India and European space agencies have come together for the launch of Proba-3, the world’s first precision formation flying mission, also known as the Sun mission. This mission aims to study the Sun’s corona, closer to the solar rim than ever before. The Proba 3, or the Sun mission is the newest addition to ESA’s family of in-orbit demonstration missions.
What is the Proba-3 mission?
The European Space Agency‘s Proba-3 mission is focused on demonstrating technologies and techniques for highly precise satellite formation flying. It will consist of two small satellites launched together, which will then separate and fly in a coordinated manner, to create an artificial eclipse. This groundbreaking mission is seen as a stepping stone for future multi-satellite missions that function as a single virtual structure.
Proba-3 stands as a collaborative milestone in space technology, developed over more than a decade with contributions from 14 European countries and 29 industrial partners. The mission is funded through ESA’s General Support Technology Programme, with significant contributions from companies such as Sener, Redwire, and Airbus Defence and Space.
How does Proba-3 work?
The two small satellites, operating as a ‘large rigid structure,’ will be launched together in a highly elliptical orbit (600 x 60,530 km, with an inclination of approximately 59 degrees) in a stacked configuration. They will separate about 18 minutes after liftoff, with the flight control team at ESA’s ESEC facility in Redu, Belgium, expecting to receive the first signal roughly 15 minutes later.
The separation, projected to be accurate to within a single millimeter (about the thickness of an average fingernail), will create a nearly 150-meter-long solar coronagraph to observe the Sun’s faint corona. The two satellites will align precisely with the Sun, 150 meters apart, so that one casts a carefully controlled shadow onto the other
According to ESA, unlike natural solar eclipses, which last less than ten minutes and occur infrequently, Proba-3 will offer a remarkable 100-fold increase in study time. The mission will generate around 50 ‘eclipses’ per year, each lasting six hours, providing researchers with an unparalleled opportunity to study the Sun’s complex atmospheric interactions.
When will it be launched?
The Sun mission, led by the Indian Space Research Organisation (Isro), is scheduled for launch on December 4, at 16:08 IST or 10:38 GMT, aboard a PSLV-XL rocket from the Satish Dhawan Space Centre in Sriharikota, India.
The launch could be watched via ESA Web TV and on Isro’s YouTube channel which will begin around 15:38 IST or 10:08 GMT.
The term ‘Proba’ comes from the Latin phrase ‘Let’s try.’ It refers to a series of experimental missions, starting with Proba-1, followed by the Sun-observing Proba-2 in 2009, and the wide-swath Earth-observing Proba-V for Vegetation in 2013.