The European Proba-3 mission, launching on December 4 from India, aims to explore the solar corona using two spacecraft operating in tandem. The mission will enable artificial eclipses for extended observation, enhancing our understanding of the Sun’s outer atmosphere and its extreme temperatures. This innovative approach builds on previous technologies and is supported by India’s reliable PSLV-XL launcher, showcasing cost-effective advancements in space exploration. Live coverage will be available via Isro and Esa channels.
Exploring the Solar Corona: The Proba-3 Mission
Prepare for a groundbreaking journey as the European Proba-3 mission is set to launch on Wednesday, December 4, from the Satish Dhawan Space Centre in Sriharikota, India. The mission will embark on an ambitious flight spanning over 60,000 km from Earth, with a launch time slated for 4:08 PM local time (11:38 AM Paris time). Space enthusiasts can catch the live launch via the Indian Space Research Organisation (Isro) on their YouTube channel, as well as on the European Space Agency (Esa) website, featuring live commentary in English.
Innovative Tandem Flight for Solar Observation
The Proba-3 mission is designed to delve into the solar corona, the outermost layer of the Sun’s atmosphere. This ethereal region, which stretches millions of kilometers thick, remains largely invisible to the naked eye and even standard telescopes due to the Sun’s overwhelming brightness. Only during total solar eclipses has its existence been revealed, originally observed by early astronomers. The significant breakthrough came in the 20th century when Bernard Lyot developed the first coronagraph, enabling astronomers to study the Sun’s atmosphere more effectively.
Building upon Lyot’s innovation, the Esa has crafted a mission involving two spacecraft that will operate in unison over a two-year period, executing a highly elliptical orbit. This impressive maneuver will see the two satellites maintaining a distance of 144 meters apart with extraordinary millimeter-level accuracy, akin to the thickness of a fingernail. The first spacecraft, named ‘Occulter,’ will feature a 1.40 m diameter shield designed to block the Sun, thereby casting a shadow on the second spacecraft, ‘Coronagraph.’ This will allow the Coronagraph to examine the solar corona within the penumbra created by the Occulter.
Unlike natural total solar eclipses, which only occur every 18 months and last mere minutes, the Proba-3 mission will facilitate artificial eclipses, enabling continuous observation of the solar corona for six hours at a time. The spacecraft will complete an orbit around Earth in just 19 hours and 36 minutes, providing unprecedented data on the solar environment.
The ultimate goal of this mission is to enhance our understanding of the solar corona and complement the findings of other missions like Solar Orbiter and Parker Solar Probe. Astronomers are eager to decode the enigma of the solar corona’s extreme temperatures, which soar to millions of degrees Celsius despite the comparatively cooler surface temperature of just 6000 degrees. This puzzling phenomenon may be linked to magnetic activities, as noted by Raphaël Rougeot, a systems engineer at the Esa.
Choosing the Indian PSLV-XL launcher for this mission was a strategic decision driven by its reliability and cost-effectiveness, making it ideal for a technology demonstration with a limited budget. India’s space program has gained considerable traction since its inaugural lunar mission in 2008, efficiently utilizing existing technologies and employing a skilled workforce, allowing them to minimize costs effectively.