A group of final-year mechanical engineering students from Johns Hopkins University have designed a prototype rock grinder that could one day play a pivotal role in space construction and exploration by transforming asteroid dust into useful materials.
The students—Jonik Surprenant, Jacob Hammond, Grace Nockolds, and Zahari Stoimenov—were tasked with a unique challenge: to engineer a device that could crush asteroid rock, or regolith, into a fine, uniform powder in a zero-gravity environment. While breaking up rocks isn’t a new concept, the absence of gravity presented entirely new obstacles.
“The first month of our project, we looked at all of these crushing mechanisms that work on Earth—and basically had to throw them out,” explained Surprenant. “They don’t work in space.”
Commissioned by aerospace start-up Karman+, which is focused on extracting raw materials from asteroids, the student team set out to create a compact and energy-efficient device that could operate aboard spacecraft. The ultimate goal is to make in-space processing of asteroid material viable, potentially replacing the costly task of launching heavy supplies from Earth. The powdered regolith could be converted into satellite fuel, building material, or components for solar panels.
The students’ invention, nicknamed “Wall-E,” is a cube-shaped prototype roughly a foot in length. It features a system of spinning blades and applies mechanical force to grind rock without relying on gravitational pull. Regolith enters via a collapsible, accordion-style entry point and is then fed into a grinder modelled after an ice shaver. Once crushed, the dust is sifted and stored for future use.
One of the project’s most innovative components is a three-axis rotating frame, designed to mimic the disordered motion typical of microgravity conditions. “That was one of the defining moments for me,” said Rich Bauernschub, who co-leads the senior design course with associate research professor Stephen Belkoff. “They had this eureka sort of presentation.”
The team will unveil their prototype on 29 April at the university’s annual Design Day, hosted by the Whiting School of Engineering. Though the device isn’t space-ready just yet, Karman+ believes it will significantly inform the design of a version they plan to send into orbit.
Jesse Miller, a 2018 Hopkins graduate now working as an engineer at Karman+ and advising the student team, said, “As a company, we aim to deliver asteroid regolith to supply the space economy. But first, we need to grind it—and that’s where this project at Hopkins comes in.”
With asteroid mining edging closer to reality—NASA and Japan’s space agency having already returned samples—Karman+ has scheduled its first mission for 2027, aiming to eventually process material directly in space.
For the students, who are all also varsity athletes, the experience has been more than just an academic exercise. “We’re not just building a gadget—we’re defining a process,” Nockolds said. “It’s real engineering, with a real client, working on something no one’s done before.”
Miller added that mentoring the project has been a full-circle moment for him. “I remember my own senior design project as the most valuable experience of my time at Hopkins. It’s just awesome to watch this team work,” he said.
