The Humboldt Code: On creating a hybrid digital scholarly edition of a 19th century globetrotter

Tobias Kraft and Stefan Dumont report on the hybrid digital scholarly edition of Alexander von Humboldt. The complementary approach of ‘edition humboldt’ combines the strengths of a reader-friendly book edition with those of a digital full-text and facsimile edition based on a carefully curated data infrastructure. In addition to the advantages of the book for the concentrated study of longer texts, the online edition offers the complementary technological and methodological framework to provide a scholarly reliable basis for research into Humboldt’s work and life-long research activities. Tobias Kraft und Stefan Dumont geben einen Werkstattbericht zur Hybridedition von Humboldts Reisedokumenten im Rahmen des deutschen Akademieprogramms. Der Ansatz der ‚edition humboldt‘ verbindet die Stärken einer lesefreundlichen Buchedition mit denen einer digitalen Volltext- und Faksimile-Edition auf der Grundlage einer sorgfältig entwickelten Dateninfrastruktur.Tobias Kraft and Stefan Dumont report on the hybrid digital scholarly edition of Alexander von Humboldt. The complementary approach of ‘edition humboldt’ combines the strengths of a reader-friendly book edition with those of a digital full-text and facsimile edition based on a carefully curated data infrastructure. In addition to the advantages of the book for the concentrated study of longer texts, the online edition offers the complementary technological and methodological framework to provide a scholarly reliable basis for research into Humboldt’s work and life-long research activities

Aerothermal characterization of the CALLISTO vehicle during descent

Aerothermal loads are a design driving factor during launcher development as the thermal loads directly in- fluence TPS design and trajectory. Recent developments in reusable launch vehicles (RLV) (e.g. SpaceX, Blue Origin) have added the dimension of refurbishment to the challenges the thermal design must con- sider. For disposable launchers the heat flux due to base heating during ascent needs to be considered for aft thermal protections system (TPS) and structural design. With the current European long term strategy[1] moving towards a reusable first stage - aerothermal loads may significantly change. The CAL- LISTO vehicle is a flight demonstrator for future reusable launcher stages and their technologies. The program involves three countries and their space organizations: CNES for France, DLR for Germany and JAXA for Japan. The first tests will be conducted in 2024 from CSG, Europe’s Spaceport. The challenge is to develop, all along the project, the skills of the partners. This know-how includes products and vehicle design, ground segment set up, and post-flight operations for vehicle recovery then reuse [2–5]. For the CALLISTO vehicle the highest heat fluxes are mainly due to heating from hot exhaust gases and heated air in proximity of the aft bay and on the exposed structures like legs and fins. The development of the plume extension is different for the considered re-entry, when compared to Falcon 9, or the studies presented in [6–8]. As shown by Dumont et al.[9] the plume remains relatively concentrated at the aft end of the vehi- cle due to high atmospheric pressure and only very low fractions of actual exhaust gas species enclosing the vehicle. In the current study we conducted computational fluid dynamics (CFD) studies in order to determine the aerothermal loads on the vehicle during descent through the landing approach corridor for both phase B and phase C aeroshapes. The database development for vehicle phase B and phase C are described in detail and analyzed for some of the most prominent interfaces. The final phase C database presented allows interpolation of interface heatfluxes for the entire flight domain (M, ρ) at varying angle of attack (between 180 deg and 160 deg). Further the sensitivity of the plume-vehicle interaction to angle of attack, chemistry, thrust vector deflection and engine throttling are investigated for a critical Mach number indicating further area of improvement for future databases

Aerothermal analysis of plume interaction with deployed landing legs of the CALLISTO vehicle

