Jae-Deuk Lee

Technical Papers : Implementaion of KSR-3 Range Safety System

This paper describes the devlopment and implementation for the KOMPSAT-1 scheduling & automatic command plan generator(KSCG). Some problems in mission planning and command planning had occurred using the mission & command planning s/w in MAPS(Missin Analysis and Planning Subsystem) during the LEOP(Launch & Early Orbit Phase) & early normal mission phase due to lots of manual input process and non-automatic process. Therefore, the more mission operations for KOMPSAT-1. In order to prevent the development of new one(KSCG) which should reduce the manual process and generate automatically the command plan has been needed. As a result, the mission operations of KOMPSAT-1 has greatly became stable and more effient.

RF Link Analysis of Improvement in Tracking Range for KSLV-I's Tracking System

This paper presents the RF link prediction results for tracking system of KSLV(Korea space launch vehicle)-I especially, these are compared in terms of both the feeding methods of two onboard antennas and the antenna polarization of ground radar. According to dynamic link results considering the trajectory and attitude of launcher, onboard switching technique and radar circular polarization improve link stability and margin, and furthermore increase maximum tracking range.

Analysis of radiation patterns of inverted-F antenna on a cylindrical conducting body like a satellite launcher

Radiation patterns are analyzed for inverted-F antennas (IFAs) on a cylindrical conducting body like a satellite launcher. Especially, radiation patterns of IFAs on a cylindrical conducting body are simulated and quantitatively analyzed according to the number of IFAs, the length and the diameter of the cylindrical conducting body, and polarization of the antenna for reception in the ground system. IFAs are fabricated and their return losses and radiation patterns are measured. Good agreements are observed between the simulated and measured results. Finally, the effect of gain patterns on the system link is simulated for KSLV (Korea Space Launch Vehicle)-I to be launched in the near future.

Development of On Board Pyro-Shock Recorder for Launch Vehicle

Pyro-shock measurement system in launch vehicle is necessary to validate structural robustness and to prepare environmental qualification criteria for launch vehicle systems. This paper describes design, development and function test of prototype pyro-shock recorder to be employed on KSLV-I in the near future. Due to the limitation of telemetry transmission rate, pyro-shock recorder acquires and stores the shock sensor data with high sampling rate in short period and sends the data to the KSLV-I telemetry system with lower data rate. Signal conditioning in pyro-shock recorder is designed to enhance signal-to-noise ratio through proper placement of anti-aliasing filter.

Design and Test of On-Board Flight Data Acquisition System based on the RS485 Star Network

This paper describes on-board decentralized data acquisition system that acquires and encodes the numerous sensor data distributed on the big flight vehicles efficiently. The system`s sub-units which have one encoder unit and several remote units were designed and simulated according to the communication protocols and the control, sequence logics based on the FPGA chip. And we have made the functional verification of the acquisition, collection and formatting of remote analog and digital data for the manufactured hardwares.

A Study on the Telemetering Results of KSR-III Flight Test

Korea Sounding Rocket(KSR)-III onboard telemetry system has acquired various data from subsystems and sensors in the rocket, and radiated PCM/FM data using two S-band antennas during the flight. Simultaneously， it is necessary that the ground receiving systems track the rocket, and receive and decode telemetry data. Also post processed telemetry data are needed to be broadcasted on ethernet network in real time. Range safety display system displays flight trajectory using telemetry data in mission control center, and so flight manager makes a decision for flight termination from the trajectory This paper describes operating technique about telemetry reception, the development for the realtime data processing system, and the results for telemetering reception on fight test. We telemetered, processed, and broadcasted numerous telemetry data during the flight test successfully.