The global carbon budget and the Paris agreement

Purpose–The main purpose of this paper is to introduce the concept of global carbon budget (GCB) as akey concept that should be introduced as a reference when countries formulate their mitigation contributionsin the context of the Paris Agreement and in all the monitoring, reporting and verification processes that mustbe implemented according to the decisions of the Paris Summit.Design/methodology/approach–A method based on carbon budget accounting is used to analyze theintended nationally determined contributions (INDCs) submitted by the 15 countries that currently head theranking of global emissions. Moreover, these INDCs are analyzed and compared with each other. Sometimes,inadequate methodologies and a diverse level of ambition in the formulated targets are observed.Findings–It is found that the INDCs of those 15 countries alone imply the release into the atmosphere of 84per cent of the GCB for the period 2011-2030, and 40 per cent of the GCB available until the end of the century.Originality/value–This is thefirst time the INDCs of the top 15 emitters are analyzed. It is also thefirstanalysis made using the GCB approach. This paper suggests methodological changes in the way that thefuture NDCs might be formulated.Peer ReviewedPostprint (published version

A Review and Gap Analysis of Exploiting Aerodynamic Forces as a Means to Control Satellite Formation Flight

Using several small, unconnected satellites flying in formation rather than a single monolithic satellite has many advantages. As an example, separate optical systems can be combined to function as a single larger (synthetic) aperture. When the aperture is synthesized, the independent optical systems are phased to form a common image field with its resolution determined by the maximum dimension of the array. Hence, a formation is capable of much finer resolution than it could be accomplished by any single element. In order for the formation to maintain its intended design despite present perturbations (formation keeping), to perform rendezvous maneuvers or to change the formation design (reconfiguration) control forces need to be generated. To this day, using chemical and/or electric thrusters are the methods of choice. However, their utilization has detrimental effects on small satellites’ limited mass, volume and power budgets. In the mid-eighties, Caroline Lee Leonard published her pioneering work [1] proving the potential of using differential drag as a means of propellant-less source of control for satellite formation flight. This method consists of varying the aerodynamic drag experienced by different spacecraft, thus generating differential accelerations between them. Since its control authority is limited to the in-plane motion, Horsley [2] proposed to use differential lift as a means to control the out-of-plane motion. Due to its promising benefits, a variety of studies from researches around the world have enhanced Leonard’s work over past decades which results in a multitude of available literature. Besides giving an introduction into the method the major contributions of this paper is twofold: first, an extensive literature review of the major contributions which led to the current state-of-the-art of different lift and drag based satellite formation control is presented. Second, based on these insights key knowledge gaps that need to be addressed in order to enhance the current state-of-the-art are revealed and discussed. In closer detail, the interdependence between the feasibility domain and advanced satellite surface materials as well as the necessity of robust control methods able to cope with the occurring uncertainties is assessed.Peer ReviewedPostprint (published version

Selective Detection of Aeromonas Spp. By a Fluorescent Probe Based on the Siderophore Amonabactin

[Abstract] Amonabactins, the siderophores produced by some pathogenic bacteria belonging to Aeromonas genus, can be used for the preparation of conjugates to be imported into the cell using their specific transport machinery. Herein, we report the design and synthesis of a new amonabactin-based fluorescent probe by conjugation of the appropriate amonabactin analogue to sulforhodamine B (AMB-SRB) using a thiol-maleimide click reaction. Growth promotion assays and fluorescence microscopy studies demonstrated that the AMB-SRB fluorescent probe was able to label the fish pathogenic bacterium A. salmonicida subsp. salmonicida through its outer membrane transport (OMT) protein FstC. The labelling of other Aeromonas species, such as the human pathogen A. hydrophila, indicates that this probe can be a very useful molecular tool for studying the amonabactin-dependent iron uptake mechanism. Furthermore, the selective labelling of A. salmonicida and other Aeromonas species in presence of other fish pathogenic bacteria, suggest the potential application of this probe for detection of Aeromonas in water and other fish farming samples through fluorescence assays.This work was supported by grants RTI2018-093634-B-C21/C22 from the State Agency for Research (AEI) of Spain, cofunded by the FEDER Programme from the European Union (MCIN/AEI/10.13039/501100011033/FEDER). M.B. was supported by grant PID2019-103891RJ-100 from MCIN/AEI (Spain). Work in University of Santiago de Compostela and University of A Coruña was also supported by grants GRC2018/018 and GRC2018/039, respectively, from Xunta de Galicia and BLUEBIOLAB (0474_BLUEBIOLAB_1_E), Programme INTERREG V A of Spain-Portugal (POCTEP). D.R-V. thanks Xunta de Galicia (Spain) for a predoctoral fellowship. J.C.-S. thanks to the FPU National Program (FPU16/02060) of the Spanish Ministry of Science, Innovation and Universities for a predoctoral fellowshipXunta de Galicia; GRC2018/018Xunta de Galicia; GRC2018/03

