Solar Array Assembly Mechanisms for ExoMars 2022 Rover

Establishing whether life ever existed or is still active on Mars is one of the principal outstanding scientific questions of our time; it is also a necessary prerequisite to prepare for the future human exploration endeavours.

To achieve this important objective, ESA, in cooperation with Roscosmos and including a scientific instrument contribution from NASA, has launched the ExoMars mission. The ExoMars mission will search for traces of past and present life, characterize the Mars geochemistry and water distribution, improve the knowledge of the Mars environment and geophysics, and identify possible surface hazards to future human exploration missions.

Thales Alenia Space Italia was awarded the contract as prime contract for ExoMars mission and concluded Airbus Defence & Space as Lead Contractor for the Rover Vehicle.

LEONARDO was selected as supplier of the Rover Solar Array Assembly (SAA) for the ExoMars 2022 mission, and SENER was responsible, as LEONARDO subcontractor, for the SAA mechanisms and the integration and tests of the complete assembly.

The mechanisms under SENER responsibility included the six hold downs that keep in place the deployable Solar Array panels during the travel to Mars, as well as the four mechanisms that deploy the panels after landing on the red planet. The SENER responsibilities included also the integration and testing of the mechanisms and solar panels.

• Characteristics:
• The six hold downs (three on each SAA side) hold the two panel stacks in position during the travel to Mars, and after landing they release the panels by non-explosive actuation.
• After hold down release, the active hinges deploy sequentially the panels till latching in the deployed position. Once in the deployed position, the deployment mechanisms withstand passively the panel loads.
• The equipment is designed to withstand the specific environmental conditions of the Mars mission, including, among others: minimum temperature of -130 ºC (during nights on the Mars surface), maximum temperature of +125 ºC (for sterilization before the mission), dust environment (due to storms in the Mars atmosphere), panel deployment against Mars gravity and wind pressure, and fatigue in deployed configuration (due to Rover mobility loads on the Mars surface).
• The tests performed at mechanism level include sterilization, functional, vibration, shock, dust, thermal and life.
• The tests performed at SAA level include functional, deployed static load, vibration, acoustic, thermal vacuum, sterilization and deployed configuration fatigue.