Teams coordinated the six-wheeled Charlie rover from Turin, Italy, as it crossed the Tabernas desert in Almería. The trials recreate a challenge Rosalind Franklin will face on Mars: its operators cannot respond to every move in real time.
Charlie will stay on Earth. It is a ground-based demonstrator for systems and procedures planned for ExoMars Rosalind Franklin. The test site resembles part of the work ahead, millions of kilometres away.
That communications delay sets the terms.
In 2018, ESA used the Tabernas area in Almería as an analogue site for ExoFiT-related testing of planetary exploration technologies.
Autonomous navigation is basic to the campaign. Charlie moved across Almería while teams worked remotely from Turin, not beside the rover. Communications between Earth and Mars take several minutes, so Rosalind Franklin must handle many decisions on its own.
Its cameras must spot obstacles and build a three-dimensional view of the ground. They also help calculate a safe route. The rover is designed to travel about 100 metres during a Martian sol, with stereoscopic cameras choosing suitable paths.
The Tabernas trials also test how navigation choices fit with scientific work. A route must be judged in light of the tasks the rover needs to complete.
The distance is no technical footnote. It sets the limits of control from Earth.
ESA, Airbus and other European partners took part in the campaign. Their teams tested the working sequence for planetary operations, from spotting hazards and choosing routes to conducting science through procedures tried on Earth.
Charlie is the stand-in.
It lets teams assess those systems before Rosalind Franklin leaves for Mars. The rover must link safe movement with scientific operations, even when instructions arrive late.
Sener said that after cooperation between ESA and Roscosmos ended, European industry had to complete and qualify the lander and related systems on a compressed schedule. The work is intended to keep the current target of a 2028 launch and a Mars arrival in 2030.
The mission will look beyond the surface. The current ESA ExoMars factsheet targets Rosalind Franklin for launch in 2028 and arrival at Mars in 2030.
At Oxia Planum, it will search for signs of past or possible present life in clay deposits formed when liquid water existed on Mars. That makes the site a major mission target.
The rover's most distinctive tool is a drill that can reach about two metres below the surface. Radiation and chemical processes on Mars can destroy organic molecules near the ground. Material beneath the surface may have stayed better protected for billions of years.
The drill will send samples to the rover's internal laboratory. Instruments there will examine whether Mars once had conditions suitable for life and whether traces of those conditions remain in its materials.
Oxia Planum will be studied using several tools. Rosalind Franklin carries terrain cameras and composition spectrometers, along with radar to map layers below ground and laboratory instruments to examine drilled samples.
The clay deposits formed in an environment linked to liquid water. Researchers will use them to look for chemical evidence that may have survived.
Spain's role extends beyond the testing ground. Spanish company Sener designed and manufactured the ExoMars lander's four deployable legs. It also worked on the separation system and components connected to the rover's drill.
Sener has reported progress toward qualifying the landing equipment. European partners are preparing the mission for its revised schedule.
The legs must absorb the forces of landing. Shock absorbers and sensors detect when the platform touches down. ESA has tested the systems with a full-scale lander model.
The tests included impacts on hard surfaces and materials prepared to reproduce Martian ground conditions.
Tabernas highlights the mission's hardest challenge. Mars cannot be driven like a nearby vehicle.
Charlie brings navigation and remote operations into one test before launch, alongside scientific work. The Almería campaign checks whether Rosalind Franklin can move and work safely when Earth is too far away to steer every turn.
