Swiss Technology Aboard ESA Satellites for Solar Research
Two ESA satellites carrying Swiss-made instruments successfully launched from India, advancing solar corona research through formation flying
Two ESA satellites carrying Swiss-made instruments successfully launched from India, advancing solar corona research through formation flying

"The project... is designed to reproduce an artificial solar eclipse, enabling in-depth study of the Sun’s corona."
"This vehicle has the power to send the 550kg weight of the two satellites into an elliptical orbit."
A thunderous roar tore through the skies over Sriharikota, India, this Thursday as the European Space Agency (ESA) successfully catapulted its ambitious Proba-3 mission into the ether. While the launch pad was Indian, the technology rocketing into the void carries a distinctly European—and Swiss—pedigree. The Polar Satellite Launch Vehicle (PSLV), a workhorse of the Indian Space Research Organisation (ISRO), shouldered the colossal task of hauling the mission's 550kg payload into a highly elliptical orbit.
This is no standard orbital delivery. The spacecraft are now navigating a trajectory that swings them from a mere 600 kilometers to a staggering 60,000 kilometers from Earth. This successful deployment marks a critical victory for international space cooperation, shaking off an initial delay from Wednesday to deliver a flawless Thursday liftoff. As these satellites begin their journey, they carry not just instruments, but the collective ambition of 14 nations determined to pierce the mysteries of our solar system.
Davos is world-renowned for its snowy peaks and economic forums, but today it asserts its dominance in the vacuum of space. Hidden within the satellite closest to the Sun lies "Dara" (Digital Absolute Radiometer), a technological masterpiece developed by the Davos Physical Meteorological Observatory. This is Swiss engineering at its finest: a compact, 3-kilogram instrument designed to endure the harshest environment known to man.
The development of Dara was a marathon, not a sprint, spanning over 10 years of rigorous research and calibration. While the satellite provides the platform, Dara provides the vision. It is tasked with measuring the intensity of solar radiation with absolute authority—capturing the exact amount of energy slamming into Earth's atmosphere. This isn't just data; it is the vital pulse of our climate models. The inclusion of this instrument proves once again that when precision is paramount, the world turns to Switzerland.
The Proba-3 mission is attempting a feat of engineering that borders on science fiction: formation flying with millimetric precision. In the vast, emptiness of space, these two satellites must align themselves with an accuracy that defies belief. They will maintain a distance of exactly 150 meters apart, locking into a formation so tight it effectively creates a single, giant structure out of two free-flying objects.
This high-stakes dance has a singular purpose: to manufacture an artificial solar eclipse on demand. By casting a precise shadow from one satellite to the other, the mission will block out the blinding glare of the solar disk. This allows the sensors to observe the faint, ghostly glow of the Sun's outer atmosphere—the corona—for prolonged periods. While natural eclipses offer scientists mere minutes of observation on Earth, Proba-3 promises to deliver hours of uninterrupted data, revolutionizing our understanding of solar physics.
The stakes for this mission could not be higher. The Sun's corona is a chaotic, superheated region that drives space weather, which can disrupt satellite communications and power grids on Earth. By utilizing the artificial eclipses generated by Proba-3, scientists will finally gaze into the heart of this solar activity without being blinded by the star's brilliance. The continuous measurements provided by the Swiss-made Dara instrument will offer unprecedented insight into solar irradiance fluctuations.
This mission represents a bold leap forward. With 14 countries pooling their resources and intellect, Europe is asserting its autonomy and capability in advanced space exploration. For Switzerland, the successful operation of Dara will cement its status as a critical player in the aerospace sector. As the data begins to flow back to Earth, we stand on the precipice of a new era in solar science—one where Swiss precision helps decode the fire that sustains us all.