Facts and figures

Proba liftoff
Proba liftoff onboard PSLV

Mission  
Launch date 22 October 2001
Launch site Sriharikota, India
Launcher Antrix/ISRO PSLV-C3
Orbit LEO Sun-synchronous
Orbital parameters 681x561 km
Orbital plane inclination 97.9 degrees
Orbital period 96.97 minutes
Mission duration One year (planned)
Number of instruments Eight
Number of technological payloads Six
Mission operations and ground station ESA/REDU dedicated 2.4 m dish, average of 4 contacts of 10 m/day, automated evening & weekend passes
Proba during vibration tests
Proba PFM during vibration tests

Spacecraft  
Spacecraft mass 94 kg
Instrument mass 25 kg
Technological payload mass 30 kg
Shape 60x60x80 cm box shaped aluminium honeycomb structure

Proba-1 platform features

  • Computing system (highest performance computing system yet flown on an ESA spacecraft)
  • ERC-32 (SPARC V7) processor, >80 krad, 10 MIPS, 2 MFLOPS
  • TCS 21 020 digital signal processor, >100 krad, 15 MIPS, 45 MFLOPS
  • 12 other processors in subsystems/payload
  • off-the-shelf operating system (Vx Works)
  • full automatic code generation of all attitude control and navigation software (~50 000 lines of code)
  • 3-axis stabilisation (Earth pointing or inertial) by four miniaturised reaction wheels
  • absolute pointing accuracy: 150 arcsec
  • relative pointing stability: 10 arcsec over 10 s
  • 2-headed star tracker providing arcsec level pointing knowledge
Sriharikota, India 8 February 2002
Sriharikota, India - CHRIS image - 8 February 2002
  • GPS sensor providing 20 m position and fly-by knowledge

  • Spacecraft agility (along- and across-track), enabling multiple payload imaging (typically 5) of the same target in the same pass
  • Slew rate: up to 1 deg/s
  • Autonomous navigation via GPS and orbit propagation (no propulsion)

  • GaAs solar cells on five structure faces
  • 120 W peak
  • 17 W in safe mode
  • 28 Vdc regulated power bus
The Mauna Kea volcano, Hawaii 15 April 2002
Mauna Kea volcano, Hawaii - CHRIS image - 15 April 2002
  • 9 Ah Li-Ion battery

  • Passive thermal-control system

  • 1 Mbit/s S-band downlink

  • 4 kbit/s uplink

  • 1.2 Gbit data storage

Last update: 27 May 2009

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