Search | Korea Science

Lim, Byoungjik;Kim, Cheulwoong;Lee, Keum-Oh;Lee, Keejoo;Park, Jaesung;Ahn, Kyubok;Namkoung, Hyuck-Joon;Yoon, Youngbin
- Journal of the Korean Society of Propulsion Engineers
- /
- v.25 no.2
- /
- pp.119-143
- /
- 2021
Selecting liquid methane as fuel is a prevailing trend for recent rocket engine developments around the world, triggered by its affordability, reusability, storability for deep space exploration, and prospect for in-situ resource utilization. Given years of time required for acquiring a new rocket engine, a national-level R&D program to develop a methane engine is highly desirable at the earliest opportunity in order to catch up with this worldwide trend towards reusing launch vehicles for competitiveness and mission flexibility. In light of the monumental cost associated with development, fabrication, and testing of a booster stage engine, it is strategically a prudent choice to start with a low-thrust engine and build up space application cases.
https://doi.org/10.6108/KSPE.2021.25.2.119 인용 PDF KSCI

Sim, Hyung-Seok;Choi, Kyu-Sung;Ko, Jeong-Hwan;Chung, Eui-Seung
- Journal of the Korean Society for Aeronautical & Space Sciences
- /
- v.43 no.2
- /
- pp.156-165
- /
- 2015
A survivability-analysis program has been developed to analyze the ground collision risk of atmospheric reentry objects, such the upper stages of a launch vehicle or satellites, which move at or near the orbital velocity. The aero-thermodynamic load during the free fall, the temperature variation due to thermal load, and the phase shift after reaching the melting point are integrated into the 3 degree-of-freedom trajectory simulation of the reentry objects to analyze the size and weight of its debris impacting the ground. The analysis results of the present method for simple-shaped objects are compared with the data predicted by similar codes developed by NASA and ESA. Also, the analysis for actual reentry orbital objects has been performed, of which results are compared with the measurement data.
https://doi.org/10.5139/JKSAS.2015.43.2.156 인용 PDF KSCI

Kim, Cheulwoong;Lim, Byoungjik;Lee, Junseong;Seo, Daeban;Lim, Seokhee;Lee, Keum-Oh;Lee, Keejoo;Park, Jaesung
- Journal of the Korean Society of Propulsion Engineers
- /
- v.26 no.4
- /
- pp.54-63
- /
- 2022
A 3-tonf class liquid rocket engine that powers the upper stage of a small launcher and lifts 500 kg payload to 500 km SSO is designed. The small launcher is to utilize the flight-proven technology of the 75-tonf class engine for the first stage. A combination of liquid oxygen and liquid methane has been selected as their cryogenic states can provide an extra boost in specific impulse as well as enable a weight saving via the common dome arrangement. An expander cycle is chosen among others as the low-pressure operation makes it robust and reliable while a specific impulse of over 360 seconds is achievable with the nozzle extension ratio of 120. Key components such as combustion chamber and turbopump are designed for additive manufacturing to a target cost. The engine system provides an evaporated methane for the autogenous pressurization system and the reaction control of the stage. This upper stage propulsion system can be extended to various missions including deep space exploration.
https://doi.org/10.6108/KSPE.2022.26.4.054 인용 PDF KSCI

Song, Eun-Jung;Choi, Jiyoung;Cho, Sang-bum;Sun, Byung-Chan
- Journal of the Korean Society for Aeronautical & Space Sciences
- /
- v.45 no.5
- /
- pp.386-392
- /
- 2017
This paper considers the analysis of the flight performance reserve, which is required propellant to compensate various launch vehicle performance deviations, to inject the payload of a 3-staged launch vehicle to a circular sun synchronous orbit at a height of 700 km. The various error sources, which affect the orbit injection accuracy, and their uncertainty are defined first. Then the sensitivity analysis, which has the advantage that each error source effect can be investigated independently, is performed for the extreme ${\pm}3{\sigma}$ conditions of the launch vehicle performance errors. Monte carlo simulations are also conducted to compute the propellant reserve, which can consider the combined effects of each error source. Finally the obtained flight performance reserves by the two approaches are compared and it is confirmed that they show similar results.
https://doi.org/10.5139/JKSAS.2017.45.5.386 인용 PDF KSCI