• Journal of the Korean Society of Propulsion Engineers
• /
• v.6 no.3
• /
• pp.45-52
• /
• 2002

This article deals with the introduction of longitudinal instability of liquid rocket (pogo) and the analytical results on the frequency responses of Korean Sounding Rocket (KSR-III) propulsion feeding system. Both the stiffness of bellows and the cavitation volume of venturi affect the frequency response of the feeding system. Especially, bellows has a great roll to reduce the natural frequency of the feeding system. Also, oxidizer and fuel feeding systems of the KSR-III have natural frequencies of about 280Hz and 90Hz, respectively.

• Aerospace Engineering and Technology
• /
• v.1 no.1
• /
• pp.117-127
• /
• 2002

In this paper, structure design of the payload section of the KSR-III was performed. The payload section of the KSR-III, which corresponds to the second stage, consists of the Scientific Payload Section for the mission of the rocket, the Payload Section (Electronics) for the communication between the rocket and the ground station, and the Payload Section (Attitude Control) for the attitude control of the rocket. In order to accomplish the mission, every payload and component should operate successfully during the mission period and the structure must satisfy the requirements of the payloads. In this research, precise composition of the payload section and payloads arrangement of the KSR-III were performed. And the modification of the structure to meet the requirements were described.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.8
• /
• pp.54-63
• /
• 2004

The inner surface temperatures of the KSR-III Sounding Rocket launched at 29th November 2002 were measured in the flight test, and the aerodynamic heating rate and outer surface temperature were calculated. The used program is the MINIVER code, which calculate the boundary layer equation based on the theoretical analysis, and its calculation is simulated on the flight time histories. The analysis considered the inner surface heat transfer with one dimensional solid heat conduction. The results showed that the major interior heat transfer is the radiation heat transfer, and the maximum outer surface temperature due to aerodynamic heating reached to $223^{\circ}C$ at fin and the maximum heating rate is about $133kW/m^2$ at nose cap. The whole analysis proved that the surface temperature remained below the allowable temperature, and the KSR-III thermal design satisfies the thermal environmental conditions.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.4
• /
• pp.80-87
• /
• 2004

To understand the each performance parameter correlation of flight type liquid-propellant rocket engine for KSR-III(Korea Sounding Rocket-III), the analysis of engine stand-alone combustion test results was carried out. Considering the variation of ablative material combustion chamber caused by erosion, linear regression analysis that ignores oxidizer/fuel ratio effect and two-variable 2nd-order polynomial regression analysis that considers oxidizer/fuel ratio change were performed. It can be described that linear regression analysis is simple and very practical method, and can predict the performance within 1% error inside analyzed region. And two-variable 2nd-order polynomial regression analysis can predict with very high accuracy inside region and shows that KSR-III engine's optimum oxidizer/fuel ratio for thrust(or specific impulse) is 2.22 and that for combustion chamber pressure(or characteristic velocity) is 2.17.

• Aerospace Engineering and Technology
• /
• v.2 no.1
• /
• pp.140-152
• /
• 2003

Scenario is a guiding principle of launch operation and control for rocket and ground support system. Therefore, developing a scenario is the first step to prepare for rocket launch, which is a critical task for success of KSR-III flight test. The launch scenario for KSR-III flight test is a procedural sequence of command and control signals to be given to rocket and ground support systems. In this paper, the UML object modeling method is applied to development of a launch scenario. First, the subsystems of the launch system are modeled by objects, and then the interfaces between each two subsystems are modeled by association links. The finally obtained object diagram of KSR-III launch system is used to analyzing flow of data and commands and control signals, and interactions. The scenario includes the sequences of pre-launch/launch operations and emergency operations.

• Aerospace Engineering and Technology
• /
• v.1 no.2
• /
• pp.105-112
• /
• 2002

In this paper, a servo filter design for the gimbal engine actuator system of KSR-III(Korea Sounding Rocket-III) is considered. A reasonable filter structure is determined based on the actuator analytic models. The servo filter consists of a 2-nd order lowpass filter and a 1-st order compensator. The lowpass filter is required to protect the actuator from high frequency vibration, and the compensator to enhance the resulting stability. A Butterworth type servo filter is considered as the simplest one. The final servo filter type is determined by evaluating simultaneously both high frequency gain reduction performance and the corresponding KSR-III stability margin. Consequently it is revealed that a notch type servo filter located on the error between command signal and feedback signal in the control loop is very effective. Later, based on the proposed servo filter type, an onboard servo filter hardware of KSR-III will be designed and tested.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2002.10a
• /
• pp.6-6
• /
• 2002

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.05a
• /
• pp.546-551
• /
• 2001

Space Test Department at KARI(Korea Aerospace Research Institute) plans to carry out the GVT(Ground Vibration Test) for the KSR(Korea Sounding Rocket)-III FM(Flight Model) which is being developed by Space Technology R＆D Division. KSR-III will be an intermediate to the launch vehicle capable of carrying satellites to their orbits. GVT offers very important information to predict the behavior of KSR in its operation, and to develop the flight control and aerodynamic analysis. For development of test facilities, testing and analysis methods which can be used for the future test, Space Test Department has performed the GVT with KSR-II PFM(Proto-Flight Model) at Satellite Integration ＆ Test Center of KARl This paper discusses the procedures, techniques and the results of it. In this test, to simulate free-free condition, test object hung in the air by 4 bungee cords specially devised. The GVT was carried out using pure random excitation technique with MIMO(Multi-Input-Multi-Output) method with three electromagnetic shakers, and poly-reference parameter estimation was used to identify the modal parameters. As the result of the test, 11 mode shapes and modal parameters below 200㎐ were identified and compared with analytical results.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.30 no.7
• /
• pp.113-122
• /
• 2002

Control system modeling and optimal bending filter design for KSR-III (Korea Sounding Rocket III) are performed. Rigid rocket dynamics, aerodynamics, sloshing, structural bending, actuator dynamics, sensor dynamics and on-board computer characteristics are considered for control system modeling. Compensation for time-varying control system parameters is conducted by gain-scheduling. A filter to stabilize bending mode is designed using parameter optimization technique. Resultant attitude control system can satisfy required frequency domain stability margin.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.30 no.6
• /
• pp.116-123
• /
• 2002

This paper describes the development of gimbals engine actuation system for KSR(Korean Sounding Rocket)-III which performs the attitude control of pitch and yaw axes by thrust vector control of liquid propellant gimbals engine. The development requirements of configuration, performance and environment are introduced, and the principles and details of components and system development are discussed. The developed system successfully fulfilled its own performance and environmental evaluation. It will be planned to perform verification of interface and integration compatibility with other related systems, and then mounted on KSR-III as a flight hardware system.