After four and a half years of silence, a French satellite appeared

In 2018, a team of astronomers from the Paris Observatory for Space Studies and the Laboratory of Astrophysical Instruments (LESIA) sent a nanosatellite, PicSat, into space. Its mission was to send valuable information to Earth about the exoplanets orbiting the star. Beta Pictures. However, after four years of operation and a smooth launch, nearly two months after its launch, the satellite had plunged into silence, from one minute to the next… for more than four and a half years. It only came back to life in June 2022, when the mission was abandoned for years.

“Within two months of operation, it was a discovery for the whole team, we were starting with very little. We were able to take it in our hands, control it, install it, test the different systems, and two months later, on March 20, it went silent. We tried everything to try and reconnect it. It was very sad, after four and a half years of work”, testifies to Sylvester Lacourt, astrophysicist at the Paris Observatory.

The satellite was tracked by observatories that deal with all space debris, “We knew it was intact, but it stopped giving us news.” In France, The law prohibits sending satellites without a way out of orbit when they are no longer useful. According to this law, a satellite must leave its orbit within twenty-five years. On small satellites similar to nanosatellites, in low orbit, they are small enough with air friction, after ten years, they disintegrate in the atmosphere. After the PicSat science mission failed, the team of astronomers relied on the fact that it would disintegrate within ten years.

To everyone’s surprise, an amateur astronomer reported PicSat activity on Twitter in June 2022.

“By default, the satellite, when restarted, goes into survival mode. It sends a small broadcast every 10 seconds in which there is a PicSat name, encoded in bits, along with rotation speed, battery charge, and small basic remote metrics. In these small messages , the name of the satellite is in the code. We decoded all messages and it was him. It seems to be in good condition, and the battery seems to be off.

The team does not yet have an explanation for PicSat’s silence and temporary shutdown of the signal, but it is currently working on several threads.