Supported by DARPA funding, NRL created the Robotic Servicing of Geosynchronous Satellites (RSGS) Integrated Robotic Payload (IRP). This innovative capability has been delivered to DARPA's industry partner, Northrop Grumman's SpaceLogistics, for integration with its Mission Robotics Vehicle (MRV) spacecraft bus.

"The recent completion of thermal vacuum testing marks a major milestone toward achieving the program's goal of demonstrating robotic servicing capabilities on orbit in the near future," stated Dr. Bruce Danly, NRL Director of Research. "NRL's contributions to the robotic payload are an essential part of realizing this vision, which promises to transform satellite operations in geostationary orbit, reduce costs for satellite operators, and enable capabilities well beyond what we have today. In fact, the anticipated capabilities are potentially revolutionary for both national security and civil applications."

As the designated robotic payload developer for the RSGS program, NRL undertook the task of designing, building, integrating, and testing advanced satellite servicing capabilities.

"This collaboration unlocks new servicing opportunities for both commercial and government satellites, enabling usual-close inspections, orbital adjustments, hardware upgrades, and repairs," noted Bernie Kelm, superintendent of NRL NCST's Spacecraft Engineering Division. "We've created advanced spaceflight hardware and software that will significantly enhance satellite servicing operations, including all robotic controls."

Satellites positioned in geosynchronous orbit, approximately 22,000 miles above Earth, play an essential role in military, government, and commercial communications, Earth observation, and national security.

Current space missions face challenges due to the lack of in-orbit repair or upgrade capabilities. As a result, satellites often include redundant systems and additional fuel, which add to their complexity, weight, and cost. Success in this endeavor could enable in-orbit technological upgrades, extending satellite service life, Kelm emphasized.

"The military regularly fixes aircraft, tanks, ships, and trucks that break. We upgrade aircraft and ships with the latest radars, computers, and engines," said Dr. Glen Henshaw, NRL senior scientist for Robotics and Autonomous Systems. "Satellites are the only expensive equipment we buy that can't be repaired or upgraded once they are in the field, and this costs the taxpayer money. RSGS is intended to change this situation; we intend to demonstrate that we can upgrade and repair these valuable assets using robots."

Thermal Vacuum (TVAC) Testing Process
The testing campaign exposed the robotic payload to temperature extremes and vacuum conditions similar to space, assessing all operational functions. This included tests of avionics, cameras, and lights, as well as full demonstrations of both robotic arms, covering launch lock deployments, calibrations, and tool swapping. The tests also confirmed SpaceWire communications, robotic compliance, and visual servo control modes.

"NRL's Team RSGS has spent nearly 10 years focused on the goal of completing this first of a kind, robotic servicing payload," said William Vincent, NRL RSGS program manager. "The completion of IRP TVAC represents a huge milestone and countless hours of work from an incredible group of dedicated personnel. Like sending a child off to college for the first time, shipping the IRP to Dulles is a bittersweet experience."

NRL's two-decade effort has matured the technology needed for the RSGS program. The RSGS initiative aims to safely repair and upgrade valuable satellites, which can exceed a billion-dollar cost. Future robotic satellite servicing could enable upgrades such as new electronics, propulsion, and sensors, potentially paving the way for in-orbit construction of large structures like next-generation observatories or solar power stations.

"We hope that this will eventually lead to spacecraft that are more modular and easier to maintain," added Henshaw.

Following the expected launch in 2026 aboard Northrop Grumman's MRV spacecraft bus, the robotic payload will undergo initial checks and calibrations, with full servicing missions to follow.

"We will proudly watch RSGS as it provides resilience for the current U.S. space infrastructure and takes the first concrete steps toward a transformed space architecture with revolutionary capabilities," Vincent stated.

Related Links
United States Naval Research Laboratory
Space Technology News - Applications and Research