• Journal of Advanced Navigation Technology
• /
• v.25 no.4
• /
• pp.267-272
• /
• 2021

The end of the ROK-U.S. missile guidelines opened up the possibility of developing space launch vehicles for various platforms based on air and sea. In particular, the air-based space launch vehicle is an essential space power projection capability compared to the ground-based space launch vehicle in consideration of the geographical location of the Korean Peninsula, such as the deployment of various satellite orbits and the timely launch of satellite. In addition, compared to the ground-based launch vehicle, the cost reduction effect is large, and it has the merit of energy gain because it can be launched with the advantage of the aircraft's altitude and speed. Therefore, in this paper, the necessity of air-based space launch vehicle in the strategic environment of the Korean Peninsula is clearly presented, and through technology trend analysis of various air launch vehicle, the three methods are proposed to have the most efficient air-based space launch vehicle capability in the Korean situation.

• Advances in aircraft and spacecraft science
• /
• v.9 no.1
• /
• pp.1-15
• /
• 2022

This paper presents calibration of flush air data sensing systems during ascent period of a satellite launch vehicle. Aerodynamic results are numerically computed by solving three-dimensional time dependent compressible Euler equations over a payload shroud of a satellite launch vehicle. The flush air data system consists of four pressure ports flushed on a blunt-cone section of the payload shroud and connected to on board differential pressure transducers. The inverse algorithm uses calibration charts which are based on computed and measured data. A controlled random search method coupled with neural network technique is employed to estimate pitch and yaw angles from measured transient differential pressure history. The algorithm predicts the flow direction stepwise with the function of flight Mach numbers and can be termed as an online method. Flow direction of the launch vehicle is compared with the reconstructed trajectory data. The estimated values of the flow direction are in good agreement with them.

• Journal of Advanced Navigation Technology
• /
• v.27 no.5
• /
• pp.519-527
• /
• 2023

Air-launch means launching from aircraft such as fighter jets, and has various advantages, such as cost reduction and less environmental/weather impact during launch. However, there are no air-launch satellite in Korea. Examining air-based launch satellite and anti-satellite missiles operated and developed by foreign private companies and various countries confirmed the necessity of domestic research and development. In South Korea, various research activities, including satellite launch system design and development approaches for different launch platforms, have been carried out mainly by academia. Development of upward maneuver air launch technology which is launched in the air when the aircraft is moving upward is suggested. Additionally, an introduction to wind tunnel tests for safety separation verification is provided. A new concept for a test facility has been suggested to conduct drop tests.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.4
• /
• pp.53-60
• /
• 2004

Optimal design of the hybrid motor has been performed for the first stage of nanosat air launch vehicle using F-4E Phantom as mother plane. Selected design variables are number of ports, the initial oxidizer flux, the combustion chamber pressure, and the nozzle expansion ratio. GBM(Gradient Based Method) and GA(Genetic Algorithm) are simultaneously used to compare the versatility of each algorithm for optimal design in this problem. Also, two objective functions of motor weight, and length are treated separatedly in the optimization to study how the objective function can affect the optimal design. The design results show that the optimal design can be successfully achieved either using GBM or GA regardless of the choice of the objective function; motor weight or length. And nanosat air launch vehicle which has total mass of 704.74kg, and length of first stage 3.74m is designed.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.6
• /
• pp.10-18
• /
• 2015

Performance requirement analysis and weight estimation of a reusable launch vehicle with a rocket-based air-breathing engine(RBCC : Rocket Based Combined Cycle) were performed. Performance model for an RBCC engine was developed and integrated with flight trajectory model. The integrated engine-trajectory model was validated by comparing the results with those from previous research reference. Based on the new engine-trajectory model and previous research results, engine performance requirements were derived for an reusable launching vehicle with gross take-off weight of 15 tones. Dependence of the propellant amount requirement on the mode transition Mach number of the engine was also analyzed.

• Aerospace Engineering and Technology
• /
• v.11 no.1
• /
• pp.57-67
• /
• 2012

In this study, design of LCTS(Launch Complex Thermostatting System), which is one of ground support equipments for KSLV-I, is analyzed based on CDP(Critical Design Package) provided by Russia. The thermo-hydraulic design of air preparation compartment and hydraulic design of air heating & distribution compartment performed. Also numerical simulation of air heating & distribution compartment was conducted and compared with actual measurement data. Finally, insulation design of system was analyzed. Designing method of LCTS will be helpful in developing or modifying LCTS for new launch vehicle.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.16 no.1
• /
• pp.16-24
• /
• 2012

In this study, two-stage hypersonic scramjet vehicle was designed for the flight condition of Mach number 6. In order to launch at sea level, two stage concept was applied. The first stage of the vehicle is solid rocket-powered and is mounted under the second stage. The second stage is powered by scramjet propulsion system and gas wings. The suggested mission scenario is to deliver 0.2 ton payload to the range of 2,000 km. For the first step of conceptual design, trajectory of air vehicle was calculated by 3-DOF trajectory code. Based on the result of trajectory code, scramjet engine design and mass estimation were performed by non-equilibrium nozzle flow code and NASA's HASA model, respectively. In order to find best solution, all steps of designing process was iterated until they was reached.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.04a
• /
• pp.309-317
• /
• 2011

In this study, two-stage hypersonic scramjet vehicle was designed for the flight condition of Mach number 6. In order to launch at sea level and Mach number 0, two stage concept was applied. The first stage of the vehicle is rocket-powered and is mounted under the second stage. The second stage is scramjet-powered propulsion system and has wing. The suggested mission scenario is to deliver 0.2 ton payload to the range less of 2000km. For the first step of conceptual design, trajectory of air vehicle was calculated by 3-DOF trajectory code. Based on the result of trajectory code, scramjet engine design and mass estimation were performed by non-equilibrium nozzle flow code and NASA's HASA model, respectively. In order to find best solution, all step of designing process was iterated until they were converged.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.7
• /
• pp.637-646
• /
• 2010

A time-domain panel method based on the potential flow theory and the time-stepping method is developed to predict the steady/unsteady aerodynamic characteristics of FM07, which is the BWB (Blended-wing body) type MAV. In the aerodynamic analyses, we used two types of the initial model(Case I) and the improved model(Case II), which is moved the gravity center toward the rear and has larger aspect ratio. In the steady aerodynamic analyses, it is revealed that improved model has higher lift to drag ratio(L/D) and more stable pitch characteristic than those of the initial model. In the unsteady aerodynamic analyses for sudden acceleration motion similar to the launch phase of MAV, it seemed that there is a rapid increase of the lift coefficient after the launch and unsteady results are good agreed compare with steady results in just a few times. In the analysis for pitch oscillation motion, which is occurred at the cruise condition of the FM07, it shows that unsteady aerodynamic coefficients looped around steady results and the improved model has more sensitive aerodynamic characteristics.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.05a
• /
• pp.7-10
• /
• 2009

The development and evaluation of solid propellant were performed for the turbopump pyro starter, which start up the liquid propellant rocket engine for the Space Launch Vehicle (SLV). Requirements for the turbopump pyro starter propellant include the production of low flame temperature, low burning rate and nontoxic gas to protect the mechanical corrosion or air pollution. This study describes the development of the solid propellant composition which is based on PCP binder. DHG (Dihydroxy glyoxime), which has advantages of oxygen balance and ignition, was used as coolant. The mechanical properties and burning rate of the propellants were measured. Finally, static fired test was performed to prove the possibility of development.