The Solar Orbiter Mission has taken off on its mission to explore the Sun. Here’s the technology behind this groundbreaking mission.
On February 10, 2020, the engines of an Atlas V rocket ignited at Cape Canaveral, launching the Solar Orbiter spacecraft on its way to explore the mysteries of our local star. This mission, headed by the European Space Agency (ESA) now heads to the Sun, bringing with it a diverse array of technologies designed to study our stellar parent.
This mission will become the first spacecraft to ever study the polar regions of the Sun in detail, which are (so far) hidden from observation from Earth-based astronomers or any previous spacecraft.
“Once it has reached its target orbit, the spacecraft will approach Earth’s host star to within 42 million kilometers [26 million miles] and will also be able to provide detailed images of the Sun’s polar regions for the first time,” explains Carsten Henselowsky, Solar Orbiter Project Manager at the German Aerospace Center (DLR).
Over the course of a planned seven-year-mission, the Solar Orbiter will collect data on the Sun’s electric field, energetic particles streaming from the Sun, and seismic waves traveling through our local star.
Something is in the Air
The heliosphere is the atmosphere of the Sun, a bubble of plasma surrounding our parent star. By studying this layer of the Sun, researchers hope to better understand space weather, which can affect electronic communications and other electronics on Earth. These events could also endanger space travelers carrying out operations outside their vehicle, an activity becoming more common as human explorers begin to explore the Solar System.
“As humans, we have always been familiar with the importance of the Sun to life on Earth, observing it and investigating how it works in detail, but we have also long known it has the potential to disrupt everyday life should we be in the firing line of a powerful solar storm. By the end of our Solar Orbiter mission, we will know more about the hidden force responsible for the Sun’s changing behavior and its influence on our home planet than ever before,” said Günther Hasinger, Director of Science at ESA.
What the Solar Orbiter has in Common with Horseshoe Crabs
The spacecraft as a whole has a mass of 1,800 kg (3,970 pounds on Earth), and stretches 18 meters (59 feet) in length. As it orbits the Sun, the Solar Orbiter will endure temperatures ranging from -180 Celsius (-292 Fahrenheit) to over 500 C (930 F). This high temperature is 13 times greater than heating experienced by satellites in Earth orbit.
Journeying to the Sun requires a significant amount of energy. To obtain the momentum needed to enter solar orbit, the spacecraft will carry out several close encounters with Venus and Earth before reaching its final orbit in 18 months. Following one of these close encounters with Venus, the spacecraft will slingshot out of the ecliptic plane of the solar system (the region at which the planets travel), headed for an orbit around the poles of the Sun.
Local measurements of the region between Earth and the Sun will be taken during throughout the journey. At the end of its 42 million kilometers (26 million miles), remote sensing instruments will begin to relay data to Earth.
Ten instruments are now on their way to the Sun on a journey to better understand solar science. Each of these instruments, like the 10 optical receptors of horseshoe crabs, examines light at different frequencies in an effort to better understand what it needs to know.
Energetic Particle Detector (EPD): This instrument will study highly energetic particles streaming from the Sun as the solar wind as they pass by the spacecraft, examining the composition of the solar wind, and recording how it changes over time.
Extreme Ultraviolet Imager (EUI) will create series of images of different layers of the atmosphere of the Sun — the solar chromosphere, transition region, and corona.
One of the great mysteries of the Sun is that the corona (atmosphere) of the Sun is hotter than its surface — almost as if the area around a campfire were hotter than the fire itself. This phenomenon will be examined by EUI, which could allow researchers to connect data collected about the solar wind to activities on the Sun.
Heliospheric Imager (SoloHI): Light scattered by electrons in the solar wind will be recorded by SoloHI, as this instrument searches for unusual activity that could signal a coronal mass ejection, a powerful eruption from the surface of the Sun.
Magnetometer (MAG): The magnetic field of the Sun extends far beyond the Sun, and MAG will examine how this field changes over time, providing data on how the solar corona is heated, and how energy is transported along the solar wind.
Metis: Coronagraph: Capable of taking simultaneous images in visible and ultraviolet light, this instrument will reveal the behavior of the solar atmosphere at distances ranging from 487,000 km (304,000 miles) to over 2,150,000 km (1,340,000 miles) from the surface of the Sun. Researchers hope that studying this region will allow them to study how space weather is formed before dispersing into the Solar System.
Multi Element Telescope for Imaging and Spectroscopy (METIS) This instrument will image the solar corona at both extremes of ultraviolet wavelengths, looking for signs of both lower- and higher-energy activities in this region surrounding the Sun.
Polarimetric and Helioseismic Imager (PHI): Developed by the Max Planck Institute for Solar System Research (MPS) and the Kiepenheuer Institute for Solar Physics (KIS) in Germany, this instrument will study velocities of material in the photosphere (outer visible shell) of the Sun, as well as the magnetic fields of our local star.
“It will also produce velocity maps of the movement of the photosphere that will allow helioseismic investigations of the solar interior, in particular the convective zone,” the ESA reports.
Radio and Plasma Waves (RPW): Several antennas and sensors will work in unison, measuring the variation in electromagnetic fields surrounding the Sun. This is the only instrument aboard the Solar Orbiter capable of carrying out in situ studies (measuring the area immediately surrounding the spacecraft) as well as remote sensing of activity happening on and near the Sun.
Solar Wind Plasma Analyser (SWA): Bulk properties of the solar wind, such as density, velocity, and temperature of the solar wind will be examined by the SWA, as well as the composition of particles of which it is composed.
Spectral Imaging of the Coronal Environment (SPICE): Designed to examine extreme ultraviolet wavelengths of light, this device will study the properties of plasma within the solar corona.
Spectrometer/Telescope for Imaging X-rays (STIX): This instrument will view our parent star in X-rays, which can be produced in hot plasma. When solar flares occur, STIX will provide data on the timing, location, and intensity of these events, potentially providing new information on the nature of the solar wind.
Walking on the Sun
“In less than a hundred years, we have found a new way to think of ourselves. From sitting at the center of the universe, we now find ourselves orbiting an average-sized sun, which is just one of millions of stars in our own Milky Way galaxy.” — Stephen Hawking
Following launch, the spacecraft sent a signal back home from low Earth orbit, confirming its successful separation from the upper stage of the launcher. This message was received at a ground station in New Norcia, Western Australia.
In addition to its unique studies, the Solar Orbiter will also conduct measurements in coordination with NASA’s Parker Solar Probe, launched in 2018. While Parker approaches much closer to the Sun than its European partner, it is not equipped with instruments allowing it to directly measure the Sun. Their respective orbits, nearly at right angles to each other, allows each craft to study behavior all over the Sun.
“Solar Orbiter is the newest addition to the NASA Heliophysics System Observatory, joining Parker Solar Probe in an extraordinary adventure to unlock the biggest mysteries of the Sun and its extended atmosphere,” said Holly Gilbert, NASA Solar Orbiter Project Scientist.
Together, the new Solar Orbiter, together with the Parker Solar Probe, promise to lead to a radical transformation in our understanding of our parent star, and the solar system in which we reside.
James Maynard is the founder and publisher of The Cosmic Companion. He is a New England native turned desert rat in Tucson, where he lives with his lovely wife, Nicole, and Max the Cat.
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