NASA Automated Rendezvous and Capture Review. Executive summary

In support of the Cargo Transfer Vehicle (CTV) Definition Studies in FY-92, the Advanced Program Development division of the Office of Space Flight at NASA Headquarters conducted an evaluation and review of the United States capabilities and state-of-the-art in Automated Rendezvous and Capture (AR&C). This review was held in Williamsburg, Virginia on 19-21 Nov. 1991 and included over 120 attendees from U.S. government organizations, industries, and universities. One hundred abstracts were submitted to the organizing committee for consideration. Forty-two were selected for presentation. The review was structured to include five technical sessions. Forty-two papers addressed topics in the five categories below: (1) hardware systems and components; (2) software systems; (3) integrated systems; (4) operations; and (5) supporting infrastructure

Six degree of freedom manual controls study report

The feasibility of using degree of freedom manual controls in space in an on orbit environment was determined. Several six degree of freedom controls were tested in a laboratory environment, and replica controls were used to control robot arms. The selection of six degrees of freedom as a design goal was based on the fact that six degrees are sufficient to define the location and orientation of a rigid body in space

Tabletop Testbed for Attitude Determination and Control of Nanosatellites

To simulate the conditions of the space environment at ground, the Laboratory of Application and Innovation in Aerospace Science (LAICA) of the University of Brasília (UnB) is developing a dedicated testbed to reproducing nanosatellite attitude motion. The testbed is composed of an air-bearing table and a Helmholtz cage. The air-bearing table is a spacecraft simulator that can simulate frictionless conditions with three rotational degrees of freedom. Balancing the simulator is essential in order to make the gravitational torque negligible. The testbed is also equipped with a Helmholtz cage to recreate the Earth's magnetic field conditions that spacecrafts encounter in orbit. This paper presents the design and realization of this low-cost testbed. A simple and efficient automated balancing algorithm based on the least-squares method (LSM) is proposed and validated by experiments. The performance of the proposed simulator is evaluated and compared with previous works

Tabletop Testbed for Attitude Determination and Control of Nanosatellites

To simulate the conditions of the space environment at ground, the Laboratory of Application and Innovation in Aerospace Science (LAICA) of the University of Brasília (UnB) is developing a dedicated testbed to reproducing nanosatellite attitude motion. The testbed is composed of an air-bearing table and a Helmholtz cage. The air-bearing table is a spacecraft simulator that can simulate frictionless conditions with three rotational degrees of freedom. Balancing the simulator is essential in order to make the gravitational torque negligible. The testbed is also equipped with a Helmholtz cage to recreate the Earth's magnetic field conditions that spacecrafts encounter in orbit. This paper presents the design and realization of this low-cost testbed. A simple and efficient automated balancing algorithm based on the least-squares method (LSM) is proposed and validated by experiments. The performance of the proposed simulator is evaluated and compared with previous works. © 2018 American Society of Civil Engineers

Experimental Investigation of Spacecraft Rendezvous and Docking by Development of a 3 Degree of Freedom Satellite Simulator Testbed

This thesis developed a 3 degree of freedom air bearing satellite simulator testbed. The major components of this testbed are a 2-meter by 4-meter granite table, a pair of satellite simulators, and a passive infrared marker array. The goal of this implementation was to achieve soft docking between 2 satellite simulators while relying only on hardware and systems onboard the satellite simulator. The satellite simulators make use of compressed air stored onboard in tanks to supply the air bearing and gas thrusters. The air bearing system provides a thin cushion of air for the satellite simulator to float on, removing surface contact and friction between the satellite simulator and the granite table. This produces a 3 degree of freedom system which is effectively free of the effects of gravity. The infrared marker array is used to provide reference points similar to stars to enable an onboard positioning system using a single observer. The experimental results obtained here demonstrate the successful implementation of this testbed

Space Applications of Automation, Robotics and Machine Intelligence Systems (ARAMIS), phase 2. Volume 1: Telepresence technology base development

The field of telepresence is defined, and overviews of those capabilities that are now available, and those that will be required to support a NASA telepresence effort are provided. Investigation of NASA's plans and goals with regard to telepresence, extensive literature search for materials relating to relevant technologies, a description of these technologies and their state of the art, and projections for advances in these technologies over the next decade are included. Several space projects are examined in detail to determine what capabilities are required of a telepresence system in order to accomplish various tasks, such as servicing and assembly. The key operational and technological areas are identified, conclusions and recommendations are made for further research, and an example developmental program is presented, leading to an operational telepresence servicer

