ISRO to launch Proba-3 to simulate solar eclipse and unlock secrets of the Sun- Details

ISRO is set to launch the Proba-3 mission, which aims to create an artificial solar eclipse to unlock new insights into the Sun’s corona and improve space weather predictions.

ISRO will launch ESA's Proba-3 mission to create an artificial eclipse and study the Sun's corona. (ESA)

The Indian Space Research Organisation (ISRO) is gearing up to launch the European Space Agency's (ESA) Proba-3 mission, which aims to create an artificial solar eclipse in space. Set to lift off on December 4 aboard the Polar Satellite Launch Vehicle (PSLV), this mission seeks to enhance the study of the Sun's corona using a pair of coordinated satellites.

Proba-3 consists of two satellites: the Occulter Satellite (OSC) and the Coronagraph Satellite (CSC). The OSC features a 1.4-meter occulting disc designed to block sunlight, creating a shadow that is just eight centimeters wide at a distance of 150 meters. Positioned within this shadow, the CSC carries a telescope with a 5-centimeter aperture to observe the Sun's corona.

Both satellites will work in tandem, maintaining precise formation using advanced flying techniques. Their positioning will occur at the apogee of their elliptical orbit, around 60,000 kilometers from Earth, where gravitational forces are minimal. This helps reduce the fuel needed for station-keeping, ensuring efficient operation.

Why Studying the Solar Corona is Crucial

Studying the solar corona is crucial for understanding solar dynamics and space weather. Solar storms and coronal mass ejections can cause disruptions on Earth, impacting power grids and communication systems. However, observing the corona is extremely difficult due to the intense brightness of the Sun, which is about a million times stronger than the corona itself. Traditional coronagraphs have been limited by diffraction, which hampers their ability to study the inner corona. Natural solar eclipses provide ideal conditions, but they are rare and only last for a few minutes.

Proba-3's Impact on Solar Observations

Proba-3's artificial eclipse will change this by offering a continuous observation window of six hours during each 20-hour orbit. This represents a significant increase in observation time, providing scientists with much-needed insight into the region between the low and high corona. In addition to studying the corona, the mission will test advanced spaceflight techniques, such as formation flying, rendezvous, and convoy flying, while also minimizing fuel consumption by alternating between active flying and passive drifting phases.