Review of On-Orbit Servicing Considerations for Low-Earth Orbit Constellations

Abstract

The field of on-orbit servicing (OOS) has matured to a viable industry through the progression of many technological milestones over the last several decades. Starting from the first orbital rendezvous of Gemini 6 in 1965 to Northrop Grumman's Mission Extension Vehicle successful reposition of Intelsat 901 in 2020, the scientific and engineering achievements have enabled a promising new capability in space. This OOS capability enables higher flexibility, risk reduction, and new expanded system architectures. More recently, the space industry is rapidly deploying a high number of satellites in proliferated low-earth orbit (LEO) constellations at orders of magnitude not seen before. This paper will review enabling technologies, upcoming OOS programs, emerging proliferated constellations, and orbital environmental conditions that enable OOS for potential future clients in LEO. These environmental conditions consist of LEO orbit sensitivities, orbital maneuvers, J2 earth oblateness, and propulsion considerations.

Active 6 DoF Force/Torque Control Based on Dynamic Jacobian for Free-Floating Space Manipulator

“…Small, unmanned servicing satellites will be used to conduct in-orbit servicing and active debris removal missions (Luu and Hastings, 2021). Capture of the target object will be a major challenge of the proposed missions (Fehse, 2014).…”

Application of Impedance Control of the Free Floating Space Manipulator for Removal of Space Debris

“…The highest risk is posed by large defunct satellites occupying important, and populated orbits like the geostationary or low Earth orbit [24]. The capability to physically intercept such objects opens a possibility to lower the risk of their collision with other satellites [10]. The captured defunct spacecraft or upper stages of launchers can be then manoeuvred away from the orbit where they posed a danger, using the propulsion and orbit control capabilities of the robotized satellite [4].…”

Centralized/decentralized indirect robust adaptive control for spacecraft attitude and robotics

“…1 The concepts of on-orbit servicing (OOS), miniaturization, and reusability of space assets are leading a change of paradigm in the space sector, which demands a even higher level of system autonomy and capability to react and adapt to different working conditions. 2 A typical example of such new scenarios is the case of a large carrier spacecraft with the task to release in different target orbits several passenger satellites: 3,4 at each release, mass and moment of inertia of the carrier suddenly change, with the system required to react without losses in pointing accuracy. The concept of OOS, in which a servicer spacecraft performs different tasks to prolong the lifetime of several target satellites, such as tugging, refueling, station keeping or even mechanical maintenance, requires the attitude control to be robust to a varying inertia in order to keep the system stable in all the different maneuvers: the servicer can acts alone or connected with the target, is required to perform complex grasping maneuvers to achieve connection, and it needs to handle the satellite stack even during mass transfers like refueling activities.…”