Launched from Cape Canaveral, the European Space Agency’s Solar Orbiter has now sent back its first readings after the deployment of its 4.4 metre-long carbon fibre, titanium boom arm.
The ESA’s new Sun-exploring spacecraft carries ten scientific instruments, four of which measure properties of the environment around the spacecraft, especially electromagnetic characteristics of the solar wind, the stream of charged particles flowing from the Sun. Three of these ‘in situ’ instruments have sensors located on the 4.4 m-long boom arm.
Ground controllers at the European Space Operations Centre in Darmstadt, Germany, switched on the magnetometer’s two sensors (one near the end of the boom and the other close to the spacecraft) about 21 hours after liftoff. The instrument recorded data before, during and after the boom’s deployment, allowing the scientists to understand the influence of the spacecraft on measurements in the space environment.
The data we received shows how the magnetic field decreases from the vicinity of the spacecraft to where the instruments are actually deployed, this is an independent confirmation that the boom actually deployed and that the instruments will, indeed, provide accurate scientific measurements in the future.Tim Horbury of Imperial College London
Made from a combination of titanium and carbon fibre, it took the boom 30 minutes to extend out. The scientists could observe the level of the magnetic field decrease by about one order of magnitude. While at the beginning they saw mostly the magnetic field of the spacecraft, at the end of the procedure, they got the first glimpse of the significantly weaker magnetic field in the surrounding environment.
In addition to the instrument boom, three antennas were also deployed to study characteristics of electromagnetic and electrostatic waves in the solar wind. In addition to the four in situ instruments, Solar Orbiter carries six remote-sensing instruments, essentially telescopes, that will be imaging the surface of the Sun at various wavelengths, obtaining the closest-ever views of our parent star.
The combination of both sets of instruments will allow scientists to link what happens on the Sun to the phenomena measured in the solar wind, enabling them to tackle mysteries such as the 11-year cycle of solar activity, the generation of the Sun’s magnetic field and how solar wind particles are accelerated to high energies.