نشریه فناوری در مهندسی هوافضا
سال چهارم شماره 1 (پیاپی 12، بهار 1399)

Igniters are main sections of motor that initiate the ignition of propellant grain. Large motors usually use pyrogen composite igniters. Pyrogen igniters have similar formulation with solid composite propellants, but their burning rate is relatively high. In this research, a composite igniter, based on hydroxyl terminated poly-butadiene, prepared via cast-cure method and effects of 0.02 percent addition of dibutyltin dilaurate, as an organo-metallic cure catalyst, was investigated. Results show that applying the cure catalyst enhance hardness up to 15%. Tensile stress increases vigorously, but elongation reduces 50%. Applying the cure catalyst has also no significant effects on burning rate, but pressure index increases from 0.353 to 0.383.

Electromagnetic compatibility (EMC) is an important subject in electronics and communications. The proper performance of a system is very much dependent on meeting EMC requirements. This is more important in space systems. In this paper, the first part of a two-part text about EMC in space systems is presented. The importance of the subject and the necessity to take the EMC considerations into account from the very beginning phases of the system design is discussed. The three main EMC subject areas: sources of noise, noise transfer paths, and immunity methods are mentioned. The most important global military and space EMC standards are presented. System level actions and design considerations are also mentioned. Theses include: grounding methods, shielding and related topics, such as shielding effectiveness, shield resonance, absorbers, EMC gaskets and issues regarding wirings, cables, and connectors.

In cryogenic tank insulation, different insulators are used, of which multilayer insulation is one of them. Multi-layer insulations have high performance, compared to other cryogenic insulations. These insulations include radiation shields and spacers. Integrated multilayer insulation is a kind of insulation in which the spacer networks are replaced by small polymeric pieces having low thermal conductivity. Load response multi-layer is made of small polymeric columns that respond to external loads. Common multilayer insulation do not have ability of responding to external loads. To overcome this problem, load response multilayer insulations are used. These insulations do not have spacer network, but they are made of polymeric spacers that can withstand external loads and weighst. Composite layered insulation system includes radiation shield layer, powdery layers (aerogel or silica fume), and carrier layers (non-woven or fiberglass paper). The difference between composite layered insulation and conventional multilayer insulations is that the composite insulation has an additional layer of powder in its structure.

This paper aims to assess the socio-economic impacts of space investments. It briefly propses the benefits derived from space programs. Also, it emphasizes the impact of the ever-growing trend of space technology trasfer, space commercialization, and the role of space startups in macroeconomic level. Reviewing the Literature and industry statistics implies the constant increasing trend of space industry development and broader application areas. In this respect, job creation and revenues has been increased in recent years. On the other hand, national and international macroecomic atmosphere have had considerable effects (directly and indirectly) on investments, production and turnover of space industry as a whole. By and large, market trends in recent years have opened new windows to new opportunities and consequently, we will see more effects of space industry on national and international economy.

Ground vibration test (GVT) is one of the standard structural tests required for designed passenger aircrafts. This test is performed to derive the experimental dynamical model of aircraft structure. The process of executing this test involves test planning, structural preparation, data gathering, and extraction of dynamic parameters from the test data. In the present study, the practical implementation process of each step is described. Given the size and complexity of this test, certain techniques, hardware, and software are to be investigated. The global experience of performing this test is briefly discussed. Finally, a typical setup for a ground vibration test of a large aircraft is introduced and described.

Ultraviolet light detection is of interest in astronomy and meteorology because of the useful information it provides. CCD's based on UV detectors do not require any longer wavelength filters.In this case, UV light can be directly detected and therefore the effective sensitivity of CCD can be effectively increased. The high radiation tolerance is a very critical factor (especially for the detectors used in outer space) in addition to other basic detector parameters, such as quantum efficiency, dark current, and optical current, Radiative environment, by changing the properties of the materials and devices that create the photodetector, can gradually deteriorate its performance and therefore causes malfunction and limitation in the application of photodetectors. In this article, we initially deal with different types of UV detectors and their general characteristics, then the AlN based photodiode and the effect of radiation on its parameters is introduced and discussed. Eventually,a  few types of VUV photo-detectors, used in space applications, will be reviewed.