Testing hot and cold

Engineers tested the entire spacecraft in typical space environment, as well as in so-called hot and cold phases.

“In the LSS, we stress-tested Plato by going to more extremes than the spacecraft will normally see in orbit,” continues Thomas. “We want to verify that the spacecraft can do what we expect it to do in harsh as well as nominal space conditions.”

During the hot phase, engineers ran all the spacecraft’s elements on full power, while the solar-panel side warmed up to 150 °C. At the same time, they made sure that the cameras, protected by the sunshield and facing the cold part of the chamber, stayed between –70 and –90 °C.

For the cold phase, temperatures were lowered across the spacecraft, and its heaters had to be powered up to prevent the cameras becoming too cold.

The tests in a space-like environment have been completed, but the analysis of the data collected while Plato was inside the LSS will continue in the coming months.

Engineers and scientists will study the information gathered to learn more about the spacecraft’s behaviour and the detailed performance of its instruments. They will use the data to improve thermal models that will be essential for predicting the cameras’ responses in detail, once Plato is flying.

And this moment is getting closer. Plato is expected to be ready for launch by the end of this year. Lift-off on an Ariane 6 is planned by Arianespace for January 2027.