A joint engineering team from Samara National Research University (Russia) and Northwestern Polytechnical University (Xi’an, China) has developed a novel satellite control system that allows for rapid and highly accurate reconfiguration of satellite formations in orbit. The system employs flexible tethers to dynamically adjust the relative positions of satellites within a formation—effectively placing them “on a leash,” akin to dogs on a walk. Commands from Earth can instantly adjust tether lengths, pulling satellites closer together or letting them drift apart by precise distances.
Despite the conceptual simplicity, practical implementation demands sophisticated computational modeling and specialized hardware capable of managing the orbital tether dynamics with centimeter-level accuracy—a formidable challenge when coordinating multiple satellites traveling at orbital velocities measured in kilometers per second.
Dubbed Flex Weave (roughly translating to “flexible linkage”), the project was presented at the China International College Students' Innovation Competition 2025 and awarded a gold medal.
The research was conducted under the framework of the Sino-Russian Joint Laboratory of Space Tether Systems, jointly operated by Samara University and Northwestern Polytechnical University. Prototype tether mechanism units are currently undergoing ground-based testing on unique experimental rigs.
“The core idea of our project is to create a satellite formation whose configuration can be rapidly and precisely adjusted using flexible tethers connecting the spacecraft in orbit,” explained Sergey Ivlev, project lead and researcher at the Department of Flight Dynamics and Control Systems at Samara University. “After deployment, the satellites separate and assume a pre-defined, stable geometric arrangement—such as a star, a circle, or even a ‘Г’ shape—by precisely tuning the system’s moments of inertia and center of mass through controlled tether extension and retraction. This approach achieves centimeter-level relative positioning accuracy.”
Crucially, the system supports not only static configurations but also continuous rotation of the entire formation—a capability valuable for applications such as panoramic Earth observation or microgravity experiments.
Beyond precision and agility, Flex Weave offers a significant operational advantage: it extends satellite mission lifetimes. Conventional satellites must periodically fire thrusters to maintain orbital altitude, consuming limited propellant. Once fuel is depleted, they gradually deorbit and cease operations. In contrast, Flex Weave uses electric motors powered by solar panels to spool and unspool tethers—eliminating the need for onboard propulsion for formation maintenance. This not only prolongs active service life but also reduces satellite production costs and simplifies certification, as propulsion systems are no longer required.
Moreover, the high-precision relative positioning enabled by the system enhances capabilities in Earth remote sensing. For instance, by synchronizing radar data from two satellites in a tightly controlled formation and knowing their exact positions, advanced signal processing can synthesize imagery equivalent in resolution and detail to that of a single, massive spaceborne radar spanning the distance between the two spacecraft.
“A key component is the ultra-lightweight, ultra-thin yet extremely strong tether developed within our joint laboratory,” noted Professor Lu Hanshi, head of the Space Tether Systems Laboratory at Northwestern Polytechnical University. “Special attention has been paid to suppressing oscillations that propagate along the tether during deployment and reconfiguration. To validate the system, we have built a series of dedicated research and test benches. We believe this international recognition will further strengthen Sino-Russian collaboration in flight dynamics and space systems engineering.”
Looking ahead, the team plans to conduct an in-orbit demonstration of the technology, beginning with a minimal two-satellite formation. The satellite platform for the maiden flight is being co-developed by Russian and Chinese engineers, with orbital testing anticipated within the next few years.
