A blue box, a cubic metre of Mars-like sand, a rock, a fully-functional model of the Mars ‘Mole’ and a seismometer – these are the main components with which the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is simulating the current situation on Mars. After its first hammering operation on 28 February 2019, the DLR Heat and Physical Properties Package (HP³), the Mars Mole, was only able to drive itself about 30 centimetres into the Martian subsurface. DLR planetary researchers and engineers are now analysing how this could have happened and looking into what measures could be taken to remedy the situation. “We are investigating and testing various possible scenarios to find out what led to the ‘Mole’ stopping,” explains Torben Wippermann, Test Leader at the DLR Institute of Space Systems in Bremen. The basis for the scientists’ work: some images, temperature data, data from the radiometer and recordings made by the French Seismic Experiment for Interior Structure (SEIS) during a brief hammering test conducted on 26 March 2019.