ESA’s Solar Orbiter mission has finished its tests in Europe. On October 17th 2019, the probe was displayed for the last time in Europe, at the testing centre IABG.
After having been constructed in the United Kingdom at Airbus Stevenage, it has been during the last year in Germany, not far from Munich, undergoing essential tests, such as those for the deployment mechanism, and its resistance to launch vibrations, as well as to the extreme temperatures and the emptiness of space.
After having formally passed the last qualification revue, it is now ready for transfer aboard an Antonov cargo plane on October 31st 2019 to Cap Canaveral, before its launch foreseen for February 6th 2020.
Among the measurement instruments, a radio receiver
The mission target being the Sun, Solar Orbiter will carry th RPW readio receiver, an instrument designed by an international consortium under the scientific leadership of Milan Maksimovic, CNRS research director, at the Laboratory for space studies and instrumentation of the Paris Observatory.
The development and construction of the instrument were done by an integrated LESIA/CNES team with contributions from two other laboratories : the LPC2E (at Orléans) and the LPP (at Palaiseau).
The design and the performance of the RPW experiment will enable one to obtain for the first time very accurate measurements at low frequencies of the electric fields in the internal solar, in the ambient solar wind, and also across interplanetary shocks.
At higher frequencies, thermal noise spectroscopy will furnish accurate measurements electron temperatures and densities, while in the radio domain the instrument will measure the emissions associated with the injection into the solar corona of energetic electrons produced during eruptions.
To know more about the Sun-Earth connection
Once launched, the Solar Orbiter probe will describe an elliptical path around the Sun, coming as close to it as 42 million km.
The parts of the space vehicle which are facing the Sun will have to resist temperatures of above 500° C - because of the solar radiation which is 13 times higher than that received by satellites in Earth orbit, while other parts of the probe will be in shadow at -180 ° C.
The Solar Orbiter mission is vital if one is to know more about the Sun-Earth connection.
We live in a giant plasma bubble created by the Sun, and which surrounds the whole Solar System. In the heart of this bubbble, we are potentially at the mercy of Space meteorology and the solar storms which can perturb terrestrial electrical systems. Solar Orbiter will deepen our understanding of the Sun and its internal heliosphere via the two following key procedures :
In situ measurements in the solar wind at distances never before achieved, using specific dedicated instruments (foreseen minimum perihelion of 0.28 au, i.e.,between 60 solar radii and the solar surface, 42 million km) ;
Remote observations of the Sun with, among other advantages, the best ever spatial resolution (70 km/pixel).
Solar Orbiter will be launched by an Atlas V 411 rocket furnished by NASA. Launch is currently planned for the early hours (UTC) of February 6th 2020.
Once in space and for many years to come, the probe will use the gravitational attraction of Venus and of the Earth to direct the sound above the solar poles, thus furnishing new view of our star, including the first ever images of the solar poles.
Thanks to its set of complementary instruments, the probe will be able to study the local plasma environment surrounding the probe, and to obtain solar data from a distance, by combining information about solar activity and the spatial environment of the internal solar system.
