Replica Martian soil set to aid development of ESA rovers

A team from Cranfield University’s centre for automotive technology has recreated Martian soil using a finely ground form of silicon dioxide known as silica flour in a project funded by ESA.

One of a number of soil types characterised by the current NASA Mars exploration rovers (MERs), Spirit and Opportunity, the so-called ‘soil surrogate’ will be used to help recreate the terrain of the Martian surface and conduct a number of experimental tests on Earth prior to sending the ESA rover (ExoMars) to Mars in 2018.

NASA performed similar experiments when developing its rovers to enable characterisation of the physical environment on Mars, to maximise the performance of its vehicle and to minimise the possibility of the rover getting stuck in the soil.

These experiments were repeated on Mars and involved wheel trenching and slipping, creating ruts that were used to reliably infer the soil physical properties.

The Cranfield group decided to simulate the most complex of the Martian soils identified, which meant there were a number of strict criteria around grain size (greater than 50 per cent of the sample had to be within a very narrow size range), relative density, cohesion and angle of internal friction.