The first batch of 20 charge-coupled devices (CCDs) to be flown on ESA’s PLATO space observatory was accepted for delivery by ESA in mid March. This is an important milestone on the road to creating our groundbreaking spacecraft that will detect Earth-sized exoplanets in orbit around distant stars. The remaining 84 detectors will be delivered in further batches before the end of 2020.
PLATO will utilize highly sensitive light detectors – rather like advanced versions of the CCDs used in digital cameras – assembled in 26 telescopes, all mounted on a single satellite platform. Each telescope feeds 4 CCDs that have been specially designed and produced by Teledyne e2v in Chelmsford, UK.
PLATO combined cameras will have an extremely wide field of view, covering a total area on the sky of approximately 2250 square degrees – as a comparison, the full Moon spans only about 0.2 square degrees on the sky.
Depending on the science operations plan that is eventually selected, PLATO will observe between 10 and 50 per cent of the sky from its orbital location around the L2 Lagrange point, 1.5 million km away from Earth in the anti-Sun direction.
Each PLATO CCD produces an image of 20 megapixels (or Mpixels), so that each telescope comprise about 80 Mpixels, resulting in a full satellite total of 2.12 gigapixels (Gpixels). This is over twice the equivalent number for ESA’s Gaia mission, which currently features the largest camera ever flown in space.
The large format of the CCDs – approximately 8 cm × 8 cm per detector – will result in a total optically sensitive surface of 0.74 square metres. The detectors will work at a temperature lower than -65°C to maximize their sensitivity.
Most of the CCDs will take measurements every 25 seconds, but eight of them, fitted in two ‘fast’ telescopes, will make measurements of brighter stars every 2.5 seconds.
“The delivery of the first detectors at this time is important because it secures the early availability of one of the key elements of the whole mission,” said Bengt Johlander, the PLATO Payload Manager for ESA.
More than the CCDs, ESA is providing the spacecraft, the mission operations, and parts of the science operations. The PLATO Mission Consortium, funded by national agencies, is providing the payload and contributes to the science operations.
For more details see ESA press release: