• Title/Summary/Keyword: Launch Vibration

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DEVELOPMENT OF KITSAT-1 AND 2 MECHANICAL SYSTEM AND RESULTS OF ENVIRONMENT TEST (우리별 1, 2호의 기계구조 개발 및 환경시험 결과)

  • 배정석;이동우;이상현;박성동;최순달
    • Journal of Astronomy and Space Sciences
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    • v.13 no.2
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    • pp.94-104
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    • 1996
  • The satellite experiences the launch environment such as vibration, acceleration, shock induced by rocket and the orbit environment such as high vacuum, no gravity, high temperature and cryogenic. Therefore, the satellite should be designed and manufactured to endure such environments. Also, special care must be taken on the assembly of parts and subsystem. Finally, we describe the environment test of microsatellite to ensure the reliable operation during launch period as well as in-orbit operation.

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Design of Acoustic Resonator Array for Low Frequency Mode Control of Launch Vehicle (위성 발사체 탑재부 저주파 음향 모드 제어를 위한 공명기 배치 설계)

  • Seo, Sang-Hyun;Park, Soon-Hong;Jang, Young-Soon;Yi, Yeong-Moo;Cho, Gwang-Rae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.521-524
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    • 2005
  • To protect a satellite and electronic equipment from the acoustic loads generated by rocket propulsion system, many launch vehicle use acoustic blanket. Most high frequency region of the acoustic loads is reduced by nose fairing skins and acoustic barrier, but low frequency region is not. In order to control low frequency acoustic mode, we designed away resonator panel which was made of composite materials. This paper shows the absorption coefficient measurement result of resonator and SPL(Sound Pressure Level) reduction by using resonators in a rectangular cavity for experiment. Proper arrangement of acoustic resonators at each mode reduce effectively SPL around the satellite through changing boundary condition.

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Analysis of Launching Dynamics Using Finite Element Method (유한요소법을 이용한 발사역학 해석)

  • Lee, Hak-Yeol;Song, Oh-Seop
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.3
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    • pp.13-18
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    • 2008
  • During the launching phase, a launcher is vibrated by launching forces and as a result, the vibrating launcher affects the behavior of the missile. One of the important performances of the launcher is that the launched missile should be in a stable condition at the launching stage. In this paper, the launcher vibration at the launching phase is investigated in order to secure the stable flight of the missile. Using the finite element method, launching dynamics is investigated to analyze the behaviors of the launcher and missile considering the effect of the launcher vibration. In addition, performance of consecutive launching and launching dynamics of the launcher which launches missiles consecutively are studied for the various conditions after first launch.

Drawing up a Noise Map under Launch Environment through Analyzing Jet Noise of Guided Weapon (유도무기의 제트소음 분석을 통한 발사환경에서의 소음지도 작성)

  • Kim, Sang-Min;Park, Woong;Ha, Jae-Hyoun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.163-168
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    • 2011
  • Noise map is drawn up under launch environment through analyzing jet noise of guided weapon in this research. This has an important significance in terms of having an opportunity to look at influence of noise which is caused by guided weapon in the surrounding environment. In this paper, the magnitude of jet noise that was measured by using microphone and the result of numerical analysis that was gained by using ENPro which is environment noise prediction program are shown. At this point estimation of noise source was based on ISO 9613. Finally noise map derived from results mentioned above will become useful material when setting safety guide for protecting hearing loss of operator of weapon system in the future.

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An overview of acoustic and vibration research activities for the structural development of Korean space launchers (위성 발사체 구조 개발을 위한 음향/진동 연구)

  • Park, Soon-Hong
    • The Journal of the Acoustical Society of Korea
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    • v.39 no.4
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    • pp.342-350
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    • 2020
  • Acoustic and vibration research activities for the structural development of Korean space launch vehicles are introduced in this paper. Various dynamic loads exerted on a launch vehicle during its operation are summarized. The acoustical design method of payload fairings which protect satellites from harsh launch environment was reviewed. Several acoustic research activities were performed to enhance the analytical prediction ability during the development period of the Naro and the Nuri launcher. Specifically, the following research activities are reviewed: a test and vibro-acoustic analysis of composite cylinders whose layup properties are varied, a research on low-frequency acoustic load reduction by an acoustic resonator array and an acoustic test on the cylinder part of the Naro payload fairing. A vibro-acoustic analysis result for the Nuri launcher was introduced and predicted acoustic and vibration levels and measured ones are shown to be in a good agreement.

