Europe’s ambitious mission to photograph the Sun’s outer atmosphere, or corona, has hit a serious snag.
The European Space Agency (Esa) has lost contact with one of the two spacecraft powering its Proba-3 mission, and scientists are now racing to find out what went wrong.
WHAT HAPPENED TO THE PROBA-3 CORONAGRAPH?
In early February, an anomaly onboard Proba-3’s Coronagraph spacecraft triggered a chain reaction that led to the progressive loss of attitude control. In simpler terms, the spacecraft lost its sense of direction in space.
Because the spacecraft’s solar panel was no longer facing the Sun, the onboard battery started to discharge quickly. This caused the spacecraft to enter survival mode, when minimal electronics are active and data transmission to the ground is interrupted.
Think of it as the satellite switching to the bare minimum to stay alive, cutting off all communication in the process.
WHY DOES PROBA-3 NEED TWO SPACECRAFT?
Proba-3 is not your ordinary space mission. It consists of two satellites, the Coronagraph and the Occulter, which work together to create artificial solar eclipses in orbit, allowing scientists to study the Sun’s corona, its outermost layer, in extraordinary detail.
The two spacecraft must fly in extremely precise formation, separated by roughly 150 metres, to pull off this feat.
CAN ESA FIX THE CORONAGRAPH?
Mission teams are investigating how the Occulter spacecraft, which remains healthy and operational, could safely approach the Coronagraph and observe its orientation in space to support recovery efforts.
Since launch in December 2024, Proba-3 has completed more than 60 accurate formation flying orbits, which involve multiple spacecraft coordinating their paths to maintain specific, relative positions while orbiting Earth.
Proba-3 has gathered hours of science data per orbit, marking a landmark achievement in solar research.
Scientists are hoping this is not the end of the road. The root cause of the anomaly remains under investigation.
