Plato, the European Space Agency’s (ESA) mission to discover and learn about planets beyond our solar system, is about to get some assistance from SRON Netherlands Institute for Space Research. The institute recently announced that it was selected to design and build a space simulator to test and calibrate eight of Plato’s 26 cameras. SRON will start assembling the components for the actual simulator in August 2020. It should be ready by November 2020. Plato will be launched in 2026.
The most effective way to discover planets is to check for tiny variations in a star’s brightness. This reveals a planet passing in front and blocking a bit of starlight. ESA’s Plato space telescope will utilize the same method, with one particular special feature: the ability to monitor a single star, uninterrupted, for years in a row. This will allow astronomers to discover smaller planets with longer transit periods than previous exoplanet-hunting telescopes. Additionally, Plato’s sensitivity will allow scientists to extract characteristics of potential atmospheres around these planets such as cloud cover and to create a catalog for follow-up exoplanet atmospheric research.
In SRON’s design, optics will simulate a star in the sky while a radiation shield mimics the extremely low temperatures of deep space. The latter is part of another vital test to verify the correct behavior of the camera in space conditions. In the end, the simulator will determine if the cameras meet Plato requirements and will provide important calibration parameters.
Since actual flight cameras will be tested, scientists have had to design the simulator with maximum safety in mind, as a single speck of dust could potentially lead to reduced sensitivity or false detections. “Plato has a stringent requirement for contamination, even compared to other spacecraft, so we need to test the cameras in extremely clean conditions,” says Lorenza Ferrari, SRON’s project leader for Plato. “We can only have 70 parts per million of particulates on the surface. That’s 0.007 percent. With the naked eye, you can’t see under 300 parts per million.”