Slide 1

PROBAProject for On-board Autonomy

Verhaert Design and Development nv

Hogenakkerhoekstraat 9

B 9150 Kruibeke

Tel. 03/250.19.37 Fax 03/254.10.08

e-mail : jo.bermyn@verhaert.com

www.verhaert.com

European Space Agency

Directorate of Technology and Operations

ESTEC

The Netherlands

e-mail : fteston @etsec.esa.nl

October 2000 Slide 2

PROBA Introduction

PRoject for On Board Autonomy

October 2000 Slide 3

PROBA: Project Organisation

• Customer: ESA• Prime Contractor: Verhaert Design &

Development (BE)• Subcontractors: Spacebel (BE), Space

Application Services (BE), Space Systems Finland (Fi), SIL (UK), Universite de Sherbrooke (Can), Officine Galileo (It)

• Suppliers

October 2000 Slide 4

Proba : Mission

• ESA technology demonstration program• Operational Autonomy demonstration

– Planning-scheduling, resource management, FDIR, On-board Flight Dynamics

• New Technology Demonstration– Powerfull avionics system, ERC32 and DSP, Li-Ion Battery, 3D

Package Technology, GPS Attitude Determination

• Payload Demonstration– Main instrument (CHRIS) challenging the autonomy and ACNS– SREM, DEBIE, HRC, WAC

• Internet Access

October 2000 Slide 5

Proba : Key figures

• Mass : 100 kg

• Volume : 80cm x 60cm x 60cm

• Power : 40 to 90 W

• Compatible with PSLV / ASAP5

• High pointing accuracy ACNS– Absolute pointing error 150 arcsec– Relative pointing error 5 arcsec over 10 sec

October 2000 Slide 6

PROBA Block Diagram

DHS

AOCS I/F

Reaction Wheels (4)

Magnetometers (2)

Magnetotorquers (4)

PCS

GPS Receiver

Star Tracker (2)

Head

Head

Receivers (2)Transmitters

(2)

SREM

DEBIE

PPU

CHRIS

Imagers

Other Payloads

BatterySolar Array

Power line

Digital Control line

October 2000 Slide 7

PROBA Subsystems

• Honeycomb structure• Passive thermal control• Body mounted solar panels

with GaAs cells• 28 V regulated power bus, 9

Ah Lithium-Ion battery• S-band communication

system ( 4kbit/s uplink, 1Mbit/s downlink)

• ERC-32 based DHS• S-band small ground station

(2,4 m dish)

• 3-axis stabilised ACNS – 4 reaction wheels– 4 magnetotorquers– 2 three-axis

magnetometers– 1 Star Tracker with 2

optical heads– 1 Star Tracker as part of

CHRIS– 1 GPS with 4 antennas

October 2000 Slide 8

PROBA Accommodation

October 2000 Slide 9

PROBA flight structure

October 2000 Slide 10

Proba launch / orbit

• Low Earth Orbit (LEO) 560x720 km• Near polar with an inclination of 97.7 °• Polar Satellite Launch Vehicle (PSLV)• Launch by Antrix/ISRO, India• Launch site : Shriharikota• Scheduled launch 2001

October 2000 Slide 11

PROBA Avionics

• Dual ERC 32 based avionics for ACNS and DHS/TT&C

• Payload Computer– DSP (21020) for image processing/compression– Integrated mass memories (for HK and Science data)– Smart Instrumentation points and house keeping bus experiment

• TT&C in S-band CCSDS

October 2000 Slide 12

PROBA Power

• Ga As Solar Arrays (90W peak power)• 36 Li-ion cells, 9Ah, 25V • Central protected power

distribution with regulated

bus.

October 2000 Slide 13

PROBA ACNS

ACNS Software - Navigation - Guidance - Control

Reaction Wheels (4)

Magnetometers (2)

Magneto-torquers (4)

GPS Receiver

Star Tracker (2)

Head

Head

Star Tracker(payload)

Resonating gyroscope

• ACNS– 3-axis control: high accuracy pointing and manoeuvring

• (absolute pointing accuracy better than 360 arcsec)

– Gyro-less attitude control– Navigation function (autonomous orbit estimation)– Guidance function (f.e. Fly By predictions)– ACNS automated software generation

• ACNS Technology demonstrations:

• Star Tracker• Resonating Gyroscope• GPS Attitude Determination

October 2000 Slide 14

PROBA ACNS

• ACNS Block Diagram

October 2000 Slide 15

ACNS Components

• GPS receiver– Position and velocity determination, Time synchronization with UTC,

attitude determination experiment (SSTL)

• Redundant star tracker with dual head– High Accuracy (arcsec range), autonomous attitude determination from

“Lost in Space” situation, compatible with tumbling rates of up to 1.2°/sec

• 4 Miniature Reaction Wheels– Storage capacity 0.04 Nms, – Momentum 5 mNm

• 2 Magnetometers• 4 Magnetotorquers

October 2000 Slide 16

PROBA Payloads

• Compact High Resolution Imaging Spectrometer– 25 m resolution– 19 spectral bands (415 - 1050 nm) – Bi-directional Reflectance Distribution Function measurements

October 2000 Slide 17

PROBA Payloads

Imaging with CHRIS (BRDF measurements)

19 km

Beginimaging

Endimaging

Line of sightof imager

Image 2Image 4Image 5 Image 1Image 3

1

23

45678

9

10

October 2000 Slide 18

PROBA Payloads

Imaging with CHRIS (BRDF measurements)

October 2000 Slide 19

PROBA Imagers

• High Resolution Camera• Panchromatic • 10 m ground resolution• 3D Packaging Technology CCD

•Wide Angle Camera• Miniaturised (7x7x6 cm) • CMOS Active Pixel Sensor

October 2000 Slide 20

PROBA Earth Environment Instruments

SREM• Standard Radiation Environment Monitor• Objectives:

– Earth radiations environment– Space weather

DEBIE• Debris In-orbit Evaluator

• Objectives:– Sub-millimeter debris population– Knowledge and models

SREM

DEBIE

October 2000 Slide 21

PROBA Payloads

• Earth Environment Instruments

SREM

DEBIE

October 2000 Slide 22

PROBA Ground Station

S/C

PGS AGS

End User

WWWServer

MCS

Mission

INTERNET

TM/TCTM

ACS

ArchivesArchives

UserRequests

Repor tsNoti¼cations

End User

• S-Band• 2.4 m Transportable Antenna (Redu, BE)• ESOC network compatible: packet TC/TM, SCOS Spacecraft control• Data Distribution via network/web• “Light-out” ground station

October 2000 Slide 23

PROBA Development

• STM – Table model Avionics – PFM

• Integrated SVF/SCOS based development (SW, EGSE, spacecraft simulator, operations)

• Automated SW generation for ACNS

October 2000 Slide 24

PROBA Status