Spacecraft-to-spacecraft radio occultations experiments are being conducted at Mars between Mars Express (MEX) and Trace Gas Orbiter (TGO), the first ever extensive inter-spacecraft occultations at a planet other than Earth. Here we present results from the first 83 such occultations, conducted between 2 Nov 2020 and 5th of July 2023. Of these, 44 observations have to-date resulted in the extraction of vertical electron density profiles. These observations are the successful results of a major feasibility study conducted by the European Space Agency to use pre-existing relay communication equipment for radio science purposes. Mutual radio occultations have numerous advantages over traditional spacecraft-to-ground station occultations. In this work, we demonstrate how raw data are transformed into electron density values and validated with models and other instruments.@en

Despite the growing importance of planetary Space Weather forecasting and radiation protection for science and robotic exploration and the need for accurate Space Weather monitoring and predictions, only a limited number of spacecraft have dedicated instrumentation for this purpose. However, every spacecraft (planetary or astronomical) has hundreds of housekeeping sensors distributed across the spacecraft, some of which can be useful to detect radiation hazards produced by solar particle events. In particular, energetic particles that impact detectors and subsystems on a spacecraft can be identified by certain housekeeping sensors, such as the Error Detection and Correction (EDAC) memory counters, and their effects can be assessed. These counters typically have a sudden large increase in a short time in their error counts that generally match the arrival of energetic particles to the spacecraft. We investigate these engineering datasets for scientific purposes and perform a feasibility study of solar energetic particle event detections using EDAC counters from seven European Space Agency Solar System missions: Venus Express, Mars Express, ExoMars-Trace Gas Orbiter, Rosetta, BepiColombo, Solar Orbiter, and Gaia. Six cases studies, in which the same event was observed by different missions at different locations in the inner Solar System are analyzed. The results of this study show how engineering sensors, for example, EDAC counters, can be used to infer information about the solar particle environment at each spacecraft location. Therefore, we demonstrate the potential of the various EDAC to provide a network of solar particle detections at locations where no scientific observations of this kind are available.

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At the OCI Nitrogen ammonia plant, located at the Chemelot site in Geleen, The Netherlands, a project has been initiated to monitor major accident processes at the site. This contribution answers the question whether indicators can be derived from the barrier system status to provide information about the development and likelihood of the major accident processes in the ammonia production process. The accident processes are visualized as scenarios in bowties. This research focuses on the status of the preventive barriers on the so called ‘left-hand side’ of the bowtie, before a hazard becomes uncontrollable. Both the quality – expressed in reliability/availability and effectiveness – and the activation of the barrier system give an indication of the development of the accident scenarios and the likelihood of the central event. This likelihood is calculated as a loss of risk reduction compared to the original design. The calculation gives in an indicator called “preventive barrier indicator”, which should initiate further action. Based on an example, it is demonstrated which actions should be taken and their urgency.@en

In The Netherlands, there are six large (petro)chemical clusters. Companies in these clusters are located next or close to each other. The policy of the Dutch government is to invest in these clusters, and to stimulate their growth. However, there is little scientific evidence that a cluster of (petro)chemical companies is safer than stand-alone (petro)chemical companies. This research, with an exploratory design, investigates parameters influencing safety of (petro)chemical clusters and stand-alone (petro)chemical companies. Insight into these parameters can lead to targeted initiatives (e.g. by government and companies) to improve safety in both clusters and stand-alone companies. Stimulating cooperation and sharing of knowledge is an important parameter, both in clusters and between clusters, and with non-clustered companies. Information exchange on accident scenarios between adjacent (petro)chemical companies with and without domino-designation requires extra attention. An overarching cluster body can contribute to a more safe, proactive and strategic cooperation. Furthermore, it is important that cluster policies include more than only spatial planning and external safety. Also after the establishment of clusters, companies should not be treated as individual companies, but as companies being part of a cluster, for instance when inspections are performed. Attention is needed for both domino-A nd escalation-effects, and possible domino-effects with (petro)chemical companies in clusters (just) below the Seveso-threshold. Integrated plants falling under the management of different companies require an adjusted approach to optimise safety.

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Procesveiligheidsindicatoren geven informatie over ongevalsscenario’s en over de effectiviteit van veiligheidsbarrières. Dat is de bedoeling. Het is de vraag of dat lukt. In de vakliteratuur wordt een onderscheid gemaakt tussen leidende (leading) en volgende (lagging) indicatoren. Dit lijkt overtuigend. Behalve bedrijven gebruikt ook de overheid deze indeling. Indicatoren worden vaak gekwantificeerd. Wat betekent dat getal? Veiligheidsindicatoren zijn ook binnen arbeidsveiligheid een onderwerp. Deze bijdrage beperkt zich voornamelijk tot indicatoren in procesveiligheid en in high-tech-high-hazard-sectoren. Het onderwerp veiligheidsindicatoren zal nog lang in de belangstelling blijven staan.@en