The Indian Space Research Organisation (ISRO) is set to launch the European Space Agency’s (ESA) Proba-3 mission on Wednesday, December 4, using its trusted Polar Satellite Launch Vehicle (PSLV). The mission will lift off from the first launch pad at ISRO’s Sriharikota spaceport in Andhra Pradesh at 4:08 pm IST.

This mission, conducted in collaboration with ISRO’s commercial arm, NewSpace India Limited (NSIL), will carry two spacecraft, the Coronagraph and the Occulter, into a high Earth orbit. The primary objective of the Proba-3 mission is to study the Sun’s outer atmosphere, or corona, providing valuable data to ESA scientists researching solar phenomena and space weather.

The launch, marking the 61st PSLV mission and the 26th for the PSLV-XL variant, will see the 44.5-meter-tall rocket deliver the Proba-3 satellites into orbit, with a total payload of 550 kg. The satellites are expected to separate from the rocket approximately 18 minutes after launch, entering their designated high Earth orbit. The spacecraft will have an orbital period of 19.7 hours, with an apogee of 60,530 km and a perigee of 600 km from Earth.

Team of ISRO scientists offered prayers at Sri Venkateswara Swamy Temple, Tirumala, Tirupati ahead of the launch of commercial mission–Proba-3 spacecraft of the European Space Agency (ESA).

Proba-3’s mission is remarkable due to its precision formation flying technology. The Coronagraph and Occulter spacecraft will fly in tight formation, with only 150 meters separating them. This formation will enable the Occulter to block the Sun’s disc, allowing the Coronagraph to observe the Sun’s corona. This technology will allow scientists to conduct continuous solar observations, akin to a “solar eclipse on demand.” Such a capability has never been achieved on such a large scale before.

The Proba-3 mission aims to provide unprecedented insights into the Sun’s weak corona, a region far hotter than the Sun’s surface. Understanding this part of the Sun is crucial for improving knowledge of space weather, which can affect satellite communications, GPS systems, and even power grids on Earth. Solar phenomena that occur in the corona, such as solar flares and coronal mass ejections, are known to have significant impacts on these systems.

The Proba-3 mission builds on ESA’s previous Proba satellite programme, following the launches of Proba-1 and Proba-2 in 2001 and 2009, respectively. With the success of Proba-3, ESA and ISRO hope to make significant strides in solar research, as well as space weather monitoring, benefiting future space exploration missions.