A Soft Robot Reaches for the Stars

Picture a spacecraft circling a jagged asteroid rich in ice, minerals or clues to how the solar system formed. The terrain below is too rough for a rover. So, the spacecraft releases a swarm of small, star-shaped robots.

They wrap flexible limbs around rocks to keep from drifting away, crawl into crevices and map the surface. Some may carry sensors to study cosmic radiation, asteroid surface properties, or the asteroid's geological makeup. Their findings could one day guide a machine to collect samples, helping scientists learn how planets formed and where useful resources lie.

That is doctoral student Kristina Andreyeva's vision for STARFISH, a bio-inspired soft robot taking shape atUSC Viterbi and the USC Space Engineering Research Center (SERC). Such a mission is likely decades away. For now, researchers are tackling the fundamental challenge of teaching a soft machine to move, grip and navigate in space to perhaps diagnose and repair spacecraft.

"We're enabling operations in previously inaccessible environments," Andreyeva said. "We can one day physically get places we couldn't get to before with rigid robots."

A project revived

David Barnhart, Andreyeva's Ph.D. adviser and director at USC's Information Sciences Institute in USC Viterbi and theUSC Stevens School of Computing and AI, conceived STARFISH in 2020 to inspect welds and joints on in-orbit spacecraft. His concept was simple: launch the soft robot attached to the host vessel so it is always on hand, avoiding the need for a separate, fuel-hungry inspection craft.

Because the robot is soft and flexible, Barnhart, also a research professor in the Department of Astronautical Engineering, said it could eventually move beyond inspection to handle "limited repair or removal of objects."

The project, which had gone quiet during the pandemic, sat idle until January 2022, when Andreyeva, then a new master's student in astronautical engineering, went looking for a bio-inspired robot to work on. Barnhart handed her the shelved project on one condition: She would have to lead it and bring it back to life. She did, later carrying the work into her doctorate. Under her direction over nearly five years, roughly 30 undergraduate and master's students have cycled through the lab.

Borrowing from nature

Unlike most space robots, built from hard materials with joints that bend in fixed ways, STARFISH has a central body and four soft tentacles. The design borrows chiefly from octopus arms and elephant trunks, which bend continuously rather than only at a joint. A tentacle could move the robot, hold a tool or curl around a spacecraft or rock.

That flexibility matters in poorly mapped places. A rigid rover can become trapped or damaged in a collision. A soft robot can bend around an obstacle, squeeze into tight spaces and touch delicate equipment more safely.

"The things that nature created are unparalleled," Andreyeva said. Human-built robots, she added, remain "incredibly primitive compared to biological beings and what they can do."

STARFISH moves without motors. Inside each tentacle are wires made from a metal that contracts when heated. When electricity warms the wires, they shorten like muscles and pull the limb in several directions. When they cool, the limb straightens.

In little or no gravity, crawling requires a grip. Researchers are studying surfaces inspired by gecko feet and other ways to create controlled friction. A robot might also curl its limbs around rocks, keeping some tentacles anchored while moving others forward.

Under Andreyeva's leadership, the project has advanced from an idea to a four-limbed laboratory prototype. Her team developed a tentacle that bends in several directions, added sensing to track its position and tested a computer-control method that learns which commands will produce movement. Today, the prototype can walk-slowly-across a bench.

Andreyeva believes one tentacle could be tested in space within several years. A complete STARFISH-like robot on a mission is probably closer to a decade away.

Safer, less expensive missions

The nearer-term payoff could be inspection. A soft robot could crawl across a satellite, find a failed sensor or damaged panel and report the problem. Future versions of the STARFISH might hold themselves in place with two limbs while using another to free a wire, replace a part or help assemble structures in orbit.

Such robots could reduce risky spacewalks, catch failures early and extend the lives of costly spacecraft. Small machines could also be sent as a group; losing one would not end a mission.

The same principles could produce robots for disaster sites, hazardous-material inspections and cramped spaces on Earth. For Barnhart, that adaptability is the larger promise.

"We believe biologically inspired objects like STARFISH will play a large part in the future of space exploration," he said.

Published on October 22nd, 2026

Last updated on October 22nd, 2026