European engineers are putting the landing system for ESA’s ExoMars Rosalind Franklin rover through a demanding series of drop tests as preparations continue for the mission’s planned landing on Mars later this decade.
To validate the performance of the descent module’s landing legs, teams from Thales Alenia Space and Airbus have been repeatedly dropping a full-scale structural model of the four-legged landing platform onto simulated Martian surfaces at the ALTEC facilities in Turin, Italy. The tests are designed to assess stability and impact resistance under a range of realistic touchdown scenarios.
The landing legs are a critical component of the ExoMars descent system, working alongside parachutes and braking engines to ensure a safe arrival on the Red Planet. The lightweight, deployable legs are interconnected and fitted with shock absorbers to withstand impact forces, while maintaining stability even if the spacecraft lands at an angle or encounters uneven terrain such as rocks.
Over the course of more than a month, engineers conducted dozens of vertical drop tests, varying both the height and speed of impact by small increments. The platform was dropped onto hard surfaces as well as soft beds filled with Mars-analogue soil, matching the chemical composition of the sandy regolith used to test the Rosalind Franklin rover’s mobility.
Benjamin Rasse, ESA’s team leader for the ExoMars descent module, said the tests are focused on preventing the platform from tipping over on landing. He noted that confirming stability under worst-case conditions is essential to protecting the rover and ensuring mission success.
The campaign also verified the performance of the touchdown sensors integrated into each landing leg. These sensors detect contact with the surface and trigger the shutdown of the descent engines. Rapid communication is critical, as any delay could allow rocket plumes to disturb the soil beneath the lander, potentially damaging or destabilising the platform. Engineers reported that the system is meeting the requirement to shut down the engines within 200 milliseconds of touchdown.
Further testing is planned over the coming months, including higher-speed drops onto a moving sledge to simulate tilted landings. Data collected from high-speed cameras, accelerometers, lasers and sensors will be fed into computer models and algorithms to simulate a wide range of Mars landing scenarios.