On the exploitation of differential aerodynamic lift and drag as a means to control satellite formation flight

For a satellite formation to maintain its intended design despite present perturbations (formation keeping), to change the formation design (reconfiguration) or to perform a rendezvous maneuver, control forces need to be generated. To do so, chemical and/or electric thrusters are currently the methods of choice. However, their utilization has detrimental effects on small satellites’ limited mass, volume and power budgets. Since the mid-80s, the potential of using differential drag as a means of propellant-less source of control for satellite formation flight is actively researched. This method consists of varying the aerodynamic drag experienced by different spacecraft, thus generating differential accelerations between them. Its main disadvantage, that its controllability is mainly limited to the in-plain relative motion, can be overcome using differential lift as a means to control the out-of-plane motion. Due to its promising benefits, a variety of studies from researchers around the world have enhanced the state-of-the-art over the past decades which results in a multitude of available literature. In this paper, an extensive literature review of the efforts which led to the current state-of-the-art of different lift and drag-based satellite formation control is presented. Based on the insights gained during the review process, key knowledge gaps that need to be addressed in the field of differential lift to enhance the current state-of-the-art are revealed and discussed. In closer detail, the interdependence between the feasibility domain/the maneuver time and increased differential lift forces achieved using advanced satellite surface materials promoting quasi-specular or specular reflection, as currently being developed in the course of the DISCOVERER project, is discussed.Peer ReviewedPostprint (author's final draft

Inductive Plasma Thruster (IPT) for an Atmosphere-Breathing Electric Propulsion System: design and set in operation

Challenging space missions include those at very low orbits, where the atmosphere is source of significant drag on a satellite. Therefore, an efficient dragcompensation propulsion system is required to extend the mission lifetime. One solution is Atmosphere-Breathing Electric Propulsion (ABEP), a system that collects atmospheric particles and directly uses them as propellant for an electric thruster, therefore minimizing the requirement of limited propellant availability. The system is theoretically applicable to any celestial body with atmosphere. This would enable new mission types due to the new altitude ranges available for continuous orbiting. Challenging is also the presence of reactive chemical species, such as atomic oxygen in Earth orbit, erosion source of (not only) the propulsion system components, i.e. acceleration grids, electrodes and discharge channels of conventional EP systems such as RIT and HET. IRS is developing within the DISCOVERER project an intake and a thruster for an ABEP system. This paper, deals with the design of novel contact-less RF thruster, the inductive plasma thruster (IPT) based on a novel antenna design.The DISCOVERER project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No.737183Postprint (published version

Advances on the Inductive Plasma Thruster Design for an Atmosphere-Breathing EP System

Challenging space mission scenarios include those in very low Earth orbits, where the atmosphere creates significant drag to the S/C and forces their orbit to an early decay. For drag compensation, propulsion systems are needed, requiring propellant to be carried on-board. An atmosphere-breathing electric propulsion system (ABEP) ingests the residual atmosphere through an intake and uses it as propellant for an electric thruster. Theoretically applicable to any planet with atmosphere, the system might allow drag compensation for an unlimited time without carrying propellant. A new range of altitudes for continuous operation would become accessible, enabling new scientific missions while reducing the required effort for the launcher by achieving these low orbits. Preliminary studies have shown that the collectible propellant flow for an ion thruster in low Earth orbit (LEO) might not be enough, and that electrode erosion due to aggressive gases, such as atomic oxygen, will limit the thruster’s lifetime. In this paper we present the advances on the design of an inductive plasma thruster (IPT) for the ABEP. The IPT is based on a small-scale inductively heated plasma generator IPG6-S. IPG have the advantage of being electrodeless, and have already shown high electric-tothermal coupling efficiencies using O2 and CO2 as propellant. IPG6-S requires a scaling of the discharge channel to meet with power requirement and expected collected mass flows, as well as optimisation of the accelerating stage, to provide the required thrust to the spacecraft. Tests have been performed to verify some of the parameters and are as well presented within this paper.Peer ReviewedPostprint (published version

