Solar Orbiter, launched on 10 February, completed its commissioning phase in mid-June and performed its first close approach to the Sun. Shortly thereafter, the European and US science teams behind the mission’s 10 instruments were able to test the entire instrument suite in concert for the first time.
Better than expected
Despite the setbacks the teams faced while commissioning the spacecraft and its instruments amid the COVID-19 pandemic, the first imaging campaign has been a great success.
“The first images are exceeding our expectations,” says Daniel Müller, Solar Orbiter Project Scientist at ESA. “We can already see hints of very interesting phenomena that we have not been able to observe in detail before. The 10 instruments on board Solar Orbiter work beautifully, and together provide a holistic view of the Sun and the solar wind. This makes us confident that Solar Orbiter will help us answer profound open questions about the Sun.”
We have never been closer with a camera
No other images of the Sun have been taken from such a close distance. During its first perihelion, the point in the spacecraft’s elliptical orbit closest to the Sun, Solar Orbiter got as close as 77 million kilometres from the star’s surface, about half the distance between the Sun and Earth. The spacecraft will eventually make much closer approaches to the Sun. The spacecraft is now in its cruise phase, gradually adjusting its orbit around the Sun. Once in its science phase, which will commence in late 2021, the spacecraft will get as close as 42 million kilometres from the Sun’s surface, closer than the planet Mercury. The spacecraft’s operators will gradually tilt Solar Orbiter’s orbit to enable the probe to get the first proper view of the Sun’s poles.
An international mission
Solar Orbiter is a space mission of international collaboration between ESA and NASA. Twelve ESA Member States (Austria, Belgium, the Czech Republic, France, Germany, Italy, Norway, Poland, Spain, Sweden, Switzerland, and the United Kingdom) as well as NASA contributed to the science payload. Denmark, Finland, Ireland, Luxembourg, the Netherlands and Portugal contributed to building the spacecraft but not to the science payload.
The UK played a key role in development of the Solar Orbiter mission. The spacecraft was built by Airbus Defence and Space in Stevenage. British scientists are involved in four out of the ten instruments aboard the spacecraft. Researchers from Imperial College London and the UCL Mullard Space Science Laboratory (UCL MSSL) lead the teams behind Solar Orbiter’s Magnetometer (MAG) and Solar Wind Analyser (SWA) respectively. UCL also has a key role in the Extreme Ultraviolet Imager (EUI), which will enable the scientists to study processes on the Sun in greater detail than ever before. STFC RAL Space led the consortium that developed and built the extreme ultraviolet imaging spectrometer SPICE