On December 4, 2024, the European Space Agency (ESA) will attempt to create an artificial solar eclipse, with significant contributions from the Indian Space Research Organisation (ISRO). The mission, known as Proba-3, aims to study the Sun's corona using two satellites in a precise formation flight.
The satellites, named the Occulter Satellite (OSC) and the Coronagraph Satellite (CSC), will operate at an altitude of approximately 60,000 kilometers above Earth, where gravitational forces are minimal. This positioning will help reduce the propellant needed for station-keeping.
The OSC features a 1.4-meter occulter disk designed to block sunlight, casting an 8-centimeter wide shadow at a distance of 150 meters. Within this shadow, the CSC will utilize a telescope with a 5-centimeter aperture to observe the corona. This setup allows scientists to study the corona, which is typically obscured by the Sun's brightness, which is a million times more intense than the corona itself.
The Proba-3 mission represents ESA's first attempt at precise formation flying, with the satellites maintaining a formation accuracy of less than one millimeter. The launch will occur from the Satish Dhawan Space Centre in Sriharikota, India, aboard ISRO's Polar Satellite Launch Vehicle (PSLV).