The Project for On-Board Autonomy (Proba) was originally a technology demonstration mission of the European Space Agency, started in mid-1998 and funded within the frame of ESA's General Support Technology Programme.

Intended as a one-year mission, Proba has provided data successfully ever since its launch on 22nd Oct 2001. Hosting two Earth Observation instruments CHRIS and HRC, Proba is since 2004 managed by ESA's Ground Segment Department within the Directorate of Earth Observation at ESA/ESRIN.  ESA's Project for On-Board Autonomy (Proba) spacecraft is one of the most advanced small satellites ever flown in space. Launched in 2001, as a technology demonstration mission it is now operating as an Earth Observation Third Party Mission.

Proba performs autonomous guidance, navigation, control, onboard scheduling and payload resources management. Its payload includes a compact multi-spectral imager and high-resolution camera.

Just 60x60x80 cm and weighing only 94 kg, Proba aims to use and demonstrate automatic functions, both onboard and in the mission ground segment.

Proba's main payload is a hyperspectral instrument weighing just 14 kg called CHRIS – standing for Compact High Resolution Imaging Spectrometer. Despite this small size and a power requirement of just nine watts CHRIS can image an 18.6 square km area at multiple angles, achieving a resolution of 17 m in up to 19 programmable spectral bands. Furthermore its agile platform can be tilted during acquisition to provide images of the same site taken at different angles.

That means CHRIS returns a wealth of biophysical and biochemical data as well as visual information about a given target, and can be used for activities including environmental monitoring, crop forecasting, forest cataloguing and marine science.

Also aboard is the compact High-Resolution Camera (HRC), which acquires black and white 16-km square images to a resolution of five metres.