Editorial

Diversity matters, both at the firm and at the macro-economic level. This is the driving mission of JEOD. While the importance of diversity is already quite well recognized in other disciplines as a major source of wellbeing and quality of life, an open discussion on diversity in economics (meaning both diversity of enterprise types and diversity in the possible combinations of public and private sector roles in different economic systems) has long been taboo. JEOD wants to remove this anomaly

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

Unveiling the inner morphology and gas kinematics of NGC 5135 with ALMA

Active galactic nuclei are thought to play a major role in the formation and evolution of galaxies, providing mechanisms for feedback from the supermassive black hole (SMBH) to its hosting galaxy and the intergalactic medium. In co-evolutionary scenarios, the SMBH properties are strictly connected to those of the host galaxy, in either high redshift quasars and in local Seyfert nuclei. Local Seyfert galaxies hosting both SMBHs and star forming regions, can be considered as the nearest counterparts of high redshift sub-mm heavily dust obscured star forming galaxies, where a significant fraction of the optical and UV photons are absorbed by dust are re-emitted in the IR and sub-mm bands. In the absence of major merging events and companions, the mechanisms that link the star formation (SF) and the accretion onto the black hole (BH) lie in the inner galactic regions (within ~1 kpc from the BH) and are responsible for the feeding of the BH and the quenching of the SF through feedback mechanisms from the BH itself. On the one hand, high resolution observations in the sub-mm band suggest that feeding might happen through the formation of bars at the inner end of the spiral galactic arms. On the other hand, outflows from the SMBHs have been observed and seem to be responsible for halting the gas infall and the SF in the inner galactic regions. Fuelling and outflows seem to constitute a self-regulating combination of processes on the small scales that determine the galaxy morphology and dynamics. How the small scales dynamics influences the overall galaxy morphology, what is the timescale on which different processes happen, and if the different evolutionary stages justify the different observed morphologies, are still open questions. This thesis project develops within the above astrophysical context, with the main goal of studying the morphology, the kinematics and the physical processes at play in the inner regions of the nearby Seyfert 2 galaxy NGC 5135 with ALMA

Virtual and rapid prototyping of an underactuated space end effector

A fast and reliable verification of an initial concept is an important need in the field of mechatronics. Usually, the steps for a successful design require multiple iterations involving a sequence of design phases-the initial one and several improvements-and the tests of the resulting prototypes, in a trial and error scheme. Now a day’s software and hardware tools allow for a faster approach, in which the iterations between design and prototyping are by far reduced, even to just one in favorable situation. This work presents the design, manufacturing and testing of a robotic end effector for space applications, realized through virtual prototyping, followed by rapid prototyping realization. The first process allows realizing a mathematical model of the robotic system that, once all the simulations confirm the effectiveness of the design, can be directly used for the rapid prototyping by means of 3D printing. The workflow and the results of the process are described in detail in this paper, showing the qualitative and quantitative evaluation of the performance of both the virtual end effector and the actual physical robotic hand

AiiDA: Automated Interactive Infrastructure and Database for Computational Science

Computational science has seen in the last decades a spectacular rise in the scope, breadth, and depth of its efforts. Notwithstanding this prevalence and impact, it is often still performed using the renaissance model of individual artisans gathered in a workshop, under the guidance of an established practitioner. Great benefits could follow instead from adopting concepts and tools coming from computer science to manage, preserve, and share these computational efforts. We illustrate here our paradigm sustaining such vision, based around the four pillars of Automation, Data, Environment, and Sharing. We then discuss its implementation in the open-source AiiDA platform (http://www.aiida.net), that has been tuned first to the demands of computational materials science. AiiDA's design is based on directed acyclic graphs to track the provenance of data and calculations, and ensure preservation and searchability. Remote computational resources are managed transparently, and automation is coupled with data storage to ensure reproducibility. Last, complex sequences of calculations can be encoded into scientific workflows. We believe that AiiDA's design and its sharing capabilities will encourage the creation of social ecosystems to disseminate codes, data, and scientific workflows.Comment: 30 pages, 7 figure

GNSS relative navigation for operations in cislunar space

This paper investigates the performance of the forthcoming lunar navigation satellite systems for estimating not only the position of an onboard receiver in a lunar inertial reference frame, but also, and with a consistent accuracy, the relative position between two or more spacecraft in proximity. This could be the case of two spacecraft performing a rendezvous, of a lander released by an orbiter or the case of the permanent relative navigation service for a formation of satellites around the Moon. A cascade Kalman filter is implemented and the performance in terms of error statistics are shown for different mission profiles

Establishing a timeline for the high-mass star formation process

In this Thesis we aim to answer a long-standing astrophysical problem, quantifying the timescales of the evolutionary phases characterising the high-mass star formation process. Understanding the details of the formation of massive stars (i.e. M>8-10 Msun) is not trivial, since these objects are rare and at a relatively large distance. They also form and evolve very quickly and almost their entire formation takes place deeply embedded in their parental clumps. During the evolution, the chemical composition of massive clump can be heavily affected by the changes in density and temperature induced by the presence of massive young stellar objects. Chemical tracers that show a relation between their observed abundances and the different phases of the star formation process are commonly called chemical clocks. In this Thesis, through the comparison of observations of a large sample of massive clumps in different evolutionary stages, and accurate time-dependent chemical models, we estimate the timescales of the different phases over the entire star formation process. In addition, we provide relevant information on the reliability of crucial chemical clocks, both for the early and the late stages, confirming that chemistry is a powerful tool to establish a timeline for the high-mass star formation process