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Solar Orbiter



The European Space Agency (ESA) Solar Orbiter mission will study the Sun from a highly elliptical orbit getting as close as 0.28 AU (42 million km), from which it will use a suite of instruments to make high-latitude observations of the Sun and heliosphere, including the magnetic field, energetic particles, solar wind, and transient phenomena. Solar Orbiter has as its primary science objectives: to study the drivers of the solar wind and the origin of the coronal magnetic field; to determine how solar transients drive heliospheric variability; to learn how solar eruptions produce the energetic particles that fill the heliosphere; and to study how the solar dynamo works and drives connections between the Sun and the heliosphere.

Solar Orbiter comprises a 2.5 x 3.0 x 2.5 meter box-shaped bus with two solar panel wings spanning 18 meters to supply power. Total launch mass is 1800 kg. There is a 4.4 meter instrument boom and three 6.5 meter antennas protruding from the spacecraft body. A carbon fiber composite, titanium layered solar shield covers one side of the spacecraft. The shield has apertures for various instruments. The spacecraft is 3-axis stabilized to keep the heat shield oriented towards the Sun. Telemetry is dual X-band through steerable medium and high-gain antennas. Low gain antennas are used in the launch and early orbit phase, and are available for backup.

Solar Orbiter carries two types of instruments, in-situ instruments making direct measurements of the heliospheric environment, and remote sensing instruments, which view the Sun and heliosphere from a distance. The in-situ instruments comprise an Energetic Particle Detector (EPD), a Magnetometer (MAG), a Radio and Plasma Waves sensor (RPW), and a Solar Wind Plasma Analyser (SWA). The remote-sensing instruments are an Extreme Ultraviolet Imager (EUI), a Coronagraph (METIS), a Polarimetric andHelioseismic Imager (PHI), a Heliospheric Imager (SoloHI), a Spectral Imaging of the Coronal Environment (SPICE), and an X-ray Spectrometer/Telescope (STIX). Total scientific payload mass is 209 kg.

Solar Orbiter launched from Cape Canaveral Air Force Station on 10 February 2020 at 04:03 UT (11:03 pm, February 9 EST). The spacecraft launched on an Atlas 5-411 (AV-087) into a short Earth parking orbit followed by injection into an elliptical heliocentric orbit. The first perihelion will be in June 2020. The mission will use six gravity assist maneuvers: one Earth flyby (26 Nov 2021) and five Venus flybys (27 Dec 2020, 8 Aug 2021, 03 Sep 2022, 18 Feb 2025, and 24 Dec 2026) during the 7-year nominal mission. This will bring the orbit to an inclination of 25 degrees with a perihelion of 0.28 AU, an aphelion of 0.91 AU, and a period of 168 days. It will make 14 perihelion passes during the nominal mission. If a three year extended mission is approved, Solar Orbiter will make three more Venus flybys (17 Mar 2028, 10 Jun 2029, 2 Sep 2030) to bring the inclination to 33 degrees. The extended mission will involve 8 more perihelion passes.

For more information, see the ESA Solar Orbiter website:

Image credit: ESA

Alternate Names

  • 45167
  • SolarOrbiter

Facts in Brief

Launch Date: 2020-02-10
Launch Vehicle: Atlas V
Launch Site: Cape Canaveral, United States
Mass: 1800 kg

Funding Agency

  • European Space Agency (International)


  • Solar Physics

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. Daniel MuellerProject ScientistEuropean Space
Dr. Teresa Nieves-ChinchillaDeputy Project ScientistNASA Goddard Space Flight
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