Space exploration rarely follows the perfect script. Even on the most advanced missions, unexpected failures are part of the process. This is exactly what happened with the European Space Agency’s (ESA) Proba-3 mission, when one of its satellites simply stopped responding for about a month.
Now, however, the story has gained a new chapter: the probe has come back to life.
After weeks of silence, the Coronagraph satellite reestablished contact with Earth, bringing relief to scientists and rekindling expectations about one of today’s most innovative missions.
A solar eclipse created in space
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Launched in December 2024, the Proba-3 mission is made up of two satellites: Occulter and Coronagraph. Together, they accomplish something unprecedented: they create artificial solar eclipses in space.
The idea is ingenious. One of the satellites blocks direct light from the Sun, casting an extremely precise shadow on the other, which can then observe the solar corona — the outermost layer of the star’s atmosphere.
On Earth, total solar eclipses are rare and last just a few minutes. In space, with this system, scientists are able to reproduce the phenomenon in a controlled way and for much longer periods.
A month of silence in deep space
The problem began when the Coronagraph satellite suffered an anomaly in flight and stopped sending signals. For weeks, he remained silent, exposed to the extreme cold of the space environment.
Without communication, engineers did not know the exact status of the ship, which put the mission at risk.
Contact was eventually reestablished by a ground station in Spain, which was able to receive basic telemetry data, including temperature, voltage and the general state of onboard systems.
Still in safe mode
Despite the recovery, the work is far from over. The satellite is still in “safe mode”, an automatic configuration that prioritizes the ship’s survival.
In this state, the solar panel remains facing the Sun, guaranteeing energy for essential systems and allowing the battery to be recharged.
Teams are now carefully analyzing the data received to assess whether there was damage and determine when — and if — the satellite will be able to resume normal operations.
A dance of millimeter precision
The big difference of the Proba-3 mission is its precision. The two satellites fly about 150 meters apart, maintaining this separation with millimeter precision.
This extreme alignment is what makes it possible to create the “artificial eclipse” and transform the two devices into a single virtual telescope.
Each orbit around the Earth takes about 19 hours and 36 minutes, and for approximately six hours per cycle the satellites perform observations of the solar corona.
The mystery of the solar corona
The corona is one of the most intriguing regions of the Sun. Although it is furthest from the core, it is up to 200 times hotter than the solar surface — a paradox that has intrigued scientists for decades.
Furthermore, it is from this region that phenomena such as solar wind and coronal mass ejections arise, which can directly impact the Earth, affecting satellites, electrical networks and communication systems.
With more detailed observations, the Proba-3 mission can help answer these questions and improve the prediction of so-called “space weather”.
An important step towards the future of exploration
More than its scientific objectives, the mission also represents a significant technological advance. Demonstrating that two spacecraft can fly in formation with extreme precision paves the way for new forms of space observation.
The return of the Coronagraph satellite is, therefore, more than a technical recovery — it is the chance to keep alive a mission that could redefine how we study the Sun.
Now, it remains to be seen when the two partners will fly synchronized again. If all goes well, the artificial eclipse show still has a lot to reveal.
