10-Year Anniversary of the European Proximity Operations Simulator 2.0 - Looking Back at Test Campaigns, Rendezvous Research and Facility Improvements

Completed in 2009, the European Proximity Operations Simulator 2.0 (EPOS 2.0) succeeded EPOS 1.0 at the German Space Operations Center (GSOC). One of the many contributions the old EPOS 1.0 facility made to spaceflight rendezvous is the verification of the Jena-Optronik laser-based sensors used by the Automated Transfer Vehicle. While EPOS 2.0 builds upon its heritage, it is a completely new design aiming at considerably more complex rendezvous scenarios. During the last ten years, GSOC’s On-Orbit-Servicing and Autonomy group, who operates, maintains and evolves EPOS 2.0, has made numerous contributions to the field of uncooperative rendezvous, using EPOS as its primary tool. After general research in optical navigation in the early 2010s, the OOS group took a leading role in the DLR project On-Orbit-Servicing End-to-End Simulation in 2014. EPOS 2.0 served as the hardware in the loop simulator of the rendezvous phase and contributed substantially to the project’s remarkable success. Over the years, E2E has revealed demanding requirements, leading to numerous facility improvements and extensions. In addition to the OOS group’s research work, numerous and diverse open-loop test campaigns for industry and internal (DLR) customers have shaped the capabilities of EPOS 2.0 significantly

A robust navigation filter fusing delayed measurements from multiple sensors and its application to spacecraft rendezvous

A filter is an essential part of many control systems. For example guidance, navigation and control systems for spacecraft rendezvous require a robust navigation filter that generates estimates of the state in a smooth and stable way. This is important for a safe spacecraft navigation within rendezvous missions. Delayed, asynchronous measurements from possibly different sensors require a new filter technique which can handle these different challenges. A new method is developed which is based on an Extended Kalman Filter with several adaptations in the prediction and correction step. Two key aspects are extrapolation of delayed measurements and sensor fusion in the filter correction. The new filter technique is applied on different close-range rendezvous examples and tested at the hardware-in-the-loop facility EPOS 2.0 (European Proximity Operations Simulator) with two different rendezvous sensors. Even with realistic delays by using an ARM-based on-board computer in the hardware-in-the-loop tests the filter is able to provide accurate, stable and smooth state estimates in all test scenarios

Robotics and AI-Enabled On-Orbit Operations With Future Generation of Small Satellites

The low-cost and short-lead time of small satellites has led to their use in science-based missions, earth observation, and interplanetary missions. Today, they are also key instruments in orchestrating technological demonstrations for On-Orbit Operations (O 3 ) such as inspection and spacecraft servicing with planned roles in active debris removal and on-orbit assembly. This paper provides an overview of the robotics and autonomous systems (RASs) technologies that enable robotic O 3 on smallsat platforms. Major RAS topics such as sensing & perception, guidance, navigation & control (GN&C) microgravity mobility and mobile manipulation, and autonomy are discussed from the perspective of relevant past and planned missions

Marshall Space Flight Center Research and Technology Report 2018

Many of NASAs missions would not be possible if it were not for the investments made in research advancements and technology development efforts. The technologies developed at Marshall Space Flight Center contribute to NASAs strategic array of missions through technology development and accomplishments. The scientists, researchers, and technologists of Marshall Space Flight Center who are working these enabling technology efforts are facilitating NASAs ability to fulfill the ambitious goals of innovation, exploration, and discovery

Analysis of the space debris problem: tracking, control and removal

The amount of space debris currently orbiting the Earth poses a risk to all spacecraft, and is a particular concern for vehicles with humans on board suchas the International Space Station, space shuttles and other manned spacecraft. ESA estimates that there are currently more than 26000 objects in space, of which only 2800 have any function. However, despite technological evolutions and scientific advances, there is still no definitive method to solve the space debris problem by capturing end-of-life satellites still in orbit around the Earth. The activities that have been carried out so far and will be analysed in this project are divided into monitoring, mitigation and disposal. The intention of this work is to expose the importance of knowing and analysing our space past and then to move on to the understanding of why it is so important to eradicate space debris by studying some possible theoretical solutions proposed during the last decades that focus on reduction and eliminatio

Modeling and Parameter Estimation of Spacecraft Lateral Fuel Slosh

Predicting the effect of fuel slosh on spacecraft and launch vehicle attitude control systems has been a very important and challenging task and has been the subject of considerable research over the past years. Analytic determination of the slosh analog parameters has been met with mixed success and is made more difficult by the introduction of propellant management devices such as elastomeric diaphragms. The experimental set-up in this research incorporates a diaphragm in a simulated spacecraft fuel tank subjected to lateral slosh behavior. This research focuses on the parameter estimation of a SimMechanics model of the simulated spacecraft propellant tank with diaphragms using lateral fuel slosh experiment data. An experimental investigation was conducted to determine and measure the slosh forces response of free surface slosh and diaphragms in an eight inch diameter spherical tank. The lateral slosh testing consisted of the tank assembly partially filled with different liquids, for other tests, diaphragms were incorporated into the tank. The experiment results from different testing conditions were compared for estimation of unknown parameter characteristics that include the pendulum model stiffness constants and damping coefficients

