On 27 August 2017, deep-sea researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) recovered the underwater robot Tramper, which had been taking measurements at a depth of 2435 metres for nearly 60 weeks – the first long-term mission involving a crawler under the Arctic sea ice. For the first 24 weeks, the robot took biogeochemical readings at various sites, just as it was intended to. Unfortunately, because of a broken tread, Tramper got stuck in the same place in January, though it continued to record the oxygen content in the sediment.