Scientists have unveiled a groundbreaking achievement in robotics with the first robot to complete a marathon. In November 2024, a quadruped robot named RAIBO2 ran the full 42.195-kilometer course of the Sangju Dried Persimmon Marathon in South Korea in just under four hours and 20 minutes. This accomplishment marks the first time a robot has completed such a long distance without needing to change its battery, highlighting significant progress in robotic endurance and efficiency. The significance of RAIBO2's performance extends beyond its ability to run a marathon. Researchers focused on solving a broader challenge: creating robots that can operate over long distances without excessive power use, overheating, or losing stability. Instead of focusing on individual components like larger batteries or more efficient motors, the team approached the problem as a "whole-robot system problem," emphasizing the need for integrated design and functionality. To test and refine the robot's performance, the research team ran alongside RAIBO2 during the marathon, monitoring key metrics such as voltage, temperature, battery status, and other critical data. The robot was officially registered as a participant in the event and was filmed throughout its journey, providing valuable insights into its real-world capabilities. The data collected from RAIBO2's marathon will now be used to develop a scalable product for industrial applications. While RAIBO2 was designed and built by hand, scaling the design will require ensuring its reliability across multiple units and in challenging environments. Jemin Hwang from the Korea Advanced Institute of Science and Technology (KAIST), where the robot was developed, noted that the study demonstrates how the entire robot must be designed to achieve both high performance and energy efficiency. The goal is to translate the robot's impressive laboratory performance into practical, reliable products for industrial use. The findings of this research are detailed in a paper titled "A quadruped robot designed to complete a marathon on a single battery charge," published in the journal Nature. This study represents a major step forward in the development of more practical and efficient robotic systems for real-world applications.