The current European long term strategy aims at moving towards reusable launch vehicles (RLV) for the first stages of launchers. In accordance with this strategy the German Aerospace Center (DLR) has entered into a collaboration with the Japan Aerospace Exploration Agency (JAXA) and the French Space Agency (CNES) for the development of RLV relevant technologies. A part of this collaboration is a vertical take off and vertical landing (VTVL) reusable subscale launcher first stage demonstrator - the Cooperative Action Leading to Launcher Innovation in Stage Toss back Operations (CALLISTO). The mission of the CALLISTO vehicle is to return to the launch pad using retro propulsion and an Approach and Landing System (ALS) with extendable landing legs. This development leads to additional aerothermal design questions compared to traditional launchers. In the case of CALLISTO the highest heat fluxes are caused by heating from hot exhaust gases of the aft bay section. This especially affects the unfolded ALS during the final phase of the landing approach. The arising heat fluxes, therefore, influence the structural design and the thermal protection system (TPS) of the ALS. In this study we conduct computational fluid dynamics (CFD) investigations using Reynolds averaged Navier Stokes (RANS) methods of the aerothermal loads on the ALS during the landing phase. We use the Spalart-Allmaras turbulence model and frozen chemistry for the simulations. We analyse the flow field as well as the surface distributions. We investigate the necessity of simulations including the plume for these analyses. We use analyses of the flow fields as well as the surface distributions to investigate the influence of angle of attack, angle of roll, atmospheric conditions, flight speed and thrust level

Travelling Humboldt—Data on the Move. The “edition humboldt digital” as data publication

The long-term Academy project Travelling Humboldt–Science on the Move publishes the American, Russian-Siberian and European Travel Journals of the Prussian naturalist and explorer Alexander von Humboldt (1769–1859). The journals are accompanied by thematically related letters from his world-spanning correspondence network as well as manuscripts from his vast legacy collection, many of which have not been published before. Up to now, we have delivered eight subsequent versions of this digital, documentary edition. The TEI/XML subset of the ehd has been developed by adopting established TEI subsets, e.g. the German Text Archive’s Base Format for Manuscripts, to ensure the highest possible degree of standardisation, re-usability, and interoperability of the data. The comprehensive transcription and encoding guidelines illustrate the specifications of the ehd’s TEI format. The publication strategy is ‘digital first’, and the text-critical documentary edition can be fully accessed open access under a Creative Commons license. Following version 8 of the ehd (published in May 2022), we now fulfil the promise to deliver Humboldt’s complex handwritten and hard-to-decipher texts as free-licensed TEI-XML data by making available (1) the annotated text transcriptions of more than 500 documents (ca. 2.800 pages), (2) the comprehensive Alexander von Humboldt Chronology with about 1.600 individual, dated statements from Humboldt’s almost 90-year lifespan, and (3) about 18.000 index entries. The presentation focuses on this digital data publication, and illustrates our approach between re-using existing data and best practices on the one hand, and giving back to the wider (TEI) community on the other hand

Applying Bayesian Inference to Estimate Uncertainties in the Aerodynamic Database of CALLISTO

The three national space centers DLR, CNES & JAXA have joined their efforts in the project CALLISTO to develop and mature key technologies for future operational Reusable Launch Vehicles (RLVs). The goal of this project is to develop, manufacture and test a reusable Vertical-Takeoff Vertical-Landing (VTVL) first stage demonstrator, which will be operated at the European Spaceport in French Guiana from late 2024. One important aspect in the development of RLVs, but also of aerospace vehicles in general, is the generation of an Aerodynamic Database (AEDB) which characterizes the aerodynamic flying qualities of the vehicle. These databases are commonly aggregated from Computational Fluid Dynamics (CFD) simulations and Wind Tunnel Tests (WTTs) via simple heuristic models. Whereas this classical approach is suitable for the estimation of nominal aerodynamic coefficients, the quantification of uncertainties in this pre-flight data with respect to the final flight behavior is still a difficult task that involves a lot of human expert knowledge and "gut feeling". Particularly for launch vehicles, these uncertainties are however essential to ensure robust guidance and control algorithms, as well as sufficient vehicle performance for a selected mission profile. For CALLISTO, in parallel to a classical approach, a new methodology has now been tested to estimate these uncertainties within the AEDB: To apply Bayesian Inference to predict a probability distribution over the aerodynamic coefficients, conditional on the available test and simulation results and on prior knowledge. This methodology has already been well-established in other data science domains, but for aerospace engineering only very few use-cases are known so far. With this new approach an objectively traceable modelling of the aerodynamic uncertainties should be possible. This paper presents the current development state of the Bayesian aerodynamic uncertainties model of CALLISTO. After problem definition and a short introduction to the underlying dataset, the paper mainly focuses on the used modelling techniques and the applicability of Bayesian methods to the aerodynamic characterization problem. Selected results are shown for Bayesian models and compared against the classical modelling approach, while advantages and disadvantages of the Bayesian methodology are discussed. It is shown that the implemented Bayesian Gaussian process model can infer the typical characteristics of the AEDB from the available datasets, while having comparable prediction qualities as the reference model. Observed differences in the variance and bias characteristics are discussed for both models