Conceptual Design of an Open-Source Hardware Simplified Floating Spacecraft Simulator

Prepared for: Universität der Bundeswehr HamburgThis thesis covers parts of the development of a new open-source hardware Floating Spacecraft Simulator for teaching and research purposes, named MyDAS, standing for Mini Dynamic Autonomous Spacecraft Simulator. A Floating Spacecraft Simulator (FSS) is an autonomous robotic vehicle which floats via air bearings on a smooth surface, is actuated by thrusters and controlled by an on-board computer. The use of FSS is advantageous as a cost-effective ground-test tool providing a level of fidelity between numerical simulations and orbital flight. Research has shown that physical of validation is important for advancing autonomous spacecraft maneuvers. Even though many FSS are in use worldwide in universities, research centers and industries, they are typically custom developed and expensive items. In this thesis for the first time, to the best knowledge of the author, a FSS is introduced which is designed to be as small and as inexpensive as possible, while maintaining a high level of spacecraft-emulation fidelity. By introducing MyDAS, the author aims at a broader utilization of spacecraft simulators for research and education at university level, and possibly also high-school level. In addition to being small and inexpensive, MyDAS shall use off-the-shelf and 3D-printed components to allow for customization and improvement. The preliminary design of MyDAS addresses three primary systems necessary to develop a miniature, simplified FSS. These systems include pneumatics, electronics, and structure. The fundamentals, the state of the art, as well as the conceptual design of this specific FSS are presented in this thesis.Universität der Bundeswehr Hamburg Fakultät für Maschinenbau Professur für Mechatronik Holstenhofweg 85 22043 Hamburg, GermanApproved for public release; distribution is unlimited

Video guidance, landing, and imaging systems

The adaptive potential of video guidance technology for earth orbital and interplanetary missions was explored. The application of video acquisition, pointing, tracking, and navigation technology was considered to three primary missions: planetary landing, earth resources satellite, and spacecraft rendezvous and docking. It was found that an imaging system can be mechanized to provide a spacecraft or satellite with a considerable amount of adaptability with respect to its environment. It also provides a level of autonomy essential to many future missions and enhances their data gathering ability. The feasibility of an autonomous video guidance system capable of observing a planetary surface during terminal descent and selecting the most acceptable landing site was successfully demonstrated in the laboratory. The techniques developed for acquisition, pointing, and tracking show promise for recognizing and tracking coastlines, rivers, and other constituents of interest. Routines were written and checked for rendezvous, docking, and station-keeping functions

