A few days ago, the Proba-3 spacecraft reached another major milestone — successfully completing not one, but two full formation flying orbits! These orbits were made possible by a combination of relative GPS measurements and the Visual Based System (VBS), which includes both the Wide Angle and Narrow Angle Cameras.

But that wasn’t the only highlight of the test. For the first time in flight, the team activated the Fine Lateral and Longitudinal Sensor (FLLS) — a precision laser instrument located on the Occulter spacecraft, designed to take Proba-3’s formation flying accuracy to the next level.

There was just one small catch: the Occulter spacecraft didn’t quite know where to point the laser. Due to the intense vibrations endured during launch, the exact orientation of the laser had slightly shifted, and needed to be calibrated directly in orbit.

To solve this, the Proba-3 team designed a clever spiral-shaped search pattern, carefully calculated on the ground and uploaded to the spacecraft. This pattern allowed the laser beam to scan the expected area up to locating its target — the Corner Cube Retro-Reflector (CCRR) on the Coronagraph spacecraft.

Then came the moment of truth. After a few dozens minutes of intense expectation, the control room burst in cheers as the LOCKED signal was received from the telemetry, confirming that the laser had successfully found its target.

This marks a giant leap forward for the mission: the FLLS is now providing real data, which will be used to calibrate the unit and prepare for its integration into the formation flying control loop.

With each new achievement, Proba-3 comes even closer to unlocking precision formation flying, critical for solar coronagraphy. Stay tuned for more updates!