Engineered Solar Eclipse Happens in Europe, Revealing a Fresh Perspective on the Sun
The European Space Agency (ESA) has embarked on an extraordinary mission with the launch of Proba-3, a satellite project designed to create an artificial solar eclipse that lasts for hours. This groundbreaking initiative, a collaboration with over 40 space technology firms, including three startups, promises to revolutionise our understanding of the Sun's corona.
At the heart of the Proba-3 mission are the Occulter and Coronagraph satellites. The Occulter, equipped with a 1.4-meter diameter disc, acts as a solar block, while the Coronagraph features the Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun (ASPIICS) instrument for capturing high-resolution images of the corona.
These two spacecraft fly in a precise formation, maintaining a distance of 150 meters. This alignment is crucial for creating an artificial solar eclipse, allowing the Occulter to cast an 8-centimeter shadow onto the Coronagraph’s ASPIICS instrument. The system uses advanced autonomous sensors to maintain this alignment, ensuring that the satellites remain aligned to within a millimeter without needing commands from Earth.
By positioning the Occulter in front of the Sun, an artificial solar eclipse is created. This configuration allows the ASPIICS instrument on the Coronagraph to capture detailed images of the Sun's faint corona, providing valuable insights into the solar wind and Coronal Mass Ejections (CMEs). Unlike natural solar eclipses, which are rare and brief, Proba-3's artificial eclipses can last for hours, offering extended observation periods.
The mission showcases the European Space Agency's technological advancements in precision formation flying, navigation, and positioning. These technologies are developed through ESA’s General Support Technology Programme and are pivotal for future multi-satellite missions.
Irish firm Onsemi added highly sensitive light detectors called silicon photomultipliers to measure tiny shifts in the Sun's shadow, while Dutch startup Lens R&D provided sensors that continuously track the Sun's position to within fractions of a degree. N7 Mobile, a Polish startup, contributed software for the probe's formation control systems.
Andrei Zhukov of the Royal Observatory of Belgium developed the Coronagraph's main optical sensing instrument, ASPIICS. The satellites, named Occulter and Coronagraph, orbit the Earth in formation, 150 meters apart.
The corona, the outermost part of the Sun's atmosphere, is surprisingly hot, sometimes reaching up to 2 million °C. The corona is the source of solar storms and coronal mass ejections, which can disrupt telecommunications on Earth and cause Northern Lights displays. Proba-3's achievement could change the way we study these phenomena, offering extended observation periods and high-resolution images that reveal details not observable during natural eclipses.
In a remarkable twist, startups that were once focused on consumer apps have pivoted to contribute to this mission. For instance, N7 Mobile, which was previously known for its consumer apps, has now developed computer systems that control spacecraft.
The success of Proba-3 is a significant step towards making a repeatable six-hour eclipse in orbit possible. This mission not only promises to advance our understanding of the Sun but also showcases the potential of collaborations between space agencies, startups, and private firms in space exploration.
The Occulter and Coronagraph satellites, equipped with technology from firms such as Onsemi, Lens R&D, N7 Mobile, and the Royal Observatory of Belgium's Dr. Andrei Zhukov, work in formation to create an artificial solar eclipse. This collaboration between the European Space Agency and over 40 space technology companies, including startups, is revolutionizing our understanding of the Sun's corona and solar phenomena, offering extended observation periods and high-resolution images.