Integration of SAR Data Into Monitoring of the 2014-2015 Holuhraun Eruption, Iceland: Contribution of the Icelandic Volcanoes Supersite and the FutureVolc Projects

We report how data from satellite and aerial synthetic aperture radar (SAR) observations were integrated into monitoring of the 2014–2015 Holuhraun eruption in the Bárðarbunga volcanic system, the largest effusive eruption in Iceland since the 1783–84 Laki eruption. A lava field formed in one of the most remote areas in Iceland, after the propagation of a ∼50 km-long dyke beneath the Vatnajökull ice cap, where the Bárðarbunga caldera is located. Due to the 6 month duration of the eruption, mainly in wintertime, daily monitoring was particularly challenging. During the eruption, the European volcanological project FutureVolc was ongoing, allowing collaboration of many European experts on volcano monitoring activities. Icelandic volcanoes are also a permanent Supersite within the Geohazard Supersites and Natural Laboratories (GSNL) initiative, with support from the Committee on Earth Observation Satellite (CEOS) in the form of a large collection of SAR images. SAR data were acquired by Cosmo-SkyMed (CSK) and TerraSAR-X (TSX) satellites and complemented by aerial SAR images. The large set of SAR satellite data significantly contributed to the daily monitoring during the unrest at Bárðarbunga caldera, the Holuhraun eruption and the year following the eruption. Detection of surface changes using both SAR amplitude and phase information was conducted throughout the whole duration of the volcano-tectonic event, and in the following months, to quantify and track the evolution of volcanic processes at Holuhraun and geothermal activity at Bárðarbunga volcano. Combination of SAR data with other data sets, e.g., satellite optical images and geodetic Global Positioning System (GPS) measurements, was essential for the evaluation of the volcanic hazard in the whole area. International collaboration within the FutureVolc project formed the basis for successful analyses and interpretation of the large SAR data set. Information was provided at Scientific Advisory Board meetings of the Icelandic Civil Protection and used in decision-making, as well as for supporting field-deployment and air-based surveys

A new 3MW ECRH system at 105 GHz for WEST

The aim of the WEST experiments is to master long plasma pulses (1000s) and expose ITER-like tungsten wall to deposited heat fluxes up to 10 MW/m$^2$. To increase the margin to reach the H-Mode and to control W-impurities in the plasma, the installation of an upgraded ECRH heating system, with a gyrotron performance of 1MW/1000s per unit, is planned in 2023. With the modifications of Tore Supra to WEST, simulations at a magnetic field B$_0$∼3.7T and a central density n$_{e0}$∼6 × 10$^{19}$ m$^{−3}$ show that the optimal frequency for central absorption is 105 GHz. For this purpose, a 105 GHz/1MW gyrotron (TH1511) has been designed at KIT in 2021, based on the technological design of the 140 GHz/1.5 MW (TH1507U) gyrotron for W7-X. Currently, three units are under fabrication at THALES. In the first phase of the project, some of the previous Tore Supra Electron Cyclotron (EC) system components will be re-installed and re-used whenever possible. This paper describes the studies performed to adapt the new ECRH system to 105 GHz and the status of the modifications necessary to re-start the system with a challenging schedule

Capabilities of Gossamer-1 derived small spacecraft solar sails carrying MASCOT-derived nanolanders for in-situ surveying of NEAs

