Level 1 - Absolute Beginner
A robot dog ran a full marathon. A marathon is a very long race. It is about 42 kilometres.
The robot is called RAIBO2. It was built in South Korea. It ran the race on one battery. It did not stop to charge.
The robot finished in four hours and twenty minutes. Scientists wrote about it in a famous journal called Nature.
- robot
- a machine that can do jobs by itself
- marathon
- a very long running race of 42 kilometres
- battery
- a small box that stores power
- charge
- to fill a battery with power
- race
- a contest to see who is fastest
- finish
- to come to the end
- scientist
- a person who studies the world
- journal
- a magazine for science studies
Level 2 - Elementary
A four-legged robot from South Korea has run a full marathon on a single battery charge. The robot is called RAIBO2, and it was built by a team at KAIST, a science university. A paper about it was published in the journal Nature on September 23, 2026.
The robot ran the Sangju Gotgam Marathon on November 17, 2024. It covered 42.195 kilometres in 4 hours, 19 minutes and 52 seconds. It used about 1,280 watt hours of power, and the team says it could have gone about 65 kilometres.
The team had failed once before. In September 2024, an earlier robot ran out of battery at about 37 kilometres, because it kept changing speed to avoid other runners. A company started by KAIST researchers, called Raion Robotics, now wants to build such robots for real jobs.
- four-legged
- having four legs
- university
- a school for advanced study
- paper
- a written scientific report
- covered
- travelled a distance
- watt hour
- a unit that measures energy
- failed
- did not succeed
- researcher
- a person who studies something to learn new facts
- company
- a business
Level 3 - Intermediate
A quadruped robot built at South Korea's KAIST has completed a full marathon on a single battery charge, and the result is now documented in the journal Nature, in a paper dated September 23, 2026. The machine, RAIBO2, covered the 42.195 kilometres of the Sangju Gotgam Marathon on November 17, 2024, in 4 hours, 19 minutes and 52 seconds.
The run consumed roughly 1,280 watt hours from a 16s10p lithium-ion pack, and the researchers estimate that the leftover energy would have carried it about 65 kilometres in total. An earlier version had run flat near the 37 kilometre mark in September 2024, after repeatedly changing speed to work around other runners, which wasted energy.
The lab, led by Professor Hwangbo, argues that long-distance endurance is not a question of any single component such as a better battery or motor. It is a problem of the whole machine, from the gait and the controller to the way weight and heat are managed. Raion Robotics, a startup spun out of the lab, is now working on commercial, mass-produced quadrupeds meant to work for long periods in real environments.
- quadruped
- an animal or robot that walks on four legs
- document
- to record in writing
- consume
- to use up
- lithium-ion
- a common type of rechargeable battery
- endurance
- the ability to keep going for a long time
- component
- one part of a larger machine
- gait
- the way in which a body moves when walking or running
- startup
- a new business, often built around a new idea
Level 4 - Advanced
When RAIBO2, a quadruped developed at KAIST, crossed the finish line of the Sangju Gotgam Marathon in 4 hours, 19 minutes and 52 seconds, it did something no legged robot had been documented doing: covering the full 42.195 kilometres on a single battery charge. The accomplishment, which took place on November 17, 2024, reached a wider audience this autumn with a paper in Nature dated September 23, 2026.
The feat is instructive precisely because an earlier attempt failed. In September 2024 a prior version ran flat around the 37 kilometre mark, having squandered energy by repeatedly accelerating and braking to negotiate other competitors. By contrast the successful run drew about 1,280 watt hours from a 16s10p lithium-ion pack, and the researchers calculate that the reserve would have sufficed for roughly 65 kilometres.
The team's central claim is conceptual: endurance is an emergent property of the entire system, not the product of a single superior part. Gait, control software, thermal behavior and mass distribution must be tuned together. The lab's spinoff, Raion Robotics, is now pursuing mass production of machines designed to operate for long stretches outside the laboratory, a step that would turn a spectacular demonstration into an industrial tool.
- accomplishment
- something achieved successfully
- instructive
- providing useful lessons
- squander
- to waste something valuable
- negotiate
- to find a way past an obstacle
- sufficed
- was enough
- emergent
- arising from the interaction of many parts
- thermal
- relating to heat
- spinoff
- a new company created from an existing organization
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