Analysis and modeling of satellite flexible bodies in Simscape Multibody

Questa Tesi Magistrale fornisce un’analisi per trovare un metodo numericamente efficiente per modellare i corpi flessibili di un satellite. L’analisi numerica è condotta su MATLAB - Simulink confrontando due rappresentazioni matematiche dei corpi flessibili: il metodo a “parametri forfettari” e il metodo della “trave flessibile”, utilizzati per modellare un pannello solare e un braccio robotico a 3 GdL. Questo studio ha lo scopo di contribuire ad un progetto condotto presso l’Università di Padova in collaborazione con l’Agenzia Spaziale Europea (ESA): esso si concentra sullo sviluppo di tecnologie di Guidance Navigation Control (GNC) per missioni di In-Orbit Servicing (IOS) e Active Debris Removal (ADR), condotte da un veicolo spaziale, dotato di un braccio robotico in grado di afferrare detriti spaziali e agganciare altri satelliti; in particolare, l’attività di ricerca oggetto del contratto è un simulatore della dinamica di scenari per Close Proximity Operations (CPOs), denominato Functional Engineering Simulator (FES). Il pannello solare e il braccio robotico, montati sul satellite, devono essere studiati perché le loro deformazioni possono occasionalmente diventare abbastanza severe da influenzare sia le proprie prestazioni che quelle degli altri sistemi. Se ciò dovesse accadere, le vibrazioni verrebbero notevolmente amplificate, accelerando il tasso di usura meccanica, aumentando il consumo di energia e interferendo con i compiti che necessitano un’alta precisione. Gli obiettivi di questa tesi Magistrale sono: (1) creare un Simulatore adatto per studiare la risposta dinamica del pannello solare soggetto a perturbazioni esterne e gli effetti degli elementi flessibili del braccio robotico durante il suo movimento, (2) confrontare i due metodi dei corpi flessibili in termini di accuratezza dei risultati e tempi di simulazione, (3) trovare il modello matematico che possa rappresentare adeguatamente la teoria dei corpi flessibili, in modo da poter essere utilizzato per modellare un vero simulatore. Il pannello solare è stato modellato secondo due diversi scenari, i quali rappresentano due esempi di architetture di missioni spaziali che prevederanno operazioni con bracci robotici nel prossimo futuro. Il suo comportamento è stato studiato analizzando la risposta degli impulsi causati dalle perturbazioni esterne che agiscono sulla superficie del pannello solare. Invece, il braccio robotico è stato modellato per seguire un percorso rettilineo da un punto iniziale a un punto finale e il comportamento dei suoi elementi flessibili è stato studiato ad ogni istante del suo movimento. Per modellare un elemento del veicolo spaziale, il metodo della trave flessibile utilizza un blocco già esistente di Simscape Multibody. Per questo motivo, esso è stato considerato come metodo di riferimento per verificare l’affidabilità di quello a parametri forfettari, per il quale i risultati hanno dimostrato essere uno metodo valido per descrivere il comportamento dei corpi flessibili di un veicolo spaziale, soprattutto grazie ai suoi rapidi tempi di simulazione, i quali lo rendono adatto per modellare in un vero simulatore.This Master Thesis provides an analysis to find a numerically efficient method to model a satellite flexible bodies in the MATLAB - Simulink environment. The numerical analysis is conducted by comparing two mathematical representations of flexible bodies: the Lumped-parameter method and the Flexible-beam method, which are implemented by the Simulation Tool to model and simulate the dynamics of a solar panel and a 3-DOF robotic arm. This study is on purpose to contribute to a project conducted at the University of Padua in collaboration with the European Space Agency (ESA): it focuses on the development of the Guidance Navigation Control technologies (GNC) suitable to be applied to both In-Orbit Servicing (IOS) and Active Debris Removal (ADR) missions conducted by a chaser spacecraft equipped with a robotic arm that can grab space debris and lock onto other satellites; in particular, the research activity under contract is a simulator of the dynamics of Close Proximity Operations (CPOs) scenarios, called Functional Engineering Simulator (FES). The solar panel and robotic arm mounted on the spacecraft behave as flexible bodies and need to be studied because their deformations may occasionally become severe enough to affect the performance of their respective systems. If these effects occur, vibrations are significantly amplified, accelerating the rate of mechanical wear, increasing power consumption, and interfering with high-precision tasks. The goals of this Master Thesis are: (1) to create a reliable simulation tool to study the dynamic response of the solar panel subject to external perturbations and the effects of the flexible elements of the robotic arm during its motion, (2) to compare the two flexible body methods in terms of accuracy of results and execution time, (3) to find the mathematical model that can adequately represent the flexible body theory so that it can be used to model a real-time simulator. The solar panel is modeled according to two different scenarios, which represent two examples of space mission architectures requiring robotic operations in the near future. Its behavior is studied by analyzing the response to impulses caused by external perturbations acting on the solar panel surface. On the other hand, the robotic arm is modeled to follow a rectilinear path from a starting point to an end point and the behavior of its flexible elements is studied at each time-step of this motion. The flexible-beam method consists of using an existing Simscape Multibody block to model the spacecraft element. Hence, it has been considered as a benchmark in order to verify the reliability of the lumped-parameter method, for which the results demonstrated that it is a valid tool for describing the behavior of flexible bodies of a spacecraft, mainly due to its fast execution times, which make it suitable for modeling in a real-time simulator

In-flight main beam reconstruction for Planck-LFI

In-flight measurement of the antenna main beams of the Planck instruments is a crucial input to the data analysis pipeline. We study the main beam reconstruction achievable through external planets using a flight simulator to model their observation. We restrict our analysis to the 30 GHz LFI channel but the method can be easily extended to higher frequency channels. We show that it is possible to fit the antenna response from Jupiter and Saturn to obtain an accurate, robust, simple and fast reconstruction of the main beam properties under very general conditions, independently of the calibration accuracy. In addition, we find that a bivariate Gaussian approximation of the main beam shapes represents a significant improvement with respect to a symmetric representation. We also show that it is possible to combine the detection of the planet's transit and Planck's very accurate in-flight calibration to measure the planet's temperature at millimetric wavelengths with an accuracy at the % level. This work is based on Planck-LFI activities.Comment: 10 pages, submitted to A&