The Mission

The Solar Orbiter Mission is a collaboration between ESA and NASA. The mission aims to understand how the Sun creates and controls the heliosphere. Scheduled for launch in February 2020, the mission will provide close-up, high-latitude observations of the Sun, aproaching the sun at 0.28 au at perihelion and reaching ~33º heliospheric latitudes at the latest stages of the mission. Solar Orbiter will reach its nominal orbit two years after launch. The nominal phase will cover 7 years of observations (13 years including a extension phase). SolO will serve of several gravity assist manoeuvres (GAMs) at Earth and Venus to increase the orbit inclination to provide unparalell observations of the solar poles.

The Science

The mission aims to understand how the Sun creates and controls the heliosphere. In order to achieve this goal, Solar Orbiter has been specifically designed to identify the origins and causes of the solar wind, the heliospheric magnetic field, solar energetic particles, transient interplanetary disturbances, and the Sun's magnetic field. Understanding the interplay between the complex physical processes at work in this system is the central goal of heliophysics. Since the Sun and presumably the heliosphere are typical of many small stars and their stellar spheres, these studies are not only relevant to astrophysics, but are unique since the Sun alone is close enough for detailed study.
Addressing these topics entails answering the following specific questions:

• What drives the solar wind and where does the coronal magnetic field originate from?
• How do solar transients drive heliospheric variability?
• How do solar eruptions produce energetic particle radiation that fills the heliosphere?
• How does the solar dynamo work and drive connections between the Sun and the heliosphere?

A detailed compilation of the different scienctific topics Solar Orbiter will address can be found in the Science Activity Plan (SAP)

The Payload

The scienctific payload of Solar Orbiter comprises both remote-sensing and in-situ instruments. The in-situ instruments will operate continuously while remote-sensing observations will be carried out every orbit around closest approaches and at the minimum and maximum heliographic latitudes. Given the broad scientific instrumentation aboard and the peculiarities of every orbit, specific observational campaigns will be devoted to particular scientific objectives in the course of the mission. The instrumentation aboard includes:

In-situ instrumentation:

• EPD: Energetic Particle Detector
• MAG: Magnetometer
• RPW: Radio and Plasma Waves
• SWA: Solar Wind Plasma Analyser

Remote-sensing instrumentation:

• EUI: Extreme Ultraviolet Imager
• METIS: Coronagraph
• PHI: Polarimetric and Helioseismic Imager
• SOLOHI: Heliospheric Imager
• SPICE: Spectral Imaging of the Coronal Environment
• STIX: X-ray Spectrometer/Telescope