Spacecraft Pose Estimation

In recent years, the number of satellites launched into orbit has increased rapidly, aided by lower launch costs and minimal entry barriers, making space more accessible than ever before. Each space mission has a unique set of goals that influences the satellite’s size, functions and intended lifetime. In most mission scenarios, the satellites launched into orbit will last for the entire mission life-cycle and at the end of life, they are either moved to the graveyard orbit or left to re-enter the Earth’s atmosphere. However, a few space missions may encounter anomalies or malfunctions before their full life span. These malfunctioned satellites may become non-cooperative and threaten existing space infrastructure. To tackle such scenarios, the demand for orbital missions targeting On-Orbit Servicing (OOS) and Active Debris Removal (ADR) has steadily increased, as OOS and ADR are considered key spaceflight capabilities for the next decade. OOS is defined as the process of inspection, maintenance and repair of a system as an in-space operation. Commercial OOS missions aim to perform various functions, including providing life extension, maintaining the spacecraft, rescuing and recovering satellites from deployment failures and assisting astronauts with extravehicular activities. ADR is the process of removing obsolete space objects (such as satellites, rocket bodies, or fragments of spacecraft) through an external disposal method, thus minimizing the build-up of unnecessary objects and lowering the probability of on-orbit collisions that can fuel a “collision cascade”. Several technology demonstration missions, including PROBA-3 by the European Space Agency (ESA), PRISMA by OHB Sweden and commercial missions such as MEV-1 by Northrop Grumman, had been carried out successfully in recent years. Future missions such as Clearspace-1 by ESA and Clearspace are already in preparation to demonstrate ADR in 2026.