Sun storms in stereo

Launched on 25 October, NASA’s two-year STEREO mission aims to capture 3D images of massive eruptions from the Sun, known as coronal mass ejections (CMEs). Image sensors from UK-based e2v will be aboard the simultaneously orbiting twin spacecraft to capture the phenomena.

The resulting images will provide the world’s first 3D view of the Sun/Earth relationship from sideways on, and will also help to predict when space weather events will affect the Earth.

STEREO is the space agency’s Solar Terrestrial Relations Observatory, which forms part of the Solar Terrestrial Probes programme. While one spacecraft will fly ahead of the Earth in its orbit around the Sun, the second will lag behind so the stream of energy and matter approaching the Earth from the Sun can be studied in 3D.

e2v supplied 12 flight model charge-coupled device (CCD) image sensors and eight engineering models for STEREO. Ten of the models will fly with STEREO, five CCDs in each spacecraft.

The e2v devices are astronomical CCD42-40 models, back-illuminated for high sensitivity, and mounted in a custom package to improve alignment, flatness and thermal control in the instrument.

They will record events in the extreme ultraviolet spectrum to support the study of solar mass ejections in stereo. The spacecraft will be in place to start capturing images three months into the mission.

The company worked with NASA and ESA, and supplied sensors for the Gaia project and for the Mars explorer.