Proba-3 Platforms
Both the larger Coronagraph and the smaller Occulter satellites are derived from ESA’s standard Proba platform.
The 340 kg Coronagraph satellite has a volume of 1100 x 1800 x 1700 mm3. It hosts the coronagraph instrument which will point directly toward the Sun . The power is provided from a deployable solar array.
Its guidance, navigation and control (GNC) system consists of four reaction wheels, 2x3-axis gyroscopes, one three-headed star tracker, six Sun sensors and two GPS receivers. The Coronagraph spacecraft is also equipped with mono-propellant thrusters, to be able to perform large manoeuvres, such as formation acquisition at entry to the apogee arc, and formation break at the end.
The 200 kg Occulter satellite has a volume of 900 x 1400 x 900 mm3. Its main task is simply to block the Sun for the coronagraph instrument, with a 1400-mm diameter occulting disk on its face pointing away from the Sun.
The opposite side accommodates the satellite’s solar array. Its GNC system consists of four reaction wheels, three three-axis gyroscopes, one triple-headed star tracker, six Sun sensors and two GPS receivers. The satellite also hosts the optical metrology sensors.
