The Solar Orbiter mission

Abstract

Aims. Solar Orbiter, the first mission of ESA’s Cosmic Vision 2015–2025 programme and a mission of international collaboration between ESA and NASA, will explore the Sun and heliosphere from close up and out of the ecliptic plane. It was launched on 10 February 2020 04:03 UTC from Cape Canaveral and aims to address key questions of solar and heliospheric physics pertaining to how the Sun creates and controls the Heliosphere, and why solar activity changes with time. To answer these, the mission carries six remote-sensing instruments to observe the Sun and the solar corona, and four in-situ instruments to measure the solar wind, energetic particles, and electromagnetic fields. In this paper, we describe the science objectives of the mission, and how these will be addressed by the joint observations of the instruments onboard. Methods. The paper first summarises the mission-level science objectives, followed by an overview of the spacecraft and payload. We report the observables and performance figures of each instrument, as well as the trajectory design. This is followed by a summary of the science operations concept. The paper concludes with a more detailed description of the science objectives. Results. Solar Orbiter will combine in-situ measurements in the heliosphere with high-resolution remote-sensing observations of the Sun to address fundamental questions of solar and heliospheric physics. The performance of the Solar Orbiter payload meets the requirements derived from the mission’s science objectives. Its science return will be augmented further by coordinated observations with other space missions and ground-based observatories.

Suprathermal particles from corotating interaction regions during the first perihelion pass of Solar Orbiter

“…The Solar Orbiter mission (Müller et al 2020) was launched in February 2020 to better understand the physical processes occurring on the Sun and in interplanetary space. The first perihelion of Solar Orbiter reached a heliocentric distance of 0.52 au on 15 June 2020.…”

The source of the major solar energetic particle events from super active region 11944

“…From a space weather perspective, we must elucidate the mechanisms that drive solar flares, coronal mass ejections (CMEs), and solar energetic particles (SEPs). The recently launched Parker Solar Probe (PSP) ( 1 ) and Solar Orbiter ( 2 ) missions will investigate the Sun from a closer vantage point than ever before [within 0.1 and 0.3 astronomical unit (AU)], allowing further insights into these basic processes. Already the new measurements from PSP are fundamentally altering long-held views.…”

Solar Wind Helium Abundance Heralds Solar Cycle Onset

“…By the end of 2020, the spacecraft will have made six trips below 0.25 AU, the closest coming to within 0.2 AU of the Sun. SolO launched in February 2020 (Müller et al, 2020). Figure 6 indicates PSP's first six encounters as small yellow bars along with the time since SolO launched in light green, both in the top-right corner of the bottom panel.…”