One week since its launch, the European Space Agency's Solar Orbiter has sent to Earth its first data, providing confirmation that its deployed instrument is working well. The craft is on its way towards the Sun, and although the entirety of the mission is still more than 1.5 years away, the team need to make sure everything is working as it should.
The Solar Orbiter's magnetometer is attached to a 4.4-meter (14.4-foot) boom so that the spacecraft doesn’t interfere with the measurements. The data the control center received shows the dramatic difference in readings that can occur when the sensitive instrument is moved away from Solar Orbiter's main body, with measurements dropping by a factor of 10 in some cases.
Solar Orbiter will be used to study the flow of the solar wind, the stream of electrically charged particles coming from the Sun and its magnetic property. To do so, it has to measure the emissions from the spacecraft first.
“We measure magnetic fields thousands of times smaller than those we are familiar with on Earth,” Tim Horbury of Imperial College London, principal investigator for the Magnetometer instrument (MAG), said in a statement. “Even currents in electrical wires make magnetic fields far larger than what we need to measure. That’s why our sensors are on a boom, to keep them away from all the electrical activity inside the spacecraft.”
The MAG has two sensors, one near the end of the boom and one closer to the spacecraft. The instrument will have to be calibrated before the true science collecting can begin. The mission has four instruments collecting the data “in-situ” and six remote-sensing instruments that will image the surface of the Sun. Each instrument will be tested in turn until the end of April, and the team hope to begin gathering data in May.
“Seeing these data come in is wonderful because Solar Orbiter is all about relating the experience of being out there in the wild solar system to the places on the Sun that drive all its “weather”. So these data are the first part of the puzzle that we’re going to be putting together over the next few months – and years,” Dr David Williams, one of the three instrument operations scientists for Solar Orbiter, told IFLScience.
Solar Orbiter is not going to be the closest spacecraft to the Sun, that will be NASA’s Parker Solar Probe in a few years, but it will provide the closest images of the surface of the Sun, including for the first time its poles. Parker has no camera directed at the Sun because it gets so close that any kind of opening in the heat shield would cook the whole spacecraft.