SOLar Orbiter mission (SOLO)

The goal of the Solar Orbiter mission, developed jointly by the ESA and NASA, is to study the sun and magnetic activity in the heliosphere; it will able to obtain unique information which will help to understand how this star functions and even to predict its behaviour.

Its objectives are to determine the properties, dynamics and interactions between the solar plasma, the magnetic fields and the particles in the heliosphere around the sun; to investigate the relationship between the sun’s surface, corona and inner heliosphere; to explore the energetic particles, dynamics and fine-scale structure of the sun’s magnetised atmosphere at all altitudes; and to probe the solar dynamo by observing the star’s higher latitudes and the movements of its seismic waves.

Solar Orbiter has been designed to carry a large payload of scientific instruments to the region close to the sun. In fact, it will be the first satellite to provide close-up views of the sun’s polar regions, which are difficult to see from the Earth, providing images from latitudes greater than 25 degrees. For a few days, it will fall in with the sun’s rotation around its axis, allowing the development of a solar storm to be observed for a prolonged period from the same perspective. It will also provide data from the side of the sun not visible from the Earth.

The intense radiation and high temperatures to which the equipment will be exposed has posed a number of technical and technological challenges in the satellite’s development. The equipment positioned on the probe’s exterior: when the satellite reaches its orbit’s closest point to the sun, it will need to withstand solar radiation of 17,000 Watts per square meter, and the external equipment will reach operating temperatures in the 400°C range. At the orbit’s farthest point from the sun, the satellite will experience temperatures under –100°C. This is true for the communication antenna, whose subsystem will be provided by Sener. This subsystem includes a high-gain swivelling reflector, the orbiter’s mid-gain swivelling antenna and its two low-gain antennas. For the high- and mid-gain antennas, Sener is also responsible for the separation booms, the deployment and pointing mechanisms, the thermal hardware and the control electronics.