Launch date set for ESA’s Solar Orbiter mission ‘to face the sun’

In October 2019, after undergoing final testing in Germany, the Solar Orbiter was on its way to NASA’s Cape Canaveral launch site in Florida. Now, the countdown to the launch is just a matter of a couple of weeks away, reports the European Space Agency (ESA).

The Solar Orbiter mission, with strong NASA participation, is dedicated to solar and heliospheric physics. It will address big questions in Solar System science to help us understand how the Sun creates and controls the heliosphere, the giant bubble of plasma that surrounds the whole Solar System and influences Earth and the other planets within it.

An Antonov cargo plane transported the spacecraft and essential ground support equipment from Munich, Germany, to Florida, landing at the Shuttle Landing Facility at Kennedy Space Centre on 1 November. From there the satellite and equipment travelled by road to the AstroTech Space Operations facility where it has undergone more testing.

ESA

Just as important, the Solar Orbiter will join NASA’s Parker Solar Probe, which is already engaged in its mission. Launched from Cape Canaveral on a Delta IV Heavy rocket on August 12, 2018, the Parker Solar Probe carries a smaller payload than Solar Orbiter but it goes closer to the Sun.

Even though the Solar Orbiter and Parker Solar Probe have their own missions, by working together, the two spacecraft will collect complementary data sets that will allow more science to be collated from the two missions than either could manage on its own.

The Solar Orbiter spacecraft (seen in the background) is fuelled with propellants and oxidiser in the hazardous processing facility at Astrotech. The spacecraft contains hydrazine and MON-3 – a mixture of oxides and nitrogen. Thrusters are used to control the attitude of the spacecraft once in space.

ESA

Facing the Sun
The Solar Orbiter will be launched on top of an Atlas V 411- and will be live-streamed from 05:00 CET at t https://www.esa.int/esawebtv. After launch, Solar Orbiter will take approximately 3.5 years, using repeated gravity assists from Earth and Venus, to reach its operational orbit,

Initially, the spacecraft will be in an elliptical orbit with perihelion 0.28 au and aphelion 0.9 au. Over the course of the 7-year mission, the spacecraft will use additional gravity assists from Venus to raise its inclination from 0° to 25°, allowing it a better view of the Sun’s poles. This should give the Solar Orbiter an operational orbit with a period of 168 days and a minimum perihelion radius of 0.28 AU.

An illustration of the structure of the Sun

Kelvinsong

The main scientific activity will take place during the near-Sun encounter and high-latitude parts of each orbit, with different science goals planned for each orbit. Science data will be downlinked for eight hours during each communication period with the ground station.

The science payload of Solar Orbiter comprises both remote-sensing and in situ instruments. The in situ instruments will operate continuously, while the complete suite of ten instruments will become operational around the spacecraft’s closest approach, and at the minimum and maximum heliographic latitudes.

Here’s a quick look overview of the mission in our new factsheet.

ESA on Twitter

Instruments aboard Solar Orbiter
The Solar Orbiter will be carrying a payload consisting of four heliospheric in-situ instruments, and six solar remote-sensing instruments.

First, the heliospheric instruments: They include a Solar Wind Analyser (SWA), used to measure solar wind properties and composition, and an Energetic Particle Detector (EPD), used to measure suprathermal ions, electrons, neutral atoms, and energy particles.

C/P image of the coronal transient of 5 May 1980, taken at 11:38 UT.

NASA Goddard Space Flight Center

Also included in the heliospheric instrument group is a Magnetometer (MAG). it will provide detailed measurements of the magnetic field. The fourth instrument is the Radio and Plasma Wave analyzer (RPW). This is used to measure magnetic and electric fields at high time resolution.

One of the remote-sensing instruments onboard the Solar Orbiter is a coronagraph. It is a telescopic attachment designed to block out the direct light from a star so that nearby objects – which otherwise would be hidden in the star’s bright glare – can be seen.

Then, there are a number of different kinds of imagers, including a Polarimetric and Helioseismic Imager (PHI), an EUV full-Sun and high-resolution Imager (EUI), and an EUV spectral Imager (SPICE). Last, but not least is the Spectrometer Telescope for Imaging X-rays (STIX).