The thermal deformation was evaluated for the large-scale telescope system composed of segmented mirrors and support structures. Structural Thermal Optical Performance (STOP) analysis was performed to obtain thermal deformation characteristics by modeling the entire structure of a segmented mirror system. In addition, a simple numerical model was proposed to calculate the bending-moment and the buckling factor of a flexure support structure, which has an important role in the performance of the optical system. The calculated results were compared with FEA. From the results of STOP analysis, the large thermal deformation was observed due to temperature gradient caused by sunlight exposure at the long CFRP cylindrical truss that supports the secondary mirror. Regarding the bending moment and the buckling factor of the flexure support structure, FEA results and theoretical solutions showed a good agreement. The constructed models and procedures are effective for quantifying and managing the amount of thermal deformation of the entire segmented mirror structure in the initial design phase.

Electrification of aircraft fuel systems is one of the important factors to achieve CO₂ emission reduction targets for civil aviation. Aircraft systems are commonly expected to make not only simplified configuration and improvement of controllability, but also safety and reliability. The electrification of fuel system also requires the similar approach. Therefore, a simple and reliable redundancy concept is a crucial challenge. Redundant Electric Fuel Metering System (rEFMS) is a possible solution for the concept. Although control performances of rEFMS in normal operations have been investigated, rEFMS behavior in failure events, such as error of flow rate, and fault-tolerant design have not been sufficiently discussed. In this study, we apply a tool of model-based development (MBD) to investigate the system behavior in failure events, which is difficult to acquire with actual equipment. Also, we propose fault-tolerant control methods for most likely failure events. The proposed methods enable us to keep safely fuel supply even in failure events.

The CARATS roadmap aims to design a model for converting meteorological information into airspace and airport capacity. In order to quantify the capacity of Haneda Airport, which has the largest number of domestic flights, the frequency of arrival and departure aircrafts was calculated by timeline diagrams. A temporary decrease in the number of arrival aircrafts was observed during the time period when severe weather had already recovered and no significant weather phenomena were observed. It should be noted that even if throughput capacity of Haneda Airport is not reduced, the number of aircraft arrivals may decrease. This paper explores the causes of the decline in the number of arrival flights by surveying the meteorological data at Haneda Airport with showing flight times and turnaround aircrafts at domestic airports. Since delays are propagated by aircraft turnarounds, so if flights can be shifted from dense traffic periods to sparse traffic periods after the recovery of severe weather, delays can be expected to be reduced. Measures to maintain high throughput and promote delay recovery at Haneda Airport are discussed in this paper.

In this study, we tried to construct a pilot model by applying Generative Adversarial Imitation Learning, a practical method for imitating expert behavior, to the horizontal steady flight and landing problems of aircraft. Maneuvering data were collected from expert pilots through flight simulation experiments and used Generative Adversarial Imitation Learning to train a controller based on deep neural networks. In constructing the landing model, it was found to be effective to separate and combine the approach and flare modes. We successfully obtained the pilot model which captures the characteristics of expert pilot. Furthermore, we evaluated the pilot model's performance through Monte Carlo simulations, providing a quantitative assessment of its applicability and reliability.

The challenge for the development of ion and Hall thrusters using alternative propellants is to realize a corrosion-resistant 100mA-class cathode. As a candidate, a thermionic cathode using lanthanum hexaboride (LaB₆) as an electron emitter has been studied. One of the disadvantages of thermionic cathodes is high power consumption due to radiation heat loss. In this study, a LaB₆ thermionic cathode with Multilayer insulator (MLI) was developed, and thermal performance was evaluated by emission spectroscopy and thermal model analysis. As a result, a LaB₆ temperature of 1802K was achieved with a heating power of 102 W. A comparison of the thermal model calculations, which were in good agreement with the experimental results, showed that MLI reduced the heating power by up to 77%. The thermal model analysis suggested that the performance of 38W of heating power and 100mA of thermionic current could be achieved by increasing the number of MLI layers and reducing the gaps.