Not satisfied with sending rovers to other worlds one at a time, NASA is sending three miniature robots to the Moon in 2024 as part of the Cooperative Autonomous Distributed Robotic Exploration (CADRE) project. The goal is to see how such explorers can work as a team without direct control from Earth.
NASA's ambition to establish a permanent human presence on the Moon is impressive, but it comes with some annoying hurdles. One that will face future astronauts for decades to come is that the Moon will suffer from a chronic labor shortage when it comes to exploration and other tasks.
The obvious way to overcome this is by using robots, however, human supervision of them on the Moon defeats the purpose and the 2.56-second round trip time delay makes remote control from Earth almost impossible for getting real work done. Projects like CADRE aim to develop an alternative, autonomous rovers and other robots that can work independently or, in the case of the new mission, as a self-organizing team.
The basic task for CADRE is to put an uncrewed commercial lander down at the Reiner Gamma region in Oceanus Procellarum. From here, three rovers, each about the size of a carry-on suitcase, will be lowered to the surface on tethers. Once unhooked, they will roll into the sunlight, deploy their solar panels, and charge their batteries.
When they reach full charge, the trio will begin a 14-day mission that must be completed by the time the sun sets at the start of the 14-day lunar night. The rovers don't have a heating apparatus and the extreme cold will permanently damage the batteries and electronics.
The real problem will be the daytime heat, which can reach 237 °F (114 °C). The rovers are built from commercial off-the-shelf parts and bespoke components, which include the latest cellphone-class processor used in NASA’s Ingenuity Mars Helicopter. According to NASA, this makes the robots robust but the clever bit is that the rovers are programmed to shut down simultaneously every 30 minutes to allow them to cool off using radiators while recharging their batteries.
While monitored by the lander, which acts as the relay control to NASA, the rovers will be given general orders like "explore this region." The rovers will then elect one of themselves as the leader based upon an algorithm and evaluate the situation. They will then act as a team to carry out their tasks in the most efficient manner possible.
NASA says that the rover team will carry out a series of tasks. The first is to stay on course while driving in formation, with their ultra-wideband radios to help them keep station and avoid obstacles. The second test will have the rovers select their own paths to explore an area of about 4,300 ft² (400 m²) and create a 3D map using stereo cameras and ground-penetrating radar that can penetrate the surface to a depth of 10 m (33 ft). In addition, the team will demonstrate how they can adapt if one rover is out of action.
"Our mission is to demonstrate that a network of mobile robots can cooperate to accomplish a task without human intervention – autonomously," said Subha Comandur, the CADRE project manager at NASA’s Jet Propulsion Laboratory in Southern California. "It could change how we do exploration in the future. The question for future missions will become: 'How many rovers do we send, and what will they do together?'"
Source: NASA