ0xEF72 113.1 C 1® 1.¶ 1.6 1.6 1.6 ±É Šr²Šr²R

LFTX1CLK 50

LFTX1CLK 0x84F5 99.5 C 1.6 .0 1.6 1. 6 1.6 1.6 1.6 1.6

DCOCLK1 1 0xE244 121.5 C 1.6 1.6 1.6 1.6 1.6 1. 6 1.6 1.6

Temperature Regular operaton Error

HW Reset

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SUPSI ADCSADCS

� For TIsat-1:� Passive, permanent magnet orientation

along Earth’s magnetic field lines � Libration damping: mumetall, hysteresis

plate

� Student projects on ADCS� Magnetorquer� Momentum wheel� Pulsed Plasma Thruster� Levitron (>2kg, vertical axis free rotation)

Magnetic Field

Dipole Moment

Antennae

Ground Station

(XI-V doc)

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SUPSI ADCS ADCS –– Lab ExperimentsLab Experiments

LevitronMomentum WheelPulsed Plasma Thruster

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SUPSI ADCS ADCS –– Lab ExperimentsLab Experiments

Experimental setup tocharacterize the PPT

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SUPSI TCTC

� No active Thermal Control is foreseen for TIsat-1

� TIsat-1 will rotate about its magnetic orientation axis limiting temperature differences in the S/C structure

� Expected temperature: -40 … +80degC (data for body mounted solar generator from bibliography)

� Temperature will be an issue mainly for batteries

� Those who put batteries along the walls arguing they will help shielding against radiation…

� Those who put batteries at the center of mass, arguing there will be a thermal advantage…� Models? Suggestions?

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SUPSI Ground StationGround Station

� Local and remote station (mountain site)� Secured remote access via web

(public/private area)� Queuing of tracking requests� Automatic TLE retrieval and update from

Space-Track (running project)� Automatic antenna pointing � Ham radio support

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SUPSI Status and Open QuestionsStatus and Open Questions

� Subsystems undergo detailed tests

� Antennas and communication schemes need additional effort

� Integration and system level testing ahead� ASAP: Link channel request/coordination

� Acceptance tests: who, where?� Ev. Changes to comply with Vega parameters?� GENSO?

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SUPSI Partners and SponsorsPartners and Sponsors

� RUAG Aerospace, Lodrino (CH)� Solterra SA, Chiasso (CH)� Cadsoft GmbH (D)� CESI: Centro Elettrotecnico Sperimentale Italiano, Milano (I)� Minimotor SA, Croglio (CH)� Metallux SA, Mendrisio (CH)� Geomag SA, Rancate (CH)� Hotline SA, Chiasso (CH); Yaesu (JP)� NXP-Philips Semiconductors

� Fondazione R. Chaudoire, Lugano (CH)� Fidinam SA, Lugano (CH)� HB9MAD, HB9AUS, HB9CHN, et. al.

� AMSAT – SBS, San Bernardino (CH)

� Divisione della Formazione Professionale, DECS (CH)

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SUPSI

Thank you

for your attention

Documents

TIsat-1 SUPSI 8d“Old wise saying” ... Li-Ion (SAFT) and LiPo batteries Automated tests for thermal/charge-discharge cycles, lab. vacuum underway. 29/05/2008 21 Dipartimento Tecnologie