South Korean researchers have published details of how RAIBO2, a quadruped robot, completed a full marathon on one battery charge in November 2024. The achievement matters because legged robots can handle stairs, rubble, slopes and other uneven terrain where wheeled machines may struggle, potentially aiding disaster response and industrial inspections.

RAIBO2 covered 42.195 kilometres in 4 hours, 19 minutes and 52 seconds, averaging 2.64 metres per second while managing 286 metres of elevation change and slopes of up to 18.4 degrees. Its performance resulted from lightweight hardware, efficient motor electronics and reinforcement-learning software; it used 1,280 watt-hours from a 2,016 Wh battery and achieved more than three times the range of comparable quadrupeds. The robot still required human operation, and fully autonomous, energy-efficient navigation remains an unresolved challenge.