The Project for On-Board Autonomy-1 (PROBA-1) 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, this small satellites - less than 1 cubic metre in size - has provided data since its launch on 22 October 2001 and is still operational today.
|Orbital parameters||681x561 km|
|Orbital plane inclination||97.9 degrees|
|Orbital period||96.97 minutes|
|Repeat cycle||Approx. 7 days|
PROBA-1 rolls in its orbit to take images: the satellite’s platform and payload work as one: spinning reaction wheels guided by a star tracker roll it up to 25º side to side and ±55º/±36º along its path. This helps PROBA-1 to compensate for its 7.5 km/s speed, like a photographer panning to snap a moving target. So each target can be seen on up to 5 different angles (-55º, -36º, nadir view, +36º and +55º).