Orbit: Solar Orbiter will be placed into an elliptical orbit around the sun coming as close to 26 million miles away from the star every five months -- even closer than Mercury. It will take three years to reach this orbit. When travelling at its fastest, Solar Orbiter will remain positioned over approximately the same region of the solar atmosphere as the sun rotates on its axis, allowing unprecedented observations. The inclined orbit will allow Solar Orbiter to better image the regions around the sun’s poles than ever before.
Solar Orbiter is a joint ESA/NASA collaboration that will address a central question of heliophysics: How does the sun create and control the giant bubble of magnetic fields around it, the heliosphere? To answer this question, Solar Orbiter will make in-situ measurements of the solar wind plasma, fields, waves, and energetic particles by traveling closer to the sun than the previous record-holders, Helios 1 and 2 – traveling nearly three-quarters of the way to the sun, a journey of approximately 67 million miles. At that distance, Solar Orbiter will be able to observe solar processes that are still relatively pristine and have not had their properties modified by subsequent transport and propagation processes.