• Journal of Institute of Control, Robotics and Systems
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• v.15 no.6
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• pp.567-572
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• 2009

The underwater launch system using an ATP consists of five parts: compressor tank, proportional flow control servo valve, expulsion spool valve, air turbine pump, and discharge tube. The purpose of this study is to develop an underwater launch system using an ATP and to verify the validity of the system. The proportional flow control servo valve is modeled as a 2nd order transfer function. The projectile is ejected by pressurized water through the air turbine pump, which is controlled by expulsion valve. The mathematical model is derived to estimate the dynamic characteristics of the system, and the important design parameters are derived by using simulations. The computer simulation results show the dynamic characteristics and the possibility of control for underwater launch system.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.519-527
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• 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 Advanced Navigation Technology
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• v.25 no.4
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• pp.267-272
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• 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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.3
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• pp.72-78
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• 2003

In this paper, the feasibility study and the parametric design of hybrid motor with HTPB/LOX were conducted for micro air launch system. Design results were compared with 1st stage of Pegasus XL for verification of hybrid motor. Results showed that hybrid motor replace solid booster if Isp of hybrid motor reaches 330sec. In addition, mission analysis was established for micro air launch system, and parametric design was conducted with design variables: number of port, initial oxidizer flux, and chamber pressure. And the region of Isp was identified by parametric study which satisfied design constraints and mission analysis.

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

• Advances in aircraft and spacecraft science
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• v.9 no.1
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• pp.1-15
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• 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 the Korea Institute of Military Science and Technology
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• v.23 no.2
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• pp.176-184
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• 2020

In this paper, we have proposed hardware and software architecture of a launch control unit for the compatibility between air defense weapon systems loaded on shipboard. Until now, there is no compatibility between weapon systems loaded in battleships of korean navy. In the case of HaeGung system recently completed the test and evaluations, although it will be deployed on several kinds of shipboards, it has no compatibility and flexibility with other air defense weapon systems. Recently it reports that a long range air defense weapon system will be carried on future korean destroyer KDDX. Because the HaeGung and a long range air defense system will be operated together in KDDX, it is necessary to provide the compatibility between two weapon systems. So we have proposed architecture to provide the compatibility of the launch control unit that controls the launching system and the missile interface unit, and the missile in each weapon systems.

• Aerospace Engineering and Technology
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• v.4 no.2
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• pp.126-134
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• 2005

Before the launch, launch vehicle is set up a few days ago at launch pad to check process and to supply fuels, etc. During the prelaunch process, the payload is exposed to the thermal environments. The purpose of a prelaunch thermal analysis is to predict maximum/minimum liftoff temperature of payload fairing and to evaluate air conditioning performance. The prelaunch thermal analysis of Delta II PLF is performed using Sinda/fluint, general thermal/fluid analyzer. The results are analyzed and compared with Delta II report.

• Journal of Aerospace System Engineering
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• v.16 no.4
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• pp.28-34
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• 2022

In 2021, Virgin Orbit converted a 747-400 aircraft into an air launch platform, and successfully launched it twice in February and July. Compared to the existing ground launch, interest in the air launch is increasing due to its great utility, such as its independence from the launch location or weather, cost reducing factor, shorter launch preparation time, and its benefit pursuant to altitude and speed. Additionally, as small satellites have similar performance to mid/large satellites in the past due to the miniaturization and precision of electronic equipment, small satellite launches are expected to dominate in the future. In this paper, institutional certification methods such as domestic, overseas, civilian and military airworthiness certification regulations/procedures are reviewed to ensure flight safety of aerial projectiles using large domestic civil aircraft, and applicable civil and military airworthiness certification technology standards are reviewed and analyzed. Additionally, we will review and suggest effective airworthiness certification application plans that reflect the reality, and present airworthiness certification standards (draft) for aerial launch vehicles, by analyzing applicable airworthiness certification technical standards when remodeling aerial launch vehicles.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.269-273
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• 2005

The on-board system for the air supply to the payload fairing(PLF) of a launch vehicle using both high and low pressure air was designed. The design concept was obtained from the CFD analysis of a Russian interstage air supply system, and a collector was adopted to expand the high pressure air. To verify that the on-board system would work as designed, a simplified axisymmetric computational model was made and a CFD analysis was also performed. It was found that the flow ejected from the hole of the collector expands to the Mach number of 4 and is soon retarded due to the action of viscosity. It was also found that a small gap between the low pressure duct and equipment bay wall can cause large velocity in PLF over the velocity requirement and no gap should be allowed in the design.