Final assembly completes the Plato spacecraft
The European Space Agency’s (ESA) Plato mission has reached a major milestone. In the Netherlands, engineers completed the final assembly by installing the combined sunshield and solar panel module onto the spacecraft. The operation, carried out in ESA’s dedicated clean room at the Test Centre, marks the last essential component being secured before the spacecraft begins its rigorous testing regime.
On 9 September, the sunshield and solar array module was carefully suspended from special lifting gear and guided to its precise position against the back of the Plato spacecraft. After a controlled alignment, the module was mounted in place. ESA’s Plato Project Manager Thomas Walloschek called the moment, “the completion of the Plato spacecraft.” He credited the excellent collaboration between ESA, the Plato Mission Consortium members, and Plato’s industrial core team for reaching this pivotal point.
The sunshield and solar panels are not mere outer features; they are critical to the mission’s success. The solar arrays collect sunlight to generate the electricity that powers Plato’s onboard electronics, while the sunshield protects the sensitive scientific instruments from direct solar glare, enabling stable operation and accurate observations.
Insights from the Plato project team
Ana Heras, ESA’s Plato Project Scientist, described the moment as special after years of planning and visualization. “Seeing the real, completed spacecraft materialize from countless drawings and simulations is truly remarkable,” she said. Plato’s distinctive design focuses on integrating advanced cameras within a compact layout optimized for its scientific goals.
At the heart of Plato’s mission is the ability to monitor more than 150,000 bright stars simultaneously with high precision. This capability is crucial for identifying terrestrial planets orbiting sun-like stars and advancing our understanding of exoplanets. To accomplish this, Plato relies on 26 highly sensitive cameras. Keeping these cameras at optimal operating temperatures is essential for performance; each camera is maintained near -80°C to minimize thermal noise and maximize detection sensitivity.
With the sunshield deployed and the solar arrays in place, the spacecraft will begin its next phase focused on verification and calibration. In a controlled test environment, engineers used a special lamp to simulate sunlight, confirming that the solar arrays deliver the correct electrical output to the rest of the spacecraft. This verification step ensured the deployment was successful and ready for further testing.
What comes next for Plato
Plato’s journey toward launch remains on track for December 2026, with an Ariane 6 rocket slated to carry it into space. However, the path to liftoff includes a demanding battery of tests designed to ensure resilience in space. The next challenges include vibration and acoustic tests that replicate the mechanical stresses of launch, where the spacecraft endures intense shaking and noise. Following these tests, Plato will be placed inside Europe’s Large Space Simulator—the largest cryo-vacuum chamber on the continent—to simulate the harsh conditions of space. Here, the mission must demonstrate flawless performance, cold stability, and reliability once in orbit.
As engineers prepare for these trials, the Plato project team remains confident that the mission’s meticulous design and thorough testing will yield valuable insights into exoplanet discovery. The mission’s success hinges on the seamless integration of its solar power system, precise scientific instruments, and robust thermal management that together will enable scientists to hunt for Earth-like worlds around distant stars.
In the months ahead, Plato’s team will continue with detailed checks, calibration, and system-level verifications, ensuring every subsystem operates in harmony. When it finally reaches space, Plato aims to illuminate new frontiers in the search for terrestrial planets, expanding our understanding of planetary systems beyond our own.
