CMU’s robot has recently been named Iris, in part to honor Siri Maley, a former master’s student in mechanical engineering who was a leader and an early champion of the robot’s development (Iris is Siri spelled backwards). Also, the robot’s main sensors are two video cameras and, in cameras, an iris is a diaphragm that controls the amount of light that enters the lens. Finally, Duvall noted, an iris is a flower known for withstanding extreme environments, just as the robot will on the moon.
Duvall said usually about 40 students — primarily undergraduates — were involved each semester, though the ranks swelled to more than 70 this semester.
"The fact that it’s going into space has been a strong pull for student involvement," she explained.
As a student project, the robot went through many design changes, in part because each succeeding group was eager to put their own twist on it, Duvall said. But building a light robot also required some difficult design choices.
One major change was the number of wheels. Iris began as a two-wheeled robot supported in the rear by a tail that dragged along the surface. The idea was that the lightweight tail replaced heavier wheels. But the tail caused so much drag that the team decided to add two wheels, foregoing the weight advantage in favor of saving energy, Duvall said.
Nick Acuna, a sophomore mechanical engineering major, joined the project as a first-year student, though he doubted he could contribute much that was useful. Assigned to the wheel design group, he discovered a way to make carbon composite wheels that "worked really, really well." It enabled the wheels, which resemble bottle caps, to be both lighter and stiffer. By the end of last summer, he had been elevated to mechanical lead.
"This project is pretty important to me,”"Acuna said, explaining that he enjoys going "all in," focusing his drive on a single thing. In high school, wrestling was his focus. Now, with Iris, "I’ve slowly gotten to that same mindset." Working on CMU’s first space program is nothing short of inspiring, but also humbling, he added.
"It lets you dream about what you can accomplish in the future, if you’re already doing this as a student," he explained. "I know a lot of great people have come through this project. We have the privilege of being the team in the semester when we bring it all to fruition.
"All these giants have touched it and we’re the ones who get to see it through to the end."