Derivation of the Planck and Fine-Structure Constant from Assis’s Gravity Model

Presently, Planck’s constant is a fundamental constant that can not be derived from other onstants. Assis developed a model based on an extended Weber-type potential energy, that allows calculating gravitational-type forces from neutral oscillating electric dipoles. Here we show that the maximum possible point-mass in his model equals the Planck mass which allows us to derive Planck’s constant and the fine-structure constant. We match the exact order of magnitude only requiring a pre-factor that is present in all Weber-type theories and has to be determined empirically. This classical model allows to link electromagnetic, gravitational and quantum properties with one approach

ASCenSIon innovative training network: mid-term overview and lessons learned

The field of access to space is wide and complex, and it involves several disciplines and areas of expertise such as propulsion physics, software development, experimental studies, numerical simulations, thermodynamics, missionisation, etc. A gap in the training of young European researchers at doctoral level has been identified in this field, as no high-level education programme exists with the ability to range across such a large range of research topics. With the aim to fill this gap, 24 European entities from academia, industry and research centers have partnered in the framework of "ASCenSIon", an Innovative Training Network funded by the European Commission within the Horizon 2020 Marie Skłodowska Curie Action. The objective of the project is to contribute to the establishment of a both ecologically and economically sustainable space access for Europe, therefore advancing its State of the Art. This is achieved by training 15 Early Stage Researchers of different background, nationality, gender and age, to become experts in their fields and to have a deep understanding of the access to space domain as a whole. Within ASCenSIon, the Early Stage Researchers, who are enrolled in a PhD programme, acquire both technical and transferable skills thanks to an inclusive and diverse training programme held at local and project level. Unlike more ordinary PhDs, the training offered by ASCenSIon does not only focus on narrow scopes of research fields, one domain (e.g. industry or academia) and one country. It features instead an interdisciplinary, intersectoral and multicultural approach. The offer includes training events in different forms, such as workshops, lectures, experimental weeks and summer schools, which are complemented by the participation in conferences and similar events. Given that the project started in January 2020 and will end in December 2023, this paper provides a midterm overview of the project and the lessons learned so far, with a particular focus on the remote vs in-person training experience forced by the Covid-19 pandemic outbreak

Trade-off between concurrent engineering software tools for utilisation in space education and beyond

Concurrent engineering is an approach to the development of complex systems that is char- acterised by direct communication between the disciplines involved. Instead of processing the individual disciplines one after the other, as in sequential design, or processing via a single contact person, as in centralised design, all systems work simultaneously. Learning this inter- action and understanding what information needs to be communicated between disciplines are among the central learning objectives of the course "Spacecraft Design" at Technische Uni- versität Dresden, Institute of Aerospace Engineering. In this course, the students represent different disciplines and work out a mission study that is commissioned by the lecturers. The lecturers thus participate in the development process in the role of customers. Key to the concurrent engineering approach is that each discipline has access to the most current design data at all times. This can be done via a dedicated software solution. Both commercial and open source software tools are available. Within the frame of the above-men- tioned course, several tools have been tested. The covered software solutions comprise ESA Open Concurrent Design Tool (OCDT), RHEA Concurrent Design Platform (CDP), Valispace and IBM Rhapsody. This contribution presents the experience that we gathered with these concurrent engineering software tools. First, the tools are described and their commonalities and distinctions are high- lighted. Subsequently, a detailed trade-off between the tools is being presented. This trade-off will particularly focus on the utilisation of these tools within the scope of course work at univer- sities, as this entails special requirements and boundary conditions, such as very limited time for introducing the software, highly heterogeneous user group, limited utilisation of the software in terms of depth and functionality, to only name a few. Within this contribution, we will also explore alternative approaches, such as using no software at all. The aim of this contribution is to offer other teachers and students some guideline for selecting a concurrent engineering software solution and implementing it in course work, in a way that using the tool itself does not become the central learning challenge of the course. The results might be of interest beyond university courses, as some requirements, like short times to get familiar with the software or certain interface requirements, also apply to other environments in research and development

Ultrafast transfer of low-mass payloads to Mars and beyond using aerographite solar sails

With interstellar mission concepts now being under study by various space agencies and institutions, a feasible and worthy interstellar precursor mission concept will be key to the success of the long shot. Here we investigate interstellar-bound trajectories of solar sails made of the ultra-light material aerographite, known for its low density (0.18 kg m$^{-3}$) and high absorptivity ($\mathcal{A}{\sim}1$), enabling remarkable solar irradiation-based acceleration. Payloads of up to 1 kg can swiftly traverse the solar system and the regions beyond. Our simulations consider various launch scenarios from a polar orbit around the Earth with direct outbound trajectories and Sun diver launches with subsequent outward acceleration. Utilizing the poliastro Python library, we calculate positions, velocities, and accelerations for a 1 kg spacecraft (including 720 g aerographite mass) with 10$^4$ m$^2$ of cross-sectional area, corresponding to a 56 m radius. A direct outward Mars transfer yields 65 km s$^{-1}$ in 26 d. The inward Mars transfer, with a sail deployment at a minimum distance of 0.6 AU, achieves 118 km s$^{-1}$ in 126 d. Transfer times and velocities vary due to the Earth-Mars constellation and initial injection trajectory. The direct interstellar trajectory peaks at 109 km s$^{-1}$, reaching interstellar space in 5.3 yr defined by the heliopause at 120 AU. Alternatively, the initial Sun dive to 0.6 AU provides 148 km s$^{-1}$ of escape velocity, reaching the heliopause in 4.2 yr. Values differ based on the minimum distance to the Sun. Presented concepts enable swift Mars flybys and interstellar space exploration. For delivery missions of sub-kg payloads, the deceleration remains a challenge.Comment: submitted to Acta Astronautica, Special Issue for the 8th Interstellar Symposium 2023, 8 pages, 10 Figures (5 col, 5 b/w), 1 Tabl

