Solar Orbiter was launched in February 2020 and is on its way to perform close-up studies of our Sun. The spacecraft will brave the fierce heat and carry its scientific instruments to just one-quarter of Earth's distance from our star. There, it will help us better understand and predict the Sun’s behaviour, on which life on Earth depends.
The spacecraft will be used to examine how the Sun creates and controls the heliosphere, the vast bubble of charged particles blown by the solar wind into the interstellar medium. The spacecraft will also be the first satellite to provide close-up views of the Sun's polar regions, which are very difficult to see from Earth. By tracking the same region of the solar atmosphere for much longer than is possible from Earth, Solar Orbiter will allow researchers to watch storms building up and developing in the atmosphere over several days.
Solar Orbiter launched from Cape Canaveral, Florida, on an Atlas V 411 rocket supplied by NASA in February 2020. Soon after lift-off and separation from the rocket, flight control teams at ESOC in Darmstadt, Germany, took over, working round the clock to navigate the spacecraft 42 million km towards the Sun. Along with flight dynamics experts, software specialists and others, the control team will get Solar Orbiter closer to the Sun than any European spacecraft in history, and into a high inclination orbit that will allow it to take the first direct images of its polar regions.
To alter its trajectory and guide it towards the innermost regions of the Solar System, Solar Orbiter will perform five gravity-assist manoeuvres around Venus and two around Earth. During these manoeuvres, it acquires in situ data and characterises and calibrates its remote-sensing instruments. The first close solar pass will take place at the end of March 2022 at around a third of Earth’s distance from the Sun.
Upon arriving in the near-vicinity of the Sun, the spacecraft will initially be in an elliptical orbit with a period of 180 days. Solar Orbiter will eventually pass as close as 42 million km of the Sun’s surface - approximately 60 solar radii - during perihelion.
Solar Orbiter communicates with Earth via ESA’s Estrack deep-space ground stations. Science data are collected and stored on the spacecraft, and then downlinked during designated eight-hour communications windows with ESA’s 35-m Malargüe ground station in Argentina. Other Estrack stations such as the 35-m antennas in New Norcia, Australia, and Cebreros, Spain, act as backups.