Ion beam shepherd: analysis of the plasma bridge interaction

In the context of an exponential increase in the space debris population, which might yield to a substantial reduction of space activities in highly exploited orbits in a near future, new techniques for mitigating its growth are of key importance and are receiving an increasing attention in the international community. Among many proposals for active debris removal stands the Ion Beam Shepherd (IBS), a method which consists in a spacecraft rendez-vousing with the space debris object and relocating it to a di erent orbit with the use of electric propulsion. Such a shepherd spacecraft consequently requires two main thrusters, one directed at the target object, which transmits a force to it through the action of the ions of the plasma plume, and the other one, used to compensate the thrust generated by the rst, thus maintaining the satellite and the debris at a constant distance throughout the de-orbiting or re-orbiting mission. In this bachelor's thesis, the plasma interaction between the IBS and a target debris is studied through simulations. The software used for modelling the system and simulating its physics is SPIS (Spacecraft Plasma Interaction Software), an open source software developed by Onera and Artenum under the contract of the European Space Agency. Unfortunately, some unexpected technical issues with the software made it impossible to study, in detail, the primary goal of the di erential charging between the IBS and the debris when a plasma bridge is established between the two objects. However, the corresponding limitations in the use of the SPIS software (not known a priori) were identi ed and its knowledge will certainly help any future project whose goal is to study the spacecraft-debris interaction in the context of the IBS. Finally, some satisfactory results were obtained for the study of ions back ow towards the IBS satellite, which is relevant for the positioning of sensors and optical cameras on the surface of the spacecraft and also for the performance of its solar arrays.Ingeniería Aeroespacia

Advanced LIDAR-based techniques for autonomous navigation of spaceborne and airborne platforms

The main goal of this PhD thesis is the development and performance assessment of innovative techniques for the autonomous navigation of aerospace platforms by exploiting data acquired by electro-optical sensors. Specifically, the attention is focused on active LIDAR systems since they globally provide a higher degree of autonomy with respect to passive sensors. Two different areas of research are addressed, namely the autonomous relative navigation of multi-satellite systems and the autonomous navigation of Unmanned Aerial Vehicles. The global aim is to provide solutions able to improve estimation accuracy, computational load, and overall robustness and reliability with respect to the techniques available in the literature. In the space field, missions like on-orbit servicing and active debris removal require a chaser satellite to perform autonomous orbital maneuvers in close-proximity of an uncooperative space target. In this context, a complete pose determination architecture is here proposed, which relies exclusively on three-dimensional measurements (point clouds) provided by a LIDAR system as well as on the knowledge of the target geometry. Customized solutions are envisaged at each step of the pose determination process (acquisition, tracking, refinement) to ensure adequate accuracy level while simultaneously limiting the computational load with respect to other approaches available in the literature. Specific strategies are also foreseen to ensure process robustness by autonomously detecting algorithms' failures. Performance analysis is realized by means of a simulation environment which is conceived to realistically reproduce LIDAR operation, target geometry, and multi-satellite relative dynamics in close-proximity. An innovative method to design trajectories for target monitoring, which are reliable for on-orbit servicing and active debris removal applications since they satisfy both safety and observation requirements, is also presented. On the other hand, the problem of localization and mapping of Unmanned Aerial Vehicles is also tackled since it is of utmost importance to provide autonomous safe navigation capabilities in mission scenarios which foresee flights in complex environments, such as GPS denied or challenging. Specifically, original solutions are proposed for the localization and mapping steps based on the integration of LIDAR and inertial data. Also in this case, particular attention is focused on computational load and robustness issues. Algorithms' performance is evaluated through off-line simulations carried out on the basis of experimental data gathered by means of a purposely conceived setup within an indoor test scenario

2020 NASA Technology Taxonomy

This document is an update (new photos used) of the PDF version of the 2020 NASA Technology Taxonomy that will be available to download on the OCT Public Website. The updated 2020 NASA Technology Taxonomy, or "technology dictionary", uses a technology discipline based approach that realigns like-technologies independent of their application within the NASA mission portfolio. This tool is meant to serve as a common technology discipline-based communication tool across the agency and with its partners in other government agencies, academia, industry, and across the world

Marshall Space Flight Center Research and Technology Report 2015

The investments in technology development we made in 2015 not only support the Agency's current missions, but they will also enable new missions. Some of these projects will allow us to develop an in-space architecture for human space exploration; Marshall employees are developing and testing cutting-edge propulsion solutions that will propel humans in-space and land them on Mars. Others are working on technologies that could support a deep space habitat, which will be critical to enable humans to live and work in deep space and on other worlds. Still others are maturing technologies that will help new scientific instruments study the outer edge of the universe-instruments that will provide valuable information as we seek to explore the outer planets and search for life