The PROBA Platform and its Orbital Characteristics

The Project for On-Board Autonomy (PROBA) satellite mission to be carried as a second passenger on an Indian Launcher in 2000 is a technology experiment to demonstrate the on-board autonomy of a generic platform suitable for small scientific or application missions. The main structure, orbit and attitude control systems, on board computers and telemetry is an ESA development and is funded by them. Figure 7 shows an exploded view of the inside of PROBA that is shown as a computer generated image in Figure 8.

A number of different Earth observation instruments have been included in the payload to test the platform pointing and data management capabilities. The payloads, including CHRIS are not funded by ESA but ESA is offering them a free ride on board the platform. The instrument payload includes:

CHRIS
a radiation measurement sensor called SREM
a debris measurement sensor called DEBIE
a wide angle Earth pointing camera
>a star tracker and gyroscopes

PROBA is 3 axis stabilized which provides nadir, off-nadir or inertial pointing. It includes:

 An autonomous (lost in space) double head star tracker
Navigation and attitude with GPS sensor
Momentum wheels
>Magneto-meters and magneto-torquers
No active propulsion
High performance RISC computer
A Solid state mass memory of 1.2 Gbits which can be downloaded every 12 hours given ground station visibility and data down-link capacity.
High performance digital signal processor

Each CHRIS image represents about 131 Mbits of data so that the 1 Gbit of mass memory that is assigned to CHRIS can store several images taken at different view angles.

Key PROBA Characteristics:
 
 

PROBA Orbital Characteristics

PROBA  Attitude Orbital Control System (AOCS) manoeuvring requirements

Some Two Line Elements for PROBA



Page last modified 9 March 2002