\n<\/p>\n
Construction and testing are complete on the CADRE rovers, which will map the lunar surface together as a tech demo to show the promise of multirobot missions.<\/em><\/p>\n A trio of small rovers that will explore the Moon in sync with one another are rolling toward launch. Engineers at NASA\u2019s Jet Propulsion Laboratory in Southern California recently finished assembling the robots, then subjected them to a punishing series of tests to ensure they\u2019ll survive their jarring rocket ride into space and their travels in the unforgiving lunar environment.<\/p>\n Part of a technology demonstration called CADRE (Cooperative Autonomous Distributed Robotic Exploration), each solar-powered rover is about the size of a carry-on suitcase. The rovers and associated hardware will be installed on a lander headed for the Moon\u2019s Reiner Gamma region. They\u2019ll spend the daylight hours of a lunar day \u2013 the equivalent of about 14 days on Earth \u2013 conducting experiments by autonomously exploring, mapping, and using ground-penetrating radar that will peer below the Moon\u2019s surface.<\/p>\n The goal is to show that a group of robotic spacecraft can work together to accomplish tasks and record data as a team without explicit commands from mission controllers on Earth. If the project succeeds, future missions could include teams of robots spreading out to take simultaneous, distributed scientific measurements, potentially in support of astronauts.<\/p>\n Engineers have put in long hours test-driving rovers and working out bugs to finish the hardware, get it through testing, and prepare it for integration with the lander.<\/p>\n \u201cWe have been in overdrive getting this tech demo ready for its lunar adventure,\u201d said Subha Comandur, CADRE project manager at JPL. \u201cIt\u2019s been months of nearly round-the-clock testing and sometimes re-testing, but the team\u2019s hard work is paying off. Now we know these rovers are ready to show what a team of little space robots can accomplish together.\u201d<\/p>\n While the list of tests is extensive, the most brutal involve extreme environmental conditions to ensure the rovers can withstand the rigors of the road ahead. That includes being locked in a thermal vacuum chamber that simulates the airless conditions of space and its extreme hot and cold temperatures. The hardware also gets clamped to a special \u201cshaker table\u201d that vibrates intensely to make sure it will endure the journey out of Earth\u2019s atmosphere.<\/p>\n \u201cThis is what we submit our rovers to: \u2018shake\u2019 to simulate the rocket launch itself and \u2018bake\u2019 to simulate the extreme temperatures of space. It\u2019s very nerve-wracking to witness in person,\u201d said JPL\u2019s Guy Zohar, the project\u2019s flight system manager. \u201cWe\u2019re using many carefully selected commercial parts on our project. We expect them to work, but we\u2019re always a little worried when we go into testing. Happily, each test has ultimately been successful.\u201d<\/p>\n Engineers also performed environmental testing on three hardware elements mounted on the lander: a base station that the rovers will communicate with via mesh network radios, a camera that will provide a view of the rovers\u2019 activities, and the deployer systems that will lower the rovers to the lunar surface via a fiber tether fed slowly out from a motorized spool.<\/p>\n Putting Code to the Test, Too<\/strong><\/p>\n Meanwhile, engineers working on CADRE\u2019s cooperative autonomy software have spent many days in JPL\u2019s rocky, sandy Mars Yard with full-scale versions of the rovers called development models. With flight software and autonomy capabilities aboard, these test rovers showed they can accomplish key goals for the project. They drove together in formation. Faced with unexpected obstacles, they adjusted their plans as a group by sharing updated maps and replanning coordinated paths. And when one rover\u2019s battery charge was low, the whole team paused so they could later continue together.<\/p>\n The project conducted several drives at night under large flood lamps so the rovers could experience extreme shadows and lighting that approximate what they\u2019ll encounter during the lunar daytime.<\/p>\n After that, the team performed similar drive tests with flight models (the rovers that will go to the Moon) in a JPL clean room. When the spotless floor there proved a bit slippery \u2013 a texture different from the lunar surface \u2013 the robots got out of formation. But they stopped, adjusted, and proceeded on their planned path.<\/p>\n \u201cDealing with curveballs \u2013 that\u2019s important for the autonomy. The key is the robots respond to things going off plan, then they replan and are still successful,\u201d said JPL\u2019s Jean-Pierre de la Croix, CADRE principal investigator and autonomy lead. \u201cWe\u2019re going to a unique environment on the Moon, and there will, of course, be some unknowns. We\u2019ve done our best to prepare for those by testing software and hardware together in various situations.\u201d<\/p>\n Next, the hardware will ship to Intuitive Machines for installation on a Nova-C lander that will launch atop a SpaceX Falcon 9 rocket from NASA\u2019s Kennedy Space Center in Florida.<\/p>\n A division of Caltech in Pasadena, California, JPL manages the CADRE technology demonstration project for the Game Changing Development program within NASA\u2019s Space Technology Mission Directorate in Washington. CADRE is a payload under NASA\u2019s CLPS (Commercial Lunar Payload Services) initiative, which is managed by the agency\u2019s Science Mission Directorate. The agency\u2019s Glenn Research Center in Cleveland and its Ames Research Center in Silicon Valley, California, both supported the project. Motiv Space Systems designed and built key hardware elements at the company\u2019s Pasadena facility. Clemson University in South Carolina contributed research in support of the project.<\/p>\n For more about CADRE, go to:<\/p>\n<\/p>\n