The ESA, in a statement, admitted that ISRO’s Polar Satellite Launch Vehicle (PSLV) is a more economical alternative to its own heavy-lift Ariane-6 and medium-lift Vega-C rockets.
“PSLV was chosen since the lift required to place the Proba-3 satellites (550 kg) on their desired highly elliptical orbit is above the Vega-C capability, and Ariane-6 would be too costly,” the space agency said in a statement.
Scheduled to take flight on December 4 from ISRO’s Sriharikota spaceport, the mission is a collaborative project involving scientists from several European countries, including Spain, Belgium, Poland, Italy, and Switzerland.
Proba-3 will also introduce the concept of “precision formation flying” in space, where two satellites will fly in tandem while maintaining an exact configuration and study the sun’s corona close to the solar rim. The Proba-3 mission is part of ESA’s ongoing efforts to explore the sun, following the success of previous missions Proba-1 (2001) and Proba-2 (2009), which were also launched by ISRO.
“ESA’s Proba-3 double satellites, lifting off Wednesday, will offer a novel view of the sun’s surrounding atmosphere, or ‘corona’. A million times fainter — but larger in expanse than the sun itself — the enigmatic corona is the source of space weather and solar wind,” ESA said in a statement.
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With an estimated cost of 200 million euros, the mission is expected to last for two years. The initial results of the mission will be revealed in March post the commissioning phase. “It involves the Occulter spacecraft, weighing 200 kg, and the Coronagraph spacecraft, weighing 340 kg. These two satellites will be 150 metres apart and block out the sun’s intense light, allowing researchers to observe the sun’s outer atmosphere for six hours,” the space agency explained.Proba-3 carries three instruments onboard, including the coronagraph named Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun (ASPIICS), which has a critical function that will aid unravel the scientific mystery: Why is the solar corona significantly hotter than the sun itself?
“It will observe the structure, dynamics and heating process very close to the sun’s surface. Refine our understanding of the interaction between the sun and its atmosphere. It will also study Coronal Mass Ejections (CMEs),” ESA said, adding that the mission has been in the making for more than 10 years.
The mission will generate approximately 50 artificial eclipses per year, each lasting six hours, offering researchers an unprecedented opportunity to examine the sun’s complex atmospheric interactions.