Any effort which intends to physically interact with specific asteroids requires understanding at least of the composition and multi-scale structure of the surface layers, sometimes also of the interior. Therefore, it is necessary first to characterize each target object sufficiently by a precursor mission to design the mission which then interacts with the object. In small solar system body (SSSB) science missions, this trend towards landing and sample-return missions is most apparent. It also has led to much interest in MASCOT-like landing modules and instrument carriers. They integrate at the instrument level to their mothership and by their size are compatible even with small interplanetary missions. The DLR-ESTEC Gossamer Roadmap NEA Science Working Groups‘ studies identified Multiple NEA Rendezvous (MNR) as one of the space science missions only feasible with solar sail propulsion. Parallel studies of Solar Polar Orbiter (SPO) and Displaced L1 (DL1) space weather early warning missions studies outlined very lightweight sailcraft and the use of separable payload modules for operations close to Earth as well as the ability to access any inclination and a wide range of heliocentric distances. These and many other studies outline the unique capability of solar sails to provide access to all SSSB, at least within the orbit of Jupiter. Since the original MNR study, significant progress has been made to explore the performance envelope of near-term solar sails for multiple NEA rendezvous. However, although it is comparatively easy for solar sails to reach and rendezvous with objects in any inclination and in the complete range of semi-major axis and eccentricity relevant to NEOs and PHOs, it remains notoriously difficult for sailcraft to interact physically with a SSSB target object as e.g. the Hayabusa missions do. The German Aerospace Center, DLR, recently brought the Gossamer solar sail deployment technology to qualification status in the Gossamer-1 project. Development of closely related technologies is continued for very large deployable membrane-based photovoltaic arrays in the GoSolAr project. We expand the philosophy of the Gossamer solar sail concept of efficient multiple sub-spacecraft integration to also include landers for one-way in-situ investigations and sample-return missions. These are equally useful for planetary defence scenarios, SSSB science and NEO utilization. We outline the technological concept used to complete such missions and the synergetic integration and operation of sail and lander. We similarly extend the philosophy of MASCOT and use its characteristic features as well as the concept of Constraints-Driven Engineering for a wider range of operations

Small Spacecraft Based Multiple Near-Earth Asteroid Rendezvous and Landing with Near-Term Solar Sails and ‘Now-Term‘ Technologies

Physical interaction with small solar system bodies (SSSB) is the next step in planetary science, planetary in-situ resource utilization (ISRU), and planetary defense (PD). It requires a broader understanding of the surface properties of the target objects, with particular interest focused on those near Earth. Knowledge of composition, multi-scale surface structure, thermal response, and interior structure is required to design, validate and operate missions addressing these three fields. The current level of understanding is occasionally simplified into the phrase, ”If you’ve seen one asteroid, you’ve seen one asteroid”, meaning that the in-situ characterization of SSSBs has yet to cross the threshold towards a robust and stable scheme of classification. This would enable generic features in spacecraft design, particularly for ISRU and science missions. Currently, it is necessary to characterize any potential target object sufficiently by a dedicated pre-cursor mission to design the mission which then interacts with the object in a complex fashion. To open up strategic approaches, much broader in-depth characterization of potential target objects would be highly desirable. In SSSB science missions, MASCOT-like nano-landers and instrument carriers which integrate at the instrument level to their mothership have met interest. By its size, MASCOT is compatible with small interplanetary missions. The DLR-ESTEC Gossamer Roadmap Science Working Groups‘ studies identified Multiple Near-Earth asteroid (NEA) Rendezvous (MNR) as one of the space science missions only feasible with solar sail propulsion. The Solar Polar Orbiter (SPO) study showed the ability to access any inclination, theDisplaced-L1 (DL1) mission operates close to Earth, where objects of interest to PD and for ISRU reside. Other studies outline the unique capability of solar sails to provide access to all SSSB, at least within the orbit of Jupiter, and significant progress has been made to explore the performance envelope of near-term solar sails for MNR. However, it is difficult for sailcraft to interact physically with a SSSB. We expand and extend the philosophy of the recently qualified DLR Gossamer solar sail deployment technology using efficient multiple sub-spacecraft integration to also include landers for one-way in-situ investigations and sample-return missions by synergetic integration and operation of sail and lander. The MASCOT design concept and its characteristic features have created an ideal counterpart for thisand has already been adapted to the needs of the AIM spacecraft, former part of the NASA-ESA AIDA mission. Designing the combined spacecraft for piggy-back launch accommodation enables low-cost massively parallel access to the NEA population