• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.10
• /
• pp.855-862
• /
• 2017

Due to the weight reduction and miniaturization of satellites, there is a growing interest in low-cost launch vehicles, which are cheaper to launch than larger launch vehicles. One of the most cost-effective ways to reduce the cost of launch vehicles is the reuse of vehicles. Most companies that are developing low cost launch vehicles are also adopting a vehicles reuse approach. Along with this reuse purpose, the demand for environmentally friendly space launch vehicles has increased, so the choice of fuel used for low cost launch vehicles has also become very important. Methane and hydrogen-enriched compressed natural gas (HCNG), which makes more energy-efficient by adding hydrogen to methane, are considered to be the most suitable when considering other factors such as energy density among the fuels that are eco-friendly and capable of reusing the launch vehicles. This study investigated the trends of low-cost launch vehicle and rocket fuel in the world as a reference for setting up domestic space development after the development of Korea Space Launch Vehicle-II.

• Journal of Aerospace System Engineering
• /
• v.10 no.4
• /
• pp.59-66
• /
• 2016

India and China are capable of developing indigenous space launch vehicles, with the rocket technology transferred from the U.S., Western countries, and the Soviet Union, in the 1950s and 1960s. Barring the early 1990s, both countries are absent in the missile nonproliferation regime, and have no major space cooperation records with the U.S., since the establishment of the Missile Technology Control Regime in 1987. With the advent of the $21^{st}$ century, historic progress has been made in the U.S.-India space cooperation, which includes using Indian launch vehicles to launch U.S.non-commercial satellites. However, the U.S. is skeptical with regards to space cooperation and using Chinese space launch vehicle services. In this paper, we present the U.S. nonproliferation policy applied on launch vehicles of India and China, and different aspects of the policy will be examined to draw implications on Korean space activities.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.23 no.6
• /
• pp.72-86
• /
• 2019

SpaceX is currently leading the global launch market with the successful launch and recovery of Falcon 9 v1.2 Block 5. SpaceX developed Merlin engine, a kerosene gas generator engine, and continuously upgraded the engine from Falcon 1 to Falcon Heavy to increase payload weight. SpaceX suffered a lot of failures early on, but with the help of NASA, it was possible to overcome many crises and develop vehicles. In addition, it successfully developed reusable vehicles, which drastically reduced operating costs. Subsequent launch vehicles in Korea also need to be developed with reference to SpaceX's development strategy.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.10
• /
• pp.936-942
• /
• 2015

This paper suggests the significant strategies and their priority to deal with space transportation market trends. First, market trends related with technical improvement and change in demand are analyzed by the literature research. The three key trends are obtained: 'Increasing Demand of High-Performance Launch Vehicles', 'Rising of Low-Price Launch Vehicles', and 'Rising of Dual/Multi-Launch'. And then, strategies for developing the launch vehicle industry in Korea are selected from several studies about commercialization of Korean launch vehicle. The strategies are evaluated by the experts through pairwise comparison matrix and the criteria for this process is how significantly does the strategy effect on the launch vehicle industry through market assessment. As a result, reliable order of priority among the strategies are obtained. Under the three key trends, strategy to enhance reliability is most important. And, strategy to have price competitiveness has secondary priority to deal with 'Rising of Low-Price Launch Vehicles' trend and 'Rising of Dual/Multi-Launch' trend. On the contrary, strategy of government's support is secondary under 'Increasing Demand of High-Performance Launch Vehicles' trend.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.24 no.5
• /
• pp.91-102
• /
• 2020

Recently, a new space era has evolved in which commercial companies' led space development has begun. In this era, commercial companies actively participate in space development as the size of the small satellite market and small launch vehicle market is expanding. Through space development, developed countries are making efforts to reduce development, production, and operation costs to secure the competitiveness of small launch vehicles. In this study, the development trend of small launch vehicles and required technologies for space development were analyzed and summarized. Thus, research and development is urgently needed so that spin-on technologies, such as electric pumps and additive manufacturing, can be utilized for space development.

