In a significant achievement, the Indian Space Research Organisation (ISRO) successfully launched the European Space Agency’s (ESA) PROBA-3 satellite aboard its trusted Polar Satellite Launch Vehicle (PSLV-C59) on its 61st commercial mission. The launch signifies another milestone in India’s growing prominence in the global space sector and highlights international collaboration in cutting-edge space exploration.
PROBA-3, short for Project for Onboard Anatomy, is a groundbreaking solar mission by the ESA. The mission is specifically designed to study the Sun’s corona, the outermost layer of the Sun’s atmosphere, with unprecedented precision. The mission consists of two spacecraft, each designed to perform a unique and interdependent role.
The Coronagraph Spacecraft (CSC), weighing 310 kg, hosts a telescope dedicated to capturing detailed images of the solar corona. The smaller Occulter Spacecraft (OSC), weighing 240 kg, plays the critical role of blocking direct sunlight to allow the telescope to study the faint outer layers of the Sun’s atmosphere. The two spacecraft are set to fly in a highly elliptical orbit, reaching an apogee of 60,500 km from Earth, with their separation maintained at an exacting 150 meters.
This mission pioneers the concept of formation flying, where two independent spacecraft operate as a synchronized system, creating a virtual “giant satellite.” The level of precision in maintaining their relative positions, down to millimeters and arcseconds, is a first in space exploration and is achieved autonomously without ground control intervention.
The PROBA-3 mission holds immense scientific promise. By observing the solar corona at a distance of just 1.1 solar radii, it will provide invaluable insights into solar phenomena. The spacecraft will capture images in visible light, ultraviolet, infrared, and polarized light, allowing scientists to map and study the Sun’s corona with remarkable clarity. Observations during the mission could also deepen understanding of solar activities that influence space weather, impacting satellites and Earth’s communication systems.
Beyond its scientific objectives, PROBA-3 represents a major technological leap. It will validate advanced guidance, navigation, and control algorithms that have the potential to revolutionize satellite docking, Mars sample return missions, and satellite de-orbiting efforts to mitigate space debris. ESA describes the mission as a “laboratory in space” where innovative techniques, such as relative GPS navigation and proximity operations in elliptical orbits, will be tested.
The mission will enter a preparatory phase, during which safety tests will be conducted to ensure collision avoidance and proper alignment of the tandem spacecraft. Once operational, PROBA-3 will demonstrate repeated acquisition, rendezvous, and formation-flying techniques during each of its orbits, marking a significant step forward in space technology.
This successful launch underscores ISRO’s capability to deliver complex international missions and ESA’s commitment to advancing solar research and space sustainability. It also serves as a shining example of global collaboration in pushing the frontiers of science and technology for the benefit of humanity.
