Pioneering Mission to Generate Artificial Solar Eclipses with Satellites

The European Space Agency (ESA) is gearing up for an innovative space mission called Proba-3, which aims to produce artificial solar eclipses through the coordinated movement of two satellites flying in tandem.

This mission represents ESA’s inaugural foray into formation flying, where the satellites will orbit Earth with a precise distance of just one millimeter apart—about the thickness of a fingernail.

Set to launch on Wednesday from the Satish Dhawan Space Centre in India, Proba-3 will embark on a four-month journey to reach its designated elliptical orbit.

During its flight, the satellites will come as close as 370 miles to Earth before veering out over 59,546 kilometers into space.

The objective of Proba-3 is to test cutting-edge space technology by positioning the two satellites relative to the sun, allowing the first satellite to cast a controlled shadow over the second one.

This shadow will enable the second satellite’s instruments to explore the sun’s corona—the outer layer of its atmosphere—with unprecedented clarity.

Source: ESA

Scientists usually study the corona during solar eclipses caused by the moon obscuring sunlight, but these occasions provide limited observation time and can be disrupted by weather conditions.

Proba-3 is set to revolutionize observations by creating 50 artificial solar eclipses each year, each lasting six hours, providing constant access to the corona.

The lead satellite will feature a 1.4-meter-wide disc to block sunlight, effectively turning the two satellites into a 150-meter-long coronagraph and facilitating a detailed investigation of the sun’s enigmatic and extremely hot corona, which can exceed temperatures of one million degrees Celsius.

The insights gained from this mission are anticipated to enhance our understanding of solar weather patterns, solar storms, and coronal mass ejections—all of which can impact space technologies and disrupt conditions on Earth.

The Proba-3 satellites will complete an orbit around Earth every 19.7 hours for a duration of two years, with each orbit including six hours of formation flying. During this period, the satellites will employ optical sensors, LEDs, and precision lasers to ensure they maintain the necessary exact formation.

Beyond its primary goal, the mission will also evaluate techniques for satellite servicing and space debris removal, which could have significant implications for future space missions.

This innovative formation flying technology has the potential to transform space-based observatories, enabling clusters of satellites to collaborate on larger instrumentation for various scientific inquiries, from climate change assessments to planetary exploration and the investigation of distant stars.