The Analysis of Mechanical Environment of Small Satellite Launcher (소형위성 발사체의 기계적 환경 분석)

  • Lee, Sung-Sae;Park, Jong-Oh;Rhee, Seung-Wu
    • Aerospace Engineering and Technology
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    • v.9 no.2
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    • pp.123-128
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    • 2010
  • Science and Technology SATellite-3 (STSAT-3) is science purpose satellite which weighs below 170kg. This is classified as small satellite or micro satellite more specifically. The launch vehicles (launchers) for small satellite has their own requirements for environmental interface. Since the small satellites are usually launched with cluster or multiple payloads, the selection option for appropriate launcher is limited. Therefore, the satellite should be designed with the consideration of environmental requirements of these launchers. In this paper, the environmental requirement of most candidated launchers for small satellite is summarized and give satellite environmental requirement to accommodate all launchers requirements.

Spacecraft vibration testing: Benefits and potential issues

  • Kolaini, Ali R.;Tsuha, Walter;Fernandez, Juan P.
    • Advances in aircraft and spacecraft science
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    • v.5 no.2
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    • pp.165-175
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    • 2018
  • Jet Propulsion Laboratory has traditionally performed system level vibration testing of flight spacecraft. There have been many discussions in the aerospace community for more than a decade about spacecraft vibration testing benefits or lack thereof. The benefits and potential issues of fully assembled flight spacecraft vibration testing are discussed herein. The following specific topics are discussed: spacecraft screening test to uncover workmanship problems for launch dynamics environments, force- and moment-limited vibration testing, potential issues with structural frequency identification using base shake test data, and failures related to vibration shaker testing and ways to prevent them.

Structural Analysis of Sinusoidal Vibration Load for Liquid Rocket Engine System (액체로켓엔진 시스템 정현파 진동 구조해석)

  • Chung, Yong-hyun;Lee, Eun-seok;Park, Soon-young;Yang, Chang-hwan;Jung, Jin-taeg
    • Journal of Aerospace System Engineering
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    • v.3 no.2
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    • pp.20-23
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    • 2009
  • The structural analysis of liquid rocket engine was performed in the case of sinusoidal vibration load to verify structural safety. The finite element model is composed with main liquid rocket engine components, combustion chamber, turbopump, gas-generator, pyro-starter, main pipes, main valve, heat-exchanger, gimbal-mount and brackets. Natural vibration mode analysis and structural analysis for sinusoidal vibration load were performed. The natural mode frequency of liquid rocket engine is twice than that of launch vehicle. In the case of stress result of sinusoidal vibration load, the part of maximum stress has 1.4 margin, so the engine structure is safe for sinusoidal vibration load.

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On-orbit Micro-vibration Isolation Performance Verification for Spaceborne Cryocooler Passive Vibration Isolator Using SMA Mesh Washer (SMA 메쉬 와셔를 적용한 우주용 냉각기 수동형 진동절연기의 궤도 미소진동 절연성능 검증)

  • Kwon, Seong-Cheol;Jeon, Su-Hyeon;Oh, Hyun-Ung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.25 no.1
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    • pp.24-32
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    • 2015
  • Pulse tube-type spaceborne cryocooler is widely used to cool down the infrared sensor of observation satellites. However, such cryocooler also generates micro-vibration which is the one of main sources to seriously affect the image quality during its on-orbit operation. Therefore, to comply with the mission requirement of high resolution observation satellite, additional technical efforts have been required. In this study, we proposed a spaceborne cryocooler passive vibration isolator using SMA mesh washer, which guarantees the structural safety of both the micro-vibration disturbance source and itself under harsh launch vibration loads without an additional holding mechanism and the micro-vibration isolation performance on orbit environment. To verify the micro-vibration isolation performance of the proposed vibration isolator, we performed the micro-vibration isolation measurement test using the dedicated micro-vibration measurement device proposed in this study.