• Journal of Applied Reliability
• /
• v.4 no.2
• /
• pp.105-119
• /
• 2004

Reliability program is essential to the development of space systems like launch vehicles and satellites, as they are non-repairable after launch and the failure of a launch vehicle resulted in catastrophic consequences for the mission. Foreign advanced space organizations have developed and implemented their own reliability management programs for launch vehicles from the conceptual design stage to the detail processes for the individual components, procedures and test reports. A study on the launch failures and the reliability analysis methods for one-shot devices contained in this paper will contribute to the reliability improvement for Korean launch vehicle and components.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.7
• /
• pp.525-534
• /
• 2019

Water rocket is a pressurized liquid propellant rocket that shares the same basic principles of space launch vehicles. Water rockets can be used as an engineering educational material for the liquid rocket principles and the launch vehicle systems, far beyond the scope of K-12 level science education. In this paper, the principles and theories of water rocket propulsion and flight dynamics was investigated at the level of undergraduate rocket engineering classes. Also, the system level design and operation of water rocket is summarized by including the components of launch vehicle, launch pad, payload and recovery as well as altitude measurement methods.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.23 no.4
• /
• pp.1-9
• /
• 2019

Recently, in the space market, there has been a rapid reduction of the launch price. The major reason is that a few commercial companies, especially SpaceX, began to enter into the space market about ten years ago, which has changed the space market from monopolization to competition, and accelerated the adoption of commercial efficiency in the technology and management. Also, the successful landing and recovery of a first stage in 2016 by SpaceX proved to be a prelude to opening a new era of reusable launch vehicles, and SpaceX declared the groundbreaking launch price through using the reusable launch vehicle. This study calculates the total launch cost required to put a certain satellite into the LEO, compares the launch cost in three cases with different payload weights, and reviews the impacts of the payload on the cost effectiveness of a reusable vehicle. The total launch cost is divided into 6 subsections cost, namely development cost, production cost, refurbishment cost, operation cost, fixed-cost of factory and launch site, and insurance cost. The cost estimation relationships used in the calculation are taken from the commonly proven cost models such as TRANSCOST.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.25 no.3
• /
• pp.101-112
• /
• 2021

SpaceX shows various strategies such as constructing various payload portfolio through the reuse of Falcon 9 and Falcon Heavy, constructing the launch vehicles using one type of engine, the transition from kerosene engine to methane engine, and the use of 3D printing. In this study, launch vehicle proposals that can cover a variety of payloads and trajectories from KOMPSAT to GEO-KOMPSAT were constructed, and ten launch vehicles using kerosene gas generator cycle engine, kerosene staged-combustion cycle engine, and methane staged-combustion cycle engine were reviewed. Of the ten launch vehicles, the reusable launch vehicle using a 35-ton methane engine was rated as the best in terms of development potential.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.393-396
• /
• 2008

Propellant consumption control for space launch vehicle can be achieved by propellant utilization system (PUS) and tank depletion system (TDS). In the course of developing new space launch vehicles, the main target of design is on reducing of space launch vehicle weight, which results in increasing both specific impulse and payload weight. The weights of space launch vehicles are generally allocated to structure, propulsion system, and propellants loaded. The quantity of propellants filled in propellant tanks may be estimated with the propellants actually consumed by propulsion system to complete its mission and the propellants left on-board at the time of engine shut-off. To minimize the remaining quantity of propellants on-board the supplying propellants' O/F ratio should be controlled from the certain time before engine shutdown. To control an O/F ratio, a control system, which accurately measures and compares the remainder of propellants in tanks and pipes, should be needed. This paper solely dedicates its contents to explore the merits and demerits of various level sensor, which is one of the important elements for PUS and TDS, and the transmission and control of signals within space launch vehicle.