The benefits of very low earth orbit for earth observation missions

Very low Earth orbits (VLEO), typically classified as orbits below approximately 450 km in altitude, have the potential to provide significant benefits to spacecraft over those that operate in higher altitude orbits. This paper provides a comprehensive review and analysis of these benefits to spacecraft operations in VLEO, with para-metric investigation of those which apply specifically to Earth observation missions. The most significant benefit for optical imaging systems is that a reduction in orbital altitude improves spatial resolution for a similar payload specification. Alternatively mass and volume savings can be made whilst maintaining a given performance. Similarly, for radar and lidar systems, the signal-to-noise ratio can be improved. Additional benefits include improved geospatial position accuracy, improvements in communications link-budgets, and greater launch vehicle insertion capability. The collision risk with orbital debris and radiation environment can be shown to be improved in lower altitude orbits, whilst compliance with IADC guidelines for spacecraft post-mission lifetime and deorbit is also assisted. Finally, VLEO offers opportunities to exploit novel atmosphere-breathing electric propulsion systems and aerodynamic attitude and orbit control methods. However, key challenges associated with our understanding of the lower thermosphere, aerodynamic drag, the requirement to provide a meaningful orbital lifetime whilst minimising spacecraft mass and complexity, and atomic oxygen erosion still require further research. Given the scope for significant commercial, societal, and environmental impact which can be realised with higher performing Earth observation platforms, renewed research efforts to address the challenges associated with VLEO operations are requiredThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 737183Peer ReviewedPostprint (author's final draft

Distributing the global carbon budget with climate justice criteria

In this paper, a model for the distribution of the Global Carbon Budget between the countries of the world is presented. The model is based on the criteria of equity while also taking into account the different historical responsibilities. The Global Carbon Budget corresponds to the quantity of carbon dioxide emissions that can still be released into the atmosphere while maintaining the increase in the average earth surface temperature below 2 °C, and it is therefore compatible with the long-term objective defined in the Paris Agreement. The results of applying the model are shown both for the 15 emitters that currently top the ranking for world emissions as well as for the other countries, which are grouped together in three main groups: Other African, Other Latin American and Caribbean, and the Rest of the World. Mitigation curves compatible with the carbon budget allocated to the different countries are presented. When comparing each emitter’s historical emissions for the period 1971–2010 with the proposed distribution for the period 2011–2050 obtained using the model, it can be seen that developed countries must face the future with a greatly reduced carbon budget, whereas developing countries can make use of a carbon budget that is higher than their cumulative historical emissions. Finally, there is a discussion about how a model with these characteristics could be useful when implementing the Paris Agreement.Peer ReviewedPostprint (author's final draft

Mission analysis of nanosatellite constellations with OpenSatKit

CubeSat reliability is still considered an obstacle due to the sizeable fail rates generally attributed to the dead-on-arrival cases and early subsystem malfunctions. Thus, as CubeSats' primary purpose moves from technological demonstrations and university projects to missions where a significant risk of failure is not acceptable, an inexpensive method to emulate low Earth orbit constellations is being researched. The results presented have been developed in the framework of the PLATHON research project, which intends to develop a hardware-in-the-loop emulation platform for nanosatellite constellations with optical inter-satellite communication and ground-to-satellite links. Consequently, a crucial aspect of this project is to have a sufficiently precise orbital propagator with real-time manoeuvring control and graphical representation. NASA's OpenSatKit, a multi-faceted open-source platform with an inbuilt propagator known as 42, has been chosen to analyse the programme's feasibility in order to create a constellation testing bench. As an initial development of a software-in-the-loop application, the pre- processing of files has been automated; enhanced Attitude Determination and Control System manoeuvres have been added and configured through bidirectional socket interfaces, and the results format has been modified to be easily post-processed with MATLAB and Simulin

A Double-Track Pathway to Fast Strategy in Humans and Its Personality Correlates

The fast-slow paradigm of life history (LH) focuses on how individuals grow, mate, and reproduce at different paces. This paradigm can contribute substantially to the field of personality and individual differences provided that it is more strictly based on evolutionary biology than it has been so far. Our study tested the existence of a fast-slow continuum underlying indicators of reproductive effort¿offspring output, age at first reproduction, number, and stability of sexual partners¿in 1,043 outpatients with healthy to severely disordered personalities. Two axes emerged reflecting a double-track pathway to fast strategy, based on restricted and unrestricted sociosexual strategies. When rotated, the fast-slow and sociosexuality axes turned out to be independent. Contrary to expectations, neither somatic effort¿investment in status, material resources, social capital, and maintenance/survival¿was aligned with reproductive effort, nor a clear tradeoff between current and future reproduction was evident. Finally, we examined the association of LH axes with seven high-order personality pathology traits: negative emotionality, impulsivity, antagonism, persistence-compulsivity, subordination, and psychoticism. Persistent and disinhibited subjects appeared as fast-restricted and fast-unrestricted strategists, respectively, whereas asocial subjects were slow strategists. Associations of LH traits with each other and with personality are far more complex than usually assumed in evolutionary psychology