An Automated Constellation Design & Mission Analysis Tool for Finding the Cheapest Mission Architecture

Identifying the optimal mission architecture for a space mission is critical for mission success, especially for large constellations. Here, optimizing the entire mission architecture for cost is necessary for the business case to work. This paper presents an automated system that combines constellation design and mission analysis functions in the context of a distributed engineering environment. It utilizes analytical methods, commercial simulation software and other specialized tools to identify multiple eligible constellations for the user-defined case, perform the associated mission analysis tasks, and provide input for additional tools like cost estimation software to eventually identify the optimal constellation. This allows assessing more options to fulfill the mission in less time, establishing the benefits of each constellation analyzed, and also allows non-expert users to quickly understand and evaluate consequences of design or requirement changes

A small satellite with a dual-frequency heterodyne spectrometer for the detection of atomic oxygen in the atmosphere of Earth

A first step towards realization, a small satellite study for OSAS (Oxygen Spectrometer for Atmospheric Science) has been performed based on Concurrent Engineering methods

Trypanosoma cruzi Epimastigotes Are Able to Store and Mobilize High Amounts of Cholesterol in Reservosome Lipid Inclusions

Reservosomes are lysosome-related organelles found in Trypanosoma cruzi epimastigotes. They represent the last step in epimastigote endocytic route, accumulating a set of proteins and enzymes related to protein digestion and lipid metabolism. The reservosome matrix contains planar membranes, vesicles and lipid inclusions. Some of the latter may assume rectangular or sword-shaped crystalloid forms surrounded by a phospholipid monolayer, resembling the cholesterol crystals in foam cells.Using Nile Red fluorimetry and fluorescence microscopy, as well as electron microscopy, we have established a direct correlation between serum concentration in culture medium and the presence of crystalloid lipid inclusions. Starting from a reservosome purified fraction, we have developed a fractionation protocol to isolate lipid inclusions. Gas-chromatography mass-spectrometry (GC-MS) analysis revealed that lipid inclusions are composed mainly by cholesterol and cholesterol esters. Moreover, when the parasites with crystalloid lipid-loaded reservosomes were maintained in serum free medium for 48 hours the inclusions disappeared almost completely, including the sword shaped ones.Taken together, our results suggest that epimastigote forms of T. cruzi store high amounts of neutral lipids from extracellular medium, mostly cholesterol or cholesterol esters inside reservosomes. Interestingly, the parasites are able to disassemble the reservosome cholesterol crystalloid inclusions when submitted to serum starvation

Application of Automated Design Tools for Satellite Missions with the Design Platform DCEP

Within the project IRAS (Integrated Research Platform for Affordable Satellites), digital tools for the fast and semi-automated early design of space missions are being developed. The constellation design tool TOCASTA (Tool for Constellation and Satellite Trade-off Analysis) identifies possible satellite constellation solutions based on coverage requirements using a semi-analytical method. It uses the commercial simulation software ASTOS to refine solutions for optimized constellation design, and performs an automated mission analysis for each solution, aided by the ESA-DRAMA software. The satellite design tool ESDC (Evolutionary System Design Converger) accelerates spacecraft design using heuristic scaling laws and evolutionary algorithms. These laws, in combination with user-defined requirements, generate estimates for subsystems, while parametric models and component-based dimensioning further predict detailed spacecraft designs. Evolutionary algorithms optimize each configuration to minimize the overall system mass. The Digital Concurrent Engineering Platform DCEP offers a web-based service for cooperative model-based systems engineering, and acts as platform for the software-aided design process by providing an intuitive user interface. It contains a parametric representation of the satellite and manages data transfer and integration of other IRAS- and third-party tools. The tools are coupled to the DCEP via an SSH-based method that allows data linking and management of the tools as well as accessing their results via the DCEP user interface, with minimal effort for the tool providers. As a first test of the coupled system of tools and DCEP, an exemplary satellite mission design has been conducted. The tools were utilized successfully via the DCEP to design several satellite constellations with different coverage requirements and altitudes. Mass and power budgets as well as thruster recommendations for the individual satellites were established for the different constellation solutions. The coupling of DCEP and tools allowed a seamless transfer of TOCASTA output data to the ESDC, enabling the rapid computation and evaluation of a large number of designs. Potential improvements in user experience and beneficial additional features were identified

IRAS: Low-cost Constellation Satellite Design, Electric Propulsion and Concurrent Engineering

The Integrated Research Platform for affordable Satellites (IRAS) is a joint research project by DLR, Fraunhofer, IRS and industry partners aimed at developing cost-reducing technologies for satellites. This paper describes the various contributions of the IRS to IRAS, such as development of a reference satellite constellation for implementation and demonstration of new technologies. The digital concurrent engineering platform as an IRAS subproject is being described with regards to the envisioned aim and future application for unifying engineering tools from multiply stakeholders. It allows to create an efficient design toolchain to reduce development time and costs. The evolutionary system design converger is a contribution on the level of electric propulsion systems to the platform. It is given as a subsystem example of the capabilities of the digital concurrent engineering platform. Additional examples of analysis and outputs are given for the IRAS use case. Grid ion thrusters with xenon are likely to be able to provide an electric propulsion system with the lowest total system mass, while an ammonia based arcjet system will allow for the fastest regeneration of the constellation at a reasonable mass fraction. Additive manufacturing with its significant potential for space hardware cost reduction, while maintaining or increasing system performances due to function integration, is explained. An arcjet nozzle with integrated regenerative cooling channels has been identified as promising component. It is being manufactured from tungsten powder through selective laser melting

IRAS: Low-cost Constellation Satellite Design, Electric Propulsion and Concurrent Engineering

The Integrated Research Platform for Affordable Satellites (IRAS) is a joint research project by DLR, Fraunhofer, IRS, and industry partners aimed at developing cost-reducing technologies for satellites. This paper describes the various contributions of the IRS to IRAS, such as development of a reference satellite constellation for implementation and demonstration of new technologies. The digital concurrent engineering platform as an IRAS subproject is being described with regards to the envisioned aim and future application for unifying engineering tools from multiple stakeholders. It allows to create an efficient design toolchain to reduce development time and costs. The evolutionary system design converger is a contribution on the level of electric propulsion systems to the platform. It is given as a subsystem example of the capabilities of the digital concurrent engineering platform. Additional examples of analysis and outputs are given for the IRAS use case. Gridded ion thrusters with xenon as propellant are likely to be able to provide an electric propulsion system with the lowest total system mass, whereas an ammonia based arcjet system will allow for the fastest regeneration of the constellation at a reasonable mass fraction. Additive manufacturing with its significant potential for space hardware cost reduction, while maintaining or increasing system performances due to function integration, is explained. An arcjet nozzle with integrated regenerative cooling channels has been identified as promising component. It is being manufactured from tungsten powder through selective laser melting. The advantages of using the know how of the automotive industry and translating it into space is described