The European Space Agency’s Proba-3 mission reached an unprecedented milestone. In 2024, it did so with two spacecraft flying in such precise alignment that they were able to simulate a total solar eclipse. This incredible moment would have taken place after the satellites assumed orbits fairly proximal to Earth, as close as 372 miles (600 kilometers). Simultaneously, they reached heights over 37,282 miles (60,000 kilometers) out. The mission’s primary goals included taking incredible pictures of the sun’s corona and developing new technology to prepare for future space exploration.
The two spacecraft operating as part of the Proba-3 mission are designed to fit perfectly together. One satellite is used to mimic the moon during a solar eclipse, blocking the bright parts of the sun. The second spacecraft, fitted with a specialized camera, takes pictures of the resultant artificial eclipse. This configuration enables scientists to observe the sun’s corona, which is crucial for understanding solar dynamics and their impact on space weather.
Technological Innovations in Space
Beyond these exciting scientific goals, Proba-3 is notable because of its technical innovations. The spacecraft literally flies through space at incredible speed! It moves at speeds ranging from 5,400 mph (8,690 kph) to stunning 79,200 mph (127,460 kph). Even at these extreme speeds, they achieve a remarkable precision of about one millimeter.
The two satellites are separated by 492 feet (150 meters). They can regulate themselves without any human being involved. This represents an important leap in the development of autonomous space operations. It enables accurate control and real-time monitoring of their positions throughout the mission.
Understanding Space Weather
So in addition to its stunning images of the sun’s corona, Proba-3 has a key space weathering application. The mission observes high-energy particles that the sun ejects into space, which can have detrimental effects on Earth-orbiting satellites and other technologies. Through studying these solar happenings, scientists will be able to more accurately forecast space weather events and help reduce the risks they pose.
The Proba-3 mission is more than just picturesque images. It provides key information about solar activity that can directly affect Earth’s environment. Grasping these dynamics is key to maintaining and advancing the security and resilience of satellite communications and navigation systems.
Successful Imaging of the Solar Corona
In June 2025, Proba-3 fulfilled one of its main goals by managing to take an image of the sun’s corona. The photos reveal the stunning complexity of this tenuous outer layer of the sun, and scientists now have fresh data from which to work.
This milestone serves to underscore the success of the ASPIICS coronagraph on Proba-3. The imagery shot in this simulation provides never-before-seen perspectives to improve existing models of how the sun behaves.
“The solar corona, as viewed by Proba-3’s ASPIICS coronagraph.” – ESA/Proba-3/ASPIICS/WOW algorithm