On January 12, 2025, scientists from the European Space Agency (ESA) initiated an ambitious project named Proba-3. The mission was successfully launched by India using a Polar Satellite Launch Vehicle (PSLV) at 11:34 CET (10:34 GMT) from the Satish Dhawan Space Centre.
According to ESA's official website, the mission aims to create an artificial solar eclipse using two spacecraft flying in a highly precise formation. This setup will enable deeper observations of the solar corona, which is a hundred times dimmer than the sun itself.
"In short, this is an experiment in space to demonstrate a new concept and new technology that is technically challenging," stated Damien Galano, Proba-3 project manager at ESA.
Proba-3 consists of two spacecraft, the Occulter and the Coronagraph, separated by approximately 150 meters in an elliptical orbit of 600 x 60,000 kilometers. The Occulter will cast a shadow on the Coronagraph for six hours during specific periods, allowing observations of the solar corona that are difficult to achieve without atmospheric interference.
"This system will allow us to observe the structure and dynamics of the solar corona in visible light," said Joe Zender, ESA mission scientist. "We hope to gain a better understanding of the initiation of these physical phenomena to model them more effectively and understand their physics, as well as their impacts on satellites and Earth."
The data collected from Proba-3 aims to enhance models predicting solar wind and coronal mass ejections (CMEs), which are crucial for satellite operations and ground-based systems. The mission also seeks to test precision formation flying technology, potentially paving the way for future applications such as space-based interferometry and exoplanet detection.
Proba-3 opens up possibilities for future space technology applications, including monitoring space weather and developing precision flight systems for other space missions. The success of this mission could lay the groundwork for the use of satellites in formation for various purposes, such as planetary mapping, exoplanet atmospheric observation, and satellite servicing in orbit.
The Proba-3 initiative involves over 40 companies from 14 ESA member countries and required more than a decade of development. The choice of PSLV from India was a compromise regarding launch costs and mission requirements. The mission is expected to last two years, with the satellites returning to the atmosphere after five years, underscoring ESA's commitment to sustainable space exploration.