Matthew Jordan ESA, NASA, ULA

Solar Orbiter Set to Give a Better View of the Sun

Featured Image: Solar Orbiter is removed from it’s shipping container in November 2019. (Image credit: NASA/Kim Shiflett)

The ESA Solar Orbiter mission is set for launch from Cape Canaveral aboard a ULA Atlas V booster on Sun. Feb. 9 at 11:03 PM local time (EST). This mission is a long awaited heliospheric science mission which is seeking to answer several several questions.

  • What drives the solar wind and how does space weather impact Earth?
  • What controls the Sun’s 11-year activity cycle?
  • How is the magnetic field generated inside the Sun?
Artist’s rendition of Solar Orbiter. (Image credit: NASA)

To answer these questions, Solar Orbiter will take a 3.5 year journey, using several gravity assist flybys of Earth and Venus to place it in an orbit that has a perihelion (closest approach to the sun) of 0.28 AU (26 million miles) and aphelion (farthest point from the sun) of .9 AU (83.6 million miles). At its closest approach, Solar Orbiter will be closer to the sun than Mercury. It orbit will begin with a standard inclination in line with the ecliptic (the inclination of the planets) and will then begin using gravity assists to raise its inclination to 25 degrees. If the mission is extended past its seven-year duration, this inclination could be raised to 34 degrees. This will give humans the first views of the solar north and south poles. Solar orbiter will be on a 5-month orbital period.

Solar Orbiter’s planned trajectory over it’s mission duration. (Image credit: ESA)

To accomplish this mission and give answers Solar Orbiter has four in situ and six remote sensing instruments.

In situ instruments are:

  • Solar Wind Analyser (SWA): To measure solar wind properties and composition
  • Energetic Particle Detector (EPD): To measure suprathermal ions, electrons, neutral atoms, as well as energetic particles in the energy range from few keV/nuc to relativistic electrons and ions up to 100 MeV (protons) and 200 MeV/nuc (heavy ions)
  • Magnetometer (MAG): it will provide detailed measurements of the magnetic field 
  • Radio and Plasma Wave analyser (RPW): To measure magnetic and electric fields at high time resolution

Remote sensing instruments are:

  • Polarimetric and Helioseismic Imager (PHI): To provide high-resolution and full-disk measurements of the photospheric magnetic field
  • EUV full-Sun and high-resolution Imager (EUI): To image various layers of the solar atmosphere
  • EUV spectral Imager (SPICE): To provide spectral imaging of the solar photosphere and corona, characterise plasma properties at the Sun
  • Spectrometer Telescope for Imaging X-rays (STIX): To provide imaging spectroscopy of thermal and non-thermal solar X-ray emission from 4 to 150 keV
  • Coronagraph (Metis): To provide simultaneous UV (121.6 nm), and polarised visible light imaging of the corona
  • Heliospheric Imager (SoloHI): To image quasi-steady and transient flows of the solar wind (US provided)

Scientists have been awaiting this mission since 2012. There have been several delays in the launch, which was originally proposed for 2017 and then 2019. Stay tuned to Next Horizons Spaceflight for updates and launch photography!