Rescuing satellites is harder than it looks. A growing space junk problem will make doing so more important

Rescuing satellites is proving to be a complex and high-stakes endeavor, especially as the amount of orbital debris continues to grow. On July 3, 2026, a commercial robotic spacecraft named LINK was launched on an urgent mission to salvage NASA’s Neil Gehrels Swift Observatory, which had begun descending toward Earth due to dwindling fuel reserves. Built by Katalyst Space Technologies, LINK aims to grasp the aging telescope and maneuver it to a higher, safer orbit over the following months. This mission highlights the increasing difficulty of maintaining operational satellites amid a rapidly expanding field of space debris. For most of the history of space exploration, satellites were considered expendable. Once they reached the end of their operational lives, whether due to running out of fuel or malfunctioning, they were typically left to drift or deorbit uncontrollably. This was less of a concern during the early years of spaceflight, when the number of objects in orbit was relatively low. Today, however, the situation has changed dramatically. Space surveillance systems now monitor tens of thousands of human-made objects in orbit, and the European Space Agency estimates that over 1.2 million pieces of debris larger than half an inch (one centimeter) are currently circling Earth. These fragments, though seemingly small, pose serious risks due to their high velocities and potential for catastrophic collisions. Capturing a drifting satellite is not simply a matter of physically reaching it. As a doctoral researcher specializing in satellite servicing explains, the greatest challenge lies in predicting and managing the movement of these objects. Unlike terrestrial vehicles, satellites in orbit are constantly in motion, influenced by gravitational forces and other orbital dynamics. Approaching a satellite requires precise calculations to avoid collisions, and even minor miscalculations could result in further debris creation. One method used to assist in capturing satellites involves specialized features known as “tow hooks.” Some newer satellites are designed with these hooks, allowing servicer spacecraft to easily attach and manipulate them. For instance, Northrop Grumman’s Mission Extension Vehicles have successfully docked with communication satellites to extend their operational lifespans by taking over propulsion functions. However, many older satellites lack such features, making them significantly more challenging to service. The Swift Observatory presents a particular challenge because it was not constructed with any standard fixtures that would facilitate easy capture. Engineers must therefore rely on alternative methods to secure the satellite. This includes identifying potential attachment points based on visual assessments and estimating the satellite’s shape, mass, and trajectory using available sensor data. Even with these efforts, the risk remains that a chosen surface, such as a solar panel or antenna, may not be robust enough to withstand the forces involved in the capture process. As LINK approaches the Swift Observatory, it faces additional complications. The satellite is likely tumbling unpredictably, making it difficult to determine its exact position and orientation. Servicers must account for these movements by using advanced imaging and ranging technologies to build accurate models of the satellite’s behavior. When the robotic arm makes initial contact, the resulting forces can push the servicer away, requiring careful adjustments to maintain stability and prevent further damage. Each step of the operation demands meticulous planning and real-time adaptability to ensure success.