Autonomous RPOD Technology Challenges for the Coming Decade

Rendezvous Proximity Operations and Docking (RPOD) technologies are important to a wide range of future space endeavors. This paper will review some of the recent and ongoing activities related to autonomous RPOD capabilities and summarize the current state of the art. Gaps are identified where future investments are necessary to successfully execute some of the missions likely to be conducted within the next ten years. A proposed RPOD technology roadmap that meets the broad needs of NASA's future missions will be outlined, and ongoing activities at OSFC in support of a future satellite servicing mission are presented. The case presented shows that an evolutionary, stair-step technology development program. including a robust campaign of coordinated ground tests and space-based system-level technology demonstration missions, will ultimately yield a multi-use main-stream autonomous RPOD capability suite with cross-cutting benefits across a wide range of future applications

Facility for validating technologies for the autonomous space rendezvous and docking to uncooperative targets

We present the latest advancements in the air-bearing facility installed at La Sapienza’s GN Lab in the School of Aerospace Engineering. This facility has been utilized in recent times to validate robust control laws for simultaneous attitude control and vibration active damping. The instrumentation and testbed have been restructured and enhanced to enable simulations of close proximity operations. Relative pose determination, accomplished through visual navigation as either an auxiliary or standalone system, is the first building block. Leveraging the acquired knowledge, optimal guidance and control algorithms can be tested for contactless operations (e.g. on-orbit inspection), as well as berthing and docking tasks

Development and Launch of the World\u27s First Orbital Propellant Tanker

This paper describes the development of Orbit Fab’s Tanker-001 Tenzing mission, the world’s first orbital propellant tanker. The development of a robust orbital propellant supply chain is critical to accelerating the growth of government and commercial space activities. The widespread availability of spacecraft refueling has the potential to provide a number of revolutionary benefits. High-value space assets could have their operational lives extended, as they would no longer be constrained by the amount of propellant stored onboard for maneuvering. On-orbit servicing missions would become more efficient, as servicing vehicles could be refueled and repeatedly used. A large orbital propellant supply would also enable new mission and business models based on operational flexibility and frequent maneuvering. These benefits would be particularly impactful on small satellites, where the ability to refuel could overcome the operational constraints of having smaller propellant tanks. This will greatly expand the market for small spacecraft as it increases their range of missions and capabilities. Launching no earlier than June 24, 2021, Tenzing is a 35 kg small satellite with an Astro Digital bus carrying a supply of storable propellant, high test peroxide (HTP). Tenzing’s propellant supply is being offered to customers for refueling and used to gather data on propellant storage. In addition to being the first propellant tanker, Tenzing is also an orbital laboratory including a variety of payloads intended to test key technologies for refueling. This includes the first flight of Orbit Fab’s Rapidly Attachable Fluid Transfer Interface (RAFTI), a stereo camera system, and a Halcyon HTP propulsion system designed and built by Benchmark Space Systems for orbital maneuvers. The latter two elements can be used to test rendezvous and flyby maneuvers, providing data to support the development of full rendezvous, proximity operations, and docking (RPOD) systems for future Orbit Fab missions

Pose and Shape Reconstruction of a Noncooperative Spacecraft Using Camera and Range Measurements

Recent interest in on-orbit proximity operations has pushed towards the development of autonomous GNC strategies. In this sense, optical navigation enables a wide variety of possibilities as it can provide information not only about the kinematic state but also about the shape of the observed object. Various mission architectures have been either tested in space or studied on Earth. The present study deals with on-orbit relative pose and shape estimation with the use of a monocular camera and a distance sensor. The goal is to develop a filter which estimates an observed satellite's relative position, velocity, attitude, and angular velocity, along with its shape, with the measurements obtained by a camera and a distance sensor mounted on board a chaser which is on a relative trajectory around the target. The filter's efficiency is proved with a simulation on a virtual target object. The results of the simulation, even though relevant to a simplified scenario, show that the estimation process is successful and can be considered a promising strategy for a correct and safe docking maneuver