ESA’s first small satellite PROBA for in-orbit technology
demonstration is now well under way and turning out great pictures
of the Earth.

"We are very happy with PROBA and the results from this small
satellite. It has now been in orbit for eight months and platform,
instruments and ground segment are performing well," says Frederic
Teston, PROBA Project Manager at ESA. "We have now decided to make
available on the Internet some of the pictures taken by PROBA
during spacecraft commissioning."

PROBA (Project for On Board Autonomy) was launched on 22 October
last year and is ESA’s first small autonomous spacecraft. It
operates with limited intervention from the ground, autonomously
performing on board everyday tasks as guidance, navigation,
control, onboard scheduling and payload resource management.

PROBA is part of the Agency’s in-orbit Technology Demonstration
Programme’s overall effort to promote technological missions using
small spacecraft. It was built by a consortium of small companies
and institutes from seven European countries and Canada, led by
the Belgian prime contractor Verhaert.

Strong processing for autonomy

PROBA, although tiny — a 97 kg cube of only 60x60x80 cm, includes
some of the most advanced on-board processing technology ever used
on satellites to provide full autonomous operation.

It carries the highest-performance computer system flown by ESA so
far. This is a space version of a standard commercial processor
intended to validate a possible computing core for future
spacecraft. One Gigabit on-board memory is used for autonomous
on-board data storage, until they are downloaded on a high-speed
one-Megabit per second link to the ground station in Redu, Belgium.

Loaded with high-tech

PROBA demonstrates technology miniaturisation and the potential of
small satellites. With only 25 kg available for payload, stringent
requirements were imposed, but this did not limit the capabilities
of the six payloads, all dedicated to research.

"Small satellites such as PROBA offer the opportunity for rapid
flight-testing of technologies such as miniature digital cameras
and distributed sensing devices, all of which are important for
future ESA missions and European industrial competitiveness,"
says Frederic Teston.

PROBA images on line

ESA is now making available on the Internet images from the Compact
High Resolution Imaging Spectrometer (CHRIS). This instrument,
produced by Sira Electro-Optics (UK), is with its 14 kg the
largest instrument onboard.

"With the onboard GPS system and the autonomous star sensor
technology, PROBA is one of the best-performing small satellites
in production," continues Teston. "Combining this with its
advanced manoeuvring capability, will provide particularly
interesting recording features of vegetation and aerosol. 40
Principal Investigators, are preparing to analyse these data,
which should make it possible to distinguish between variations
in leaf biochemistry and leaf/canopy structure."

A first set of images can be viewed and downloaded from the new
ESA PROBA web site at
The site also provides more detailed information on this small but
very advanced ESA satellite.

More information

* PROBA web site
* Wanted: instruments for testing on next Proba mission

Related articles

* First PROBA pictures promise wealth of environmental data
* Indian launch success for European micro-satellite

* Micro-satellite will hook into Internet

Related links


* PROBA mission [PDF file, 282KB]

* Verhaert PROBA-I website website_files/frame.htm


[Image 1:]
The Mauna Kea volcano, Hawaii, seen by PROBA-1’s CHRIS instrument.
Date of acquisition: 18 April 2002 Credits: ESA

[Image 2:]
Konakri, Guinea, seen from PROBA-1’s CHRIS instrument.
Date of acquisition: 05 March 2002 Credits: ESA

[Image 3:]
A consortium of European companies from seven countries, including
many Small and Medium Size Enterprises (SMEs) developed PROBA 1,
seen here during environmental testing at Intespace.

The participating companies include:


* Verhaert: Prime Contractor

* Spacebel: On-board Software

* Space Application Services: Ground Segment

* OIP: High Resolution Camera (HRC), Wide Angle Camera (WAC)


* SSF: Software Validation

* Finnavitac: Debris In-Orbit Evaluator (DEBIE)


* Sherbrooke University/NGC Aerospace: Attitude Control and
Navigation System Software


* Technical University of Denmark: Startracker


* SIRA Electro-Optics: Compact High Resolution Imaging Spectrometer

* SSTL: GPS Receiver

* Astrium Ltd: Payload Processor Unit

* AEA Technology: Batteries


* Contraves: Space Radiation Environment Monitor (SREM)


* Galileo Avionica: Solar Panels


* Teldix: Reaction Wheels

The Netherlands:

* Dutch Space: Magneto-torquers

* Xensys: Miniaturised Radiation Monitor (MRM)

* Xensor: Smart Instrumentation Point (SIPS)

Credits: Verhaert

[Image 4:]
The Compact High Resolution Imaging Spectrometer (CHRIS) from Sira
Electro-Optics (UK) is PROBA’s largest instrument. The scientific
objective is to provide multi-spectral data on Earth surface
reflectance in the visible and near-infrared spectral band. The
spectral bands are fully programmable within the range 415-1050 nm
and up to 19 frequency bands can be acquired simultaneously at full
resolution. This capability will provide particularly interesting
recording features for lad areas of vegetation and aerosol.

[Image 5:]
Rupel and Schelde rivers, Belgium, seen from PROBA-1’s CHRIS
Date of acquisition: 11 March 2002 Credits: ESA

[Image 6:]
San Francisco seen from PROBA-1’s CHRIS instrument.
Date of acquisition: 17 June 2002 Credits: ESA