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Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease.

Solid rocket launch vehicles are an important component of the space transportation system and have made significant contributions to China’s commercial satellite space launch industry in the past five years. Trajectory design plays a crucial role in the overall design of rockets and runs through the entire process of the overall design. For the state where the initial payload of the carrier rocket is 280kg, the first and second stage separation dynamic pressure constraints of 18kPa, 19kPa and 20kPa were selected in the design and optimization. Starting from the aspects of trajectory design and optimization, separation safety, and attitude control stability, the influence analysis of the dynamic pressure of the separation between the first and second stages of the rocket on the flight trajectory was carried out. The research shows that as the dynamic pressure of the separation of the first and second stages of the rocket increases, the total velocity loss of the rocket decreases and the carrying capacity is enhanced. The maximum carrying capacities in the three states are 282.11kg, 285.80kg and 289.35kg respectively. Limited by the control capability, the high-altitude wind speeds that the rocket can adapt to under the three constrained design states are 75m/s, 45m/s and 22m/s respectively.

NASA is in the processes of evaluating various architectures that may support human missions to Mars. A multitude of concepts are being traded and associated sensitivities are being analyzed. Among these trades, several options for Mars Ascent Vehicle (MAV) propellant supply are being considered. Due to mass constraints on the Mars descent system and the in-space transportation system, landing a fully fueled MAV, that can launch humans from the surface of Mars, presents significant integrated architecture challenges. Consequently, MAV propellant must either be pre-positioned and transferred across the surface robotically or made on the surface via In-Situ Resource Utilization (ISRU) techniques. In each case, there are implications to the number of architecture elements, total system mass, power requirements, complexity of operations, and required technology developments. An analysis that compares an ISRU point solution to a similar point solution that pre-positions and transfers propellant is detailed.

Optimization solutions of real-world engineering problems mainly suffer from the large computational cost, the curse of dimensionality, and the multi-disciplinary nature of the involved disciplines. These issues may be intensified by incorporating uncertainties into the design and optimization of the problem. In this context, Surrogate-Assisted Optimization (SAO) methods and Evolution Control Strategies (ECS) have been considered as powerful paradigms to overcome or at least to alleviate the mentioned issues over the last two decades. This paper presents a novel ECS strategy based on the meta-models along with the real models. This strategy calculates the accuracy of the meta-model at each design point and determines if the real-model needs to be replaced with the meta-model. Moreover, the SAO and ECS are integrated to develop an augmented strategy to solve complex problems like Uncertainty-based Multidisciplinary Design Optimization (UMDO). In this context, the artificial neural networks are used along with the improved Latin hypercube sampling technique. Performance benefits of the proposed strategy in achieving the near-global optimum solution are shown by solving two simple mathematical problems and an engineering benchmark problem. To demonstrate the potential capability of this strategy, it applies to the UMDO problem of a space transportation system. Simulation results illustrate that the proposed strategy improves the computational efficiency as well as the globality of the optimal solution by proper management of the meta-models and real-models within the optimization process.

A model of a NUAA-PTRE pre-cooled air turbine engine was established. The design point parameters of the engine were optimized, including the pressure ratio, air flow rate of the compressor, efficiency, throat area, and efficiency of the turbine. The air flow rate at the engine operating point was 142.73 kg/s. High performance of the key components under a wide range of working conditions was realized after optimization. To achieve the indicators of the overall scheme, adaptability studies of key components were conducted. A three-stage variable geometry design was applied to the inlet. The pre-cooler was optimized with a power-to-weight ratio of over 100 kW/kg and a compactness of 278 m2/m3. The built-in rocket gas generator and dual-component injector were developed, and the combustion and heat transfer processes were simulated. The overall optimization design of the NUAA-PTRE and the adaptive design of the components were completed, and high performance of the engine in a wide range of flight conditions at Ma 0~5 and altitude 0~25 km was achieved.

Theoretical approaches to the construction of a spectrometric diamond detector of fluxes of ionizing radiation are considered. The device is intended for continuous monitoring of the radiation conditions onboard space vehicles for quickly arriving at decisions as regards active protection and prediction of the remaining life of space transportation systems.

Description As the Earth's population grows and migrates, air and space travel as we currently know it will have to change to meet the requirements of a new society. This exciting book looks at the possibilities and probabilities of future air and space travel. It reports on the latest experimental research, including up-to-date artists' renderings, color plates, and more than 200 figures and tables. It also details applications for these new systems and vehicles.

To build a sustainable and affordable space transportation system for human space exploration, the design and deployment of space infrastructures are critical; one attractive and promising infrastructure system is the in-situ resource utilization (ISRU) system. The design analysis and trade studies for ISRU systems require the consideration of not only the design of the ISRU plant itself but also other infrastructure systems (e.g., storage, power) and various ISRU architecture options (e.g., resource, location, technology). This paper proposes a system-level space infrastructure and its logistics design optimization framework to perform architecture trade studies. A new space infrastructure logistics optimization problem formulation is proposed that considers infrastructure subsystems' internal interactions and their external synergistic effects with space logistics simultaneously. Since the full-size version of this proposed problem formulation can be computationally prohibitive, a new multi-fidelity optimization formulation is developed by varying the granularity of the commodity type definition over the network graph; this multi-fidelity formulation can find an approximation solution to the full-size problem computationally efficiently with little sacrifice in the solution quality. The proposed problem formulation and method are applied to a multi-mission lunar exploration campaign to demonstrate their values.