A few hours ago the Solar Orbiter space probe blasted off atop an Atlas V rocket from Cape Canaveral. After about 53 minutes, it successfully separated from the rocket’s last stage and began the long journey that will take it up to about 42 million kilometers from the Sun. A little later it deployed its solar panels and started communicating with the mission control center.

The Solar Orbiter mission, sometimes called SolO, is a collaboration between ESA and NASA to try to get some answers to questions related to solar activity. The Sun not only supplies energy that’s crucial for life on Earth but also generates the heliosphere, the bubble in which the density of the solar wind is greater than that of interstellar matter. The heliosphere is an environment influenced by the Sun in various ways still not fully understood.

Ten different instruments will be used for detections of various solar emissions which include magnetic fields, high-energy particles, and plasma. They will help to understand the origin of the solar wind and the magnetic field in the solar corona, the variability of the heliosphere’s size, the energetic particles produced in the solar flares and how the solar dynamo works with its consequences on the heliosphere.

The Solar Orbiter space probe started a long journey that, in about 1.5 year, will take it within the planet Mercury’s orbit, where it will begin its main scientific mission. Its final orbit will be very elliptical, so much that the point farthest from the Sun will be close to the Earth’s orbit. The expected duration is 7 years, during which the orbit’s inclination will be varied to get out of the ecliptic plane and get a view of Sun’s poles as well.

When it’s inside Mercury’s orbit, with the point closest to the Sun about 42 million kilometers from it, the Solar Orbiter space probe will be exposed to an environment full of radiation, 13 times higher than that received on Earth. It can be very hot with parts exposed to the Sun that will have to withstand temperatures even higher than 500° Celsius. A heat shield was especially designed to protect it. Its solar panels were also built specifically to operate in that environment using technologies already developed for another ESA mission, BepiColombo and in particular the Mercury Planetary Orbiter (MPO) now traveling to the planet Mercury.

The Solar Orbiter space probe’s work will proceed together with that of another solar probe now on its road, NASA’s Parker Solar Probe, in a synergy in which the data obtained from the two missions will be put together to obtain better results.