Preliminary design for the larger of the two Proba-3 spacecraft

Proba-3 is the third in ESA’s series of missions for validating developments in space systems while carrying an ‘added value’ user payload which can directly benefit from the innovations under test.

Formation flying technologies will make new types of missions possible and provide a leap in the performance of future science, Earth observation and application missions.

Mastering formation flying missions requires the development of specific technologies well beyond the present state-of-the-art in fields such as metrology and spacecraft guidance, navigation, and control.

Proba-3, has completed the preparatory phase and will comprise two independent, three-axis stabilised spacecraft flying close to one another with the ability to accurately control the attitude and separation of the two craft.

Utilising either cold-gas or electrical thrusters for agile manoeuvring, and both radio-frequency and optical (laser-based) metrology techniques for accurate position measurement and control, the combined system is expected to achieve sub-millimetre relative positioning accuracy over a separation range of 25 to 250 metres.