Solar Orbiter is the first mission in ESA’s Cosmic Vision programme to start its implementation phase and is scheduled for launch in 2017. The mission lifetime will be seven years.
ESA awarded Astrium the contract to build Solar Orbiter in April 2012.
Solar Orbiter builds on hugely successful missions such as SoHO and Ulysses. Like those missions, it is a collaboration between ESA and NASA, including major scientific payloads from the United States, and the provision of a launch by NASA.
Solar Orbiter will study the role of the engine at the very centre of the solar system – the sun. It will explore the origins of the solar wind, how acceleration of particles takes place, and how turbulence develops. It will trace the evolution of transient phenomena such as coronal mass ejections. Solar Orbiter will study the lifecycles of energetic particles – their sources, acceleration processes and distributions in space and time. It will increase knowledge of the solar dynamo that drives the connection between the sun and heliosphere, especially at high solar latitudes.
It is not possible to do these things from close to the Earth, where scattering and mixing have changed the properties of the solar wind and magnetic field. Solar Orbiter will circle nearer to the sun than any space probe to date, to perform a close-up study of the uncharted innermost regions of the solar system, at locations where it can view the sun’s high latitudes, and observe the links between the sun’s surface, its corona and heliosphere over dynamically important timescales.
Solar Orbiter will carry a suite of complementary instruments that will measure the particles, fields and waves of the plasma through which it travels, simultaneously making multi-wavelength remote-sensing observations of the sun’s photosphere, corona and heliosphere.
- In-situ observations will target the ions and electrons of the solar wind, and populations of shock-accelerated particles. The magnetic field will be measured, together with the properties of waves in the solar wind plasma.
- Remote sensing will map at high resolution the magnetic field distribution on the sun’s photosphere and its line-of-sight motions, coronal structures in visible, UV and EUV wavelengths and coronal UV spectra. Flares will be studied by imaging X-ray spectroscopy, while wide-field contextual imagery will trace heliospheric features out to 40°.
In this way, Solar Orbiter will measure phenomena of generation and acceleration from the photosphere out into the solar wind in which the spacecraft is embedded.