Testing Smile’s solar arrays
On 15 May 2025, engineers checked that the solar arrays of ESA’s next space science mission, Smile, would unfold correctly in space.
On the left of the spacecraft, we see a folded-up array of solar panels: this is how the solar arrays will be stored when Smile launches into space on board a Vega-C rocket. On the right, the other solar array is fully extended, confirming to engineers that the deployment mechanism that releases the solar array works correctly.
Once in space, Smile’s solar panels will produce 850 W of power to the spacecraft’s onboard systems and scientific instruments.
Smile is currently in its ‘space environment testing’ phase at ESA’s technical heart, ESTEC, in the Netherlands. Engineers are taking the spacecraft through tough checks, needing it to pass with flying colours before being allowed out on its own. Other tests include making sure that the entire system can operate properly in the vacuum of space, that the different parts of the spacecraft don’t create too much electromagnetic disturbance for other parts, and that the violent launch won’t shake the spacecraft apart.
Smile (the Solar wind Magnetosphere Ionosphere Link Explorer) is a collaboration between the European Space Agency (ESA) and the Chinese Academy of Sciences (CAS).
[Image description: A spacecraft inside a cleanroom. The main body of the spacecraft is covered in gold-coloured thermal insulation material. To the right of the main body, there is an array of solar panels extending horizontally. The room has white walls and ceiling with structural beams and various equipment, including ladders and shelves, visible in the background.]
