The Solar Orbiter Mission

Solar Orbiter is a mission dedicated to solar and heliospheric physics. It was selected as the first medium-class mission of ESA's Cosmic Vision 2015-2025 Programme. The programme outlines key scientific questions which need to be answered about the development of planets and the emergence of life, how the Solar System works, the origins of the Universe, and the fundamental physics at work in the Universe. 


Solar Orbiter is the most complex scientific laboratory ever to have been sent to the Sun. Although our life-giving star has been an object of scientific interest for centuries, its behaviour still presents a puzzle for scientists. Solar Orbiter will take images of the Sun from closer than any spacecraft before and for the first time look at its uncharted polar regions. By combining observations from Solar Orbiter’s six remote-sensing instruments and four sets of in situ instruments, scientists hope to find answers to some profound questions: What drives the Sun’s 11-year cycle of rising and subsiding magnetic activity? What heats up the upper layer of its atmosphere, the corona, to millions of degrees Celsius? What drives the generation of the solar wind? What accelerates the solar wind to speeds of hundreds of kilometres per second? And how does it all affect our planet?

Launch date: February 2020

Completed milestones: First images released in July 2020

Beginning of routine science operations: November 2021

Mission highlights: The closest ever images of the Sun, the first ever close-up images of the Sun’s polar regions, measuring the composition of the solar wind and linking it to its area of origin on the Sun’s surface.

The closest distance to the Sun: 42 million kilometres.


Solar Orbiter Overview

Solar Orbiter is an international cooperative mission between ESA (the European Space Agency) and NASA that addresses a central question of heliophysics: How does the Sun create and control the constantly changing space environment throughout the solar system? The Sun creates what’s known as the heliosphere — a giant bubble of charged particles and magnetic fields blown outward by the Sun that stretches more than twice the distance to Pluto at its nearest edge, enveloping every planet in our solar system and shaping the space around us. To understand it, Solar Orbiter is traveling as close as 26 million miles from the Sun, inside the orbit of Mercury to measure the magnetic fields, waves, energetic particles and plasma escaping the Sun while they are still in their pristine state, before being modified and mixed in their long journey from the Sun. 



With a scientific payload of 10 different instruments — each complementing and supporting the others — Solar Orbiter combines high-resolution telescopes with measurements from the environment directly surrounding the spacecraft. Together the observations create a one-of-a-kind, comprehensive picture of the Sun's inner workings and how they can affect the space environment further out in the solar system. 



Solar Orbiter launched from Cape Canaveral on a United Launch Alliance Atlas V 411 rocket on Feb. 9, 2020 at 11:03 p.m. EST. It now follows an elliptical orbit around the Sun, completing one revolution every 168 days. Using gravity assists from Venus and Earth, Solar Orbiter is gradually lifting itself out of the ecliptic plane, ultimately reaching an angle of 24 degrees above the Sun’s equator (33 degrees for the extended mission). From this vantage point Solar Orbiter is capturing the first ever images of the Sun’s north and south poles from high latitudes. At its fastest, Solar Orbiter can almost catch up to the Sun’s rate of rotation, allowing the spacecraft to hover over specific spots on the Sun as it turns and study how a single solar feature evolves over time.



Solar Orbiter joins NASA’s Parker Solar Probe in studying our star from closer than any spacecraft before them. Working together, Solar Orbiter's comprehensive suite of instruments and NASA’s Parker Solar Probe's up-close view of the Sun provide a never-before-seen global view of our star.  Various conjunctions of the two missions over their life spans allow observations along different points of the same magnetic field lines and outflow of material, or allow one mission to provide a larger context view of the space the other one is traveling through. 


By approaching as close as 0.28 AU, Solar Orbiter will view the Sun with high spatial resolution and combine this with in-situ measurements of the surrounding heliosphere. Thanks to its unique orbit, Solar Orbiter will deliver images and data of the unexplored Sun's polar regions and the side of the Sun not visible from Earth.