18 October 2019
The UK-built Solar Orbiter spacecraft, which will investigate the workings of our Sun, is preparing to leave the test facility in Germany to head for its launch site in the USA.
Due to launch in February 2020, Solar Orbiter will perform unprecedented close-up observations of the Sun. It will allow scientists to study the Sun in much more detail than previously possible and to observe specific features for longer periods than can be reached by any spacecraft circling the Earth. In addition, Solar Orbiter will measure the solar wind close to the Sun and provide high-resolution images of the uncharted polar regions of the Sun.
The UK has played a vital role in the conception and creation of this satellite, with STFC’s RAL Space, University College London and Imperial College London leading international teams to design and build three instruments. UK scientists, including those from RAL Space, were instrumental in proposing the Solar Orbiter mission to ESA. The UK Space Agency funded the development of two out of the 10 scientific instruments on board the spacecraft, and contributed to a further two.
Science Minister Chris Skidmore said: “I am delighted that the UK has played such a leading role in this mission to observe uncharted regions of the Sun. From mobile phones to electricity networks, our scientists will make new discoveries about the impacts of space weather on our daily lives.
“Our commitment to the European Space Agency means UK research and engineering teams will continue to be at the heart of the new space age after we’ve left the EU, creating highly-skilled jobs and supporting our economy.”
Solar Orbiter will carry 10 state-of-the-art instruments. Remote sensing payloads will perform high-resolution imaging of the Sun's atmosphere – the corona – as well as the solar disk. Other instruments will measure the solar wind and the solar magnetic fields in the vicinity of the orbiter. This will give us unprecedented insight into how the Sun works, and how we can better predict periods of stormy space weather, which are related to coronal mass ejections (CMEs) that the Sun throws towards Earth from time to time.
The Spectral Investigation of the Coronal Environment (SPICE) instrument, which was built by RAL Space, is a high resolution imaging spectrometer observing at extreme ultraviolet wavelengths. It will help solve one of the secrets of the Sun - where exactly does the solar wind come from and how does it speed up and escape from the Sun. RAL Space led the international consortium, under contract to ESA and with contributions from the UK Space Agency and other European countries.
RAL Space’s Dr Andrzej Fludra, lead on the SPICE instrument consortium, said: “Building SPICE has been a great achievement for our international team, led by RAL Space. For several years, engineers and scientists from the UK, France, Germany, Norway, Switzerland, the US and ESA worked closely together on specifying the science requirements, designing, building and testing the instrument.
“We are now getting ready to make observations of the Sun, preparing software and on-board procedures that will control the instrument. I have great hopes and expectations that we will be able to solve the remaining mysteries about the solar activity and how it affects the heliosphere.”
From the spacecraft’s unique vantage point, SPICE will carry out the first-ever spectral observations of the solar polar regions. SPICE will help trace solar wind structures measured at the spacecraft to their sources at the poles inside dark, slightly cooler areas of the Sun known as coronal holes.
By recording the ‘fingerprint’ at extreme ultraviolet wavelengths from a wide range of ionized atoms including carbon, neon, oxygen and iron, SPICE will measure the composition and speed of plasma flowing out from the Sun and help us find where it comes from. These ions are formed at temperatures from 10,000 to 10 million Kelvin, covering different layers of the solar atmosphere, from the chromosphere up to the corona.
Chris Lee, Chief Scientist at the UK Space Agency, said: “Solar Orbiter is the most important UK space science mission for a generation, both because of its leading roles for UK science and industry but also because of the crucial information it will give us about living near a star like the Sun. It has never been more important to understand this interaction because of the impact space weather can have on our satellite enabled economy.”
Solar Orbiter, which will take just under two years to reach its initial operational orbit, will follow in the footsteps of NASA’s Solar Parker Probe, which launched in 2018. The two missions will offer complementary perspectives of the Sun – Parker Solar Probe will travel through the Sun’s atmosphere, while Solar Orbiter will observe the surface.
The UK is a global leader in solar science with organisations like RAL Space working at the forefront of efforts to understand our nearest star and assess and mitigate the impact of space weather on Earth.
As well as leading instrumentation for science missions like ESA’s Solar Orbiter and NASA’s STEREO mission, RAL Space is leading an international team developing instruments for ESA’s Lagrange mission which will be part of an early warning system for severe space weather and working with the Natural Environment Research Council on a new £20 million fund to connect the space weather research community with the Met Office Space Weather Operations Centre.
UK teams from University College London, Imperial College London and the Science and Technology Facilities Council’s RAL Space are involved in 4 out of the 10 instruments. The UK Space Agency is funding the UK involvement.
The mission orbit is designed to be synchronous with the Sun’s rotation, providing long duration observations for the first time. This will enable the mission to observe the build-up of events such as solar storms.
The instruments on board will undertake remote sensing observations of solar features and in situ measurements of the solar wind bombarding the spacecraft. This combination of remote and in situ instruments will enable in-depth studies of the close link between the origin of solar features such as solar eruptions and their emergence into space. This unique mission could provide major breakthroughs in our understanding of how the inner solar system works and is driven by the solar activity.
The three-axis stabilised design of the spacecraft is being developed to withstand the scorching heat from the Sun that will hit one side and the cold of space on the opposite side which will usually be in shadow.
Solar Orbiter is managed and financed mainly by ESA with strong international collaboration with NASA as part of the International Living with a Star initiative.
Last updated: 24 October 2019