The launch of the European Space Agency’s (ESA) Proba-3 formation-flying satellites aboard the Indian Space Research Organisation’s (ISRO) rocket has been rescheduled for December 5, following a delay caused by technical issues. The mission aims to study the Sun’s corona through an artificial eclipse and will now lift off aboard India’s Polar Satellite Launch Vehicle (PSLV) from the Satish Dhawan Space Centre at 5:42 am EST (4:12 pm IST). This development was confirmed by ESA and ISRO.

Technical Issue Delayed Initial Launch

The Proba-3 mission, initially slated for December 4, encountered an anomaly during pre-launch checks. According to a statement from ESA Director-General Josef Aschbacher, a fault in the redundant propulsion system of the Coronagraph spacecraft was detected. This system is critical for maintaining the satellite’s orientation in orbit. The propulsion system is part of the attitude and orbit control subsystem, as stated by Aschbacher via ESA’s social media channels.

ISRO and ESA resolved the issue, ensuring the mission can proceed safely. The satellites will be launched into a highly elliptical orbit, with distances ranging from 373 miles to 37,612 miles from Earth.

Pioneering Formation-Flying Technology

Proba-3, which comprises two satellites, will demonstrate advanced formation-flying techniques. The Coronagraph spacecraft and Occulter spacecraft will align with millimetre precision at a distance of 150 metres, creating a controlled eclipse that allows prolonged observations of the Sun’s corona.
This mission will enable studies of the Sun’s outer atmosphere for up to six hours in each orbit.

Scientists hope to uncover details about the corona’s extreme heat and the acceleration of solar winds. The mission will validate technologies that could revolutionise satellite formations for future applications.