Particles with Negative Mass: Production, Properties and Applications for Nuclear Fusion and Self-Acceleration

Some experiments have indicated the possible existence of par ticles with a negative inertial mass. It is shown under which condit ions Weber’s electrodynamics gives rise to this effect. Some specific experiments related to this aspect of Weber’s law are described. Two particles equ ally electrified with charges of the same sign would then move toward one an other if they had negative effective inertial masses. A new concept for nuclear fusion is presented based on the possibility of creating a negative effective inertial mass for ions. It is then considered some properties of the inertial dipole, that is, a system composed by a pair of particles in which one particle has a positive effective inertial mass while the other particle has a negative effective inertial mass. The possible utilization of the inertialdipole as a propulsion system is briefly discussed

Avionics System and Attitude Algorithms for a Deorbit Device Based on an Electrodynamic Tether

The main goal of the Electrodynamic Tether technology for PAssive Consumable-less deorbit Kit (E.T.PACK) project is to develop a deorbit device based on an electrodynamic tether with TRL 4 by 2022. In September 2022, its continuation, i.e. the E.T.PACK-F project, will carry on with the activities of E.T.PACK to prepare a flight model with TRL 8 that will be tested in an in-orbit demonstration mission in 2025. This work (i) describes the attitude determination and control strategy of the mission, which is used as a means of explaining its different phases and the dynamics of each one of them, (ii) provides a description of the avionics elements of the whole system, (iii) describes some of the tests performed until this moment, and (iv) summarizes the current status and the future work

Environmental life cycle assessment of reusable launch vehicle fleets : large climate impact driven by rocket exhaust emissions

After the success of the reusable Falcon 9 rocket, space actors are pursuing competitive space access by developing Reusable Launch Vehicles (RLVs). While this initiative may enhance recycling rates, it may also trigger the Jevons’ paradox as it amplifies the overall environmental footprint due to increased launch frequencies. It is therefore essential to quantify RLVs’ impacts and identify key design drivers to enable efficient design choices while mitigating undesirable environmental effects. Consequently, this article uses a space specific Life Cycle assessment (LCA) approach to evaluate the environmental footprint, in terms of climate impact, water depletion and land use, of different RLV fleets designed to serve a forecasted European space market. The results show that the LH2 fleet options have 2-8 times lower carbon footprint when compared to the LCH4 fleet as a result of lower propellant consumption and lack of black carbon emissions, suggesting that the environmental burdens are mostly driven by propellant choice. Moreover, the analysis reveals a potential underestimation of climate impacts in previous LCA’s by 2–3 orders of magnitude due to the absence of high altitude characterisation of rocket exhaust emissions and demised aluminium oxides. This increased forcing could lead to fleet choices surpassing the Earth’s carrying capacity given by its planetary boundaries. The methodology and results within this study can support further integration of launch and reentry emissions within LCA by refining modelling techniques, improving impact characterisation and quantifying uncertainties. These advancements can ultimately enable robust eco-design strategies for launch vehicles

Evaluation of 3D printed buckyball-shaped cathodes of titanium and stainless-steel for IEC fusion system

An inertial electrostatic confinement (IEC) fusion device accelerates ions, such as deuterium (D) or tritium (T), to produce nuclear fusion and generate neutrons. The IEC's straightforward configuration consists of a concentric spherical transparent cathode at a negative bias surrounded by a grounded spherical anode. The effects of cathode properties on the neutron production rate (NPR) remain, to date, inadequately studied. This study aims to determine the impact of the cathode material on the NPR by investigating fusion reactions on the cathode surface. Two buckyball-shaped cathodes made of stainless steel (SS) and titanium (Ti), both of 5 cm diameter, fabricated by selective laser melting and 3D printing, are used for this investigation. A SS spherical chamber of 25 cm inner diameter is used as an anode in this experiment. A performance evaluation of surface fusion reaction in the IEC using SS and Ti grids is conducted by examining the NPR as a function of the applied voltage and grid currents at different gas pressures. So far, IEC with Ti and SS cathodes achieves NPRs of 2.32 and 1.41 × 10⁷n/s, respectively, at 5.6 kW (70 kV, 80 mA). The normalized NPRs (NPR/I-cathode) from IEC using SS and Ti cathodes are compared. The results demonstrate that fusion reaction occurs on the cathode surface, and fusion increases with the applied voltage. The measured NPR/I-cathode using the Ti cathode is higher than that of the SS cathode by factors of 1.36–1.64 across the 20–70 kV range. Moreover, fusion on the Ti cathode surface enhances the total NPR significantly compared to the SS cathode under the same conditions. The Ti's considerable ability to accumulate D ions and molecules compared with that of SS explains the difference of measured NPR results