By Linda Herridge
NASA's John F. Kennedy Space Center
Digging on the Moon is a hard job for a robot. It has to be able to collect and move lunar soil, or regolith, but anything launching to the Moon needs to be lightweight. The problem is excavators rely on their weight and traction to dig on Earth. NASA has a solution, but is looking for ideas to make it better. Once matured, robotic excavators could help NASA establish a sustainable presence on the Moon under the Artemis lunar exploration program, a few years after landing astronauts on the surface.
Engineers have tested various configurations of a Moon-digging robot called RASSOR – short for Regolith Advanced Surface Systems Operations Robot – in a large lunar simulant sand box at NASA’s Kennedy Space Center in Florida. Now, NASA is asking the public to help design a new bucket drum, the portion of the robot that captures the regolith and keeps it from falling out. The regolith can then be transported to a designated location where reverse rotation of the drum allows it to fall back out.
RASSOR’s current bucket drums are hollow cylinders positioned on either end of the robot, with scoops around the circumference of the cylinders. The robot digs in opposing ends toward the other, which balances the excavation forces and makes it easier to dig.
NASA’s RASSOR Bucket Drum Design Challenge is open through April 20, 2020. The challenge, sponsored by NASA’s Space Technology Mission Directorate (STMD), seeks a better shape for RASSOR’s bucket drum and baffling, or sheet metal inside of it that can capture and hold more regolith. GrabCAD, a website people can join and post 3D models of almost anything, hosts the challenge and eligible individuals, with an idea can submit original designs that have not been previously published, exhibited or put into production for this important part of RASSOR.
“We’ve held challenges on GrabCAD in the past and they were very successful,” said Jason Schuler, a robotics engineer in the Exploration Research and Technology Programs at Kennedy. “As a repository for computer-aided design, the platform helps us reach professional designers, engineers, manufacturers and students outside of the space industry who may have an idea that could benefit NASA.”
Successful designs for this competition will have a fill ratio of higher than 50%, which means the design’s interior volume will be more than half full with regolith when it reached the maximum amount it can hold.
“With RASSOR, we’re no longer relying on the traction or the weight of the robot. It is possible to excavate on the Moon or Mars with a really lightweight robot,” Schuler said.
“RASSOR is excavation and transportation all in one, but we’d like to improve the design.”
At the end of the competition, the design entries will be judged on a set of criteria, including width of the scoops, bucket drum mass, diameter and length, volume of regolith captured and practicality of the design. In addition to the CAD files, entries must include a short description of how the design works.
A total of $7,000 will be awarded for the top five submissions.