• Current Industrial and Technological Trends in Aerospace
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• v.8 no.2
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• pp.54-64
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• 2010

A spacecraft contends with various vibration from the launch to the on-orbit operation, which is one of the major considerations in spacecraft design. The weight reduction has been indispensable to decrease the launch cost, however it produces worse disturbances for the spacecraft equipments. Besides, the load requirements at observation payload interfaces have became severe to secure their pointing stability as their images are required with high resolution. As a possible solution, a vibration isolation system is introduced and it reduces the vibration from the launch vehicle or isolates the spacecraft equipments from their generating/transmitted vibration. In this paper, it is examined the design consideration needed for the accommodation of the vibration isolation systems through the survey of recent applications of vibration mitigation technologies to spacecrafts.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.10
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• pp.853-861
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• 2012

This paper considers one of the explicit guidance algorithms, which has been proposed by Jaggers, to determine the closed-loop guidance algorithm for upper stages of a 3-staged space launch vehicle. Its commanded thrust vector is closer to the optimal solution when compared with that obtained by using the well-known Powered Explicit Guidance (PEG), which has been developed through the Space Shuttle program. Its performance is evaluated here by applying for guidance of the launcher during the second and third stages. Furthermore, to generate more precise guidance commands, it is attempted not to use the approximate formulas for the derivation of the original guidance law, and it is shown that performance is improved in comparison with the original.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.273-277
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• 2009

An oxidizer tunnel-type pipe, which shall transport oxidizer from an oxidizer tank to a turbo-pump of an engine, studied is installed through a fuel tank located under an oxidizer tank. A tunnel-type pipe can save weight compared to a detour-type pipe, however may vary the temperature of fuel stored in a fuel tank because of a broad heat transfer area. Hence in this study the characteristics of main oxidizer pipe and thermal propagation from oxidizer to a fuel tank are monitored by a cryogenic performance test with a tunnel-type pipe. In addition, the possibility of adaptation of an oxidizer tunnel-type pipe to launcher system is also analyzed.

• Aerospace Engineering and Technology
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• v.10 no.1
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• pp.20-29
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• 2011

There are a lot of electrical and electronic components and pneumatic parts sensitive to vibration and shock in the VEB assembly which KARI directly transports among the KSLV-I upper stage transportation items. So, the special attention in the transportation is required. The transportation container with the apparatus for controlling environment was made in order to meet the requirements. The transportation tests using the engineering model were performed 4 times to verify the performance of the transportation container and to conform the transportation conditions(transportation velocity, route, etc.). In this document, the previous transportation history of the VEB assembly, the overview and the result of the KSLV-I FM unit 2 VEB assembly transportation are described.

• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.69-74
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• 2010

As a part of development process of the COMS, an acoustic vibration test was performed in order to verify that the COMS is safe from the acoustic loads coming from the Ariane-5ECA launch vehicle when it is launched. In this paper, the acoustic vibration test preparation which was performed during the development of the COMS is explained, and through the evaluation of the test results, it was verified whether the COMS is safe from the acoustic load that the COMS will experience during the launch. Through detail evaluation of the acoustic loads on the solar array, Ka band communication payload antenna and feed, GOCI(Geo-Stationary Ocean Color Imager), MI(Meteorological Imager), it was confirmed that the COMS is safe from the acoustic loads from launch vehicle.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.8
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• pp.591-597
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• 2022

In this paper, we analyzed linkbudget with comparing actual received level of telemetry system at Palau Tracking Station. Because Palau Tracking Station participated in the launch mission for the first time and lack of verification tests for antenna tracking and signal reception performance, we analyzed the linkbudget more accurately by predicting transmit antenna polarization gain according to the trajectory and attitude of launch vehicle. The analysis results were used to analyze signal reception range, antenna operation angle and LHCP/RHCP received level. The actual received level of the antenna was similar to the linkbudget result as a result of the launch mission operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.3
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• pp.257-264
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• 2015

The structure of SpaceEye-1 developed by Satrec Initiative is designed to carry out various earth observation missions in harsh launch and orbit environments. This paper describes methodology of the structure design and analysis performed during the SpaceEye-1 development. The SpaceEye-1 structure is designed not only to endure the static/dynamic loads but also to protect a main payload and all other components under the launch environments. The structural design requirements were derived from the requirements of the launch vehicle, payload, and other subsystems from the initial development phase. Three-dimensional modeling process was used to verify geometric compatibility of the structure with the other subsystems, and finite element analysis was used to confirm whether the designed structure satisfied all the mechanical requirements derived from the launch vehicle and payload.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.5
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• pp.367-375
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• 2017

RANS computational analysis was performed on the head of the launch vehicle including the hammerhead nose pairing in the supersonic regime. The two-dimensional axisymmetric analysis was performed by using laminar, fully turbulent and transition models and compared with the experimental data. It was observed that different flow phenomena occurred depending on the Reynolds number. Under the high Reynolds number condition, the boundary layer becomes turbulent, which is not separated from the surface of the launch vehicle. With the low Reynolds number condition, laminar separation bubble was produced due to the separation and reattachment of the boundary layer on the expansion-compression edge of the hammerhead type nose fairing. The three-dimensional computations with the angle of attack showed a fully detached vortical structure due to the laminar separation bubble. It is proved that the turbulent transition should be considered to predict the separation bubble with the Reynolds number.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.797-800
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• 2011

For the space launch vehicle, propulsion system is the most important subsystem among others. For the evaluation of development level for rocket engine, integrated system test performed in appropriate facility is needed. In this study, test article and major parameters for certifying the propulsion system of launch vehicle were reviewed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.115-118
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• 2009

Life time and number of use of liquid propellant rocket engine (LRE) should be carefully defined since those are crucial parameters affecting development costs and period. The present study surveyed the development and qualification records of LRE for space launch vehicles, especially concerning about test numbers and duration. It was shown that a single engine for expendable launch vehicle is tested with tens of ignition and several times duration of flight at least.