A proposed Mars rover will undergo its most ambitious test to date in remotely guided explorations of a Mars-like desert in South America, scientists said.

The test in the desolate Atacama Desert in northern Chile will be overseen remotely from Britain, providing experience for future missions to the Red Planet, the European Space Agency reported from its Paris headquarters Friday.

An early prototype of the six-wheeled ExoMars rover will be put to the test in Chile fitted with prototypes of three of its scientific instruments, the agency said.

"This field trial is about optimizing the use of typical instruments and equipment aboard a Mars rover and generating a set of commands for the rover to execute the following day," ESA project overseer Michel van Winnendael said.

The rover's remote overseers in Britain will first downlink data then prepare a set of commands for the next day the rover will then carry out on its own, project scientists said.

Images of the test site taken from an unmanned aerial vehicle to simulate the overview from a Mars orbiter will be sent to the remote operators, they said.

"Since this is a rehearsal of a planetary exploration scenario there is an inevitable degree of uncertainty in the sequence of events," van Winnendael said.

"Nature is very inventive in presenting situations which were not fully anticipated by those who conceived the mission," he said. "That's why we find it important to do field tests in a fairly representative environment."