Man-made solar eclipses possible with latest satellite technology

ESA's Proba-3 mission will study the Sun creating 50 artificial solar eclipses annually, each lasting six hours.

The European Space Agency (ESA) is preparing for a groundbreaking space mission, Proba-3, which aims to create artificial solar eclipses using two satellites flying in precise formation.

This mission marks ESA's first attempt at formation flying, where the satellites will orbit the Earth in a configuration that stays within one millimeter of separation—the width of a human fingernail.

Scheduled for launch on Wednesday from the Satish Dhawan Space Centre in India, the Proba-3 mission will involve the satellites traveling a four-month journey before reaching an elliptical orbit.

The spacecraft will pass as close as 370 miles to Earth and then swing out more than 59,546 kilometres.

The Proba-3 mission aims to demonstrate new space technology by aligning the two satellites with the sun, allowing the first satellite to cast a controlled shadow on the second.

This shadow will enable instruments on the second satellite to study the sun’s corona, the outermost part of its atmosphere, in unprecedented detail.

Source: ESA

Scientists typically observe the corona during solar eclipses when the moon blocks part of the sun's light, but these events offer limited viewing time and are subject to weather disruptions.

Proba-3 promises to provide continuous access to the corona by creating 50 artificial solar eclipses annually, each lasting six hours.

The lead satellite will carry a 1.4-metre-wide disc to block the sun, turning the two satellites into a 150-metre-long coronagraph, allowing for a detailed study of the sun’s mysterious and extremely hot corona, which can reach temperatures over a million degrees Celsius.

The mission’s findings are expected to improve scientists' understanding of solar weather, solar storms, and coronal mass ejections—phenomena that can affect space technology and cause disruptions on Earth.

The Proba-3 satellites will orbit the Earth every 19.7 hours for two years, with each orbit containing six hours of formation flying. During this time, the satellites will use optical sensors, LEDs, and precision lasers to maintain alignment and ensure the exact formation necessary for the mission.

In addition to its primary objective, the mission will test techniques for servicing satellites and removing space debris, which could benefit future space operations.

The formation flying technology has the potential to revolutionize space-based observatories, enabling multiple satellites to work together to create larger instruments for various scientific studies, including climate change, planetary research, and the exploration of distant stars.