• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.8
• /
• pp.686-694
• /
• 2016

During the Cold War, all space developments were focused on the performance only. However economy becomes more important for space development after the Cold War. There is a growing interest in reusable launch vehicle to secure the economic feasibility. In this paper, technology development prospects and direction of reusable launch vehicles and future propulsion systems of various countries are presented.

• Journal of Astronomy and Space Sciences
• /
• v.1 no.1
• /
• pp.35-39
• /
• 1984

The design of the reusable thermal protection system for the space shuttle orbiter using silica tile played one of key roles in the successful flight of the Columbia and subsequent space shuttles. The basic design goals for this thermal protection system were identified. Manufacturing procedures for the silica tile and the structure of the tile system were also described.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.2
• /
• pp.57.4-57.4
• /
• 2019

BITSE is a project of balloon-borne experiments for a next-generation solar coronagraph developed by a collaboration with KASI and NASA. The coronagraph is built to observe the linearly polarized brightness of solar corona with a polarization camera, a filter wheel, and an aperture door. For the observation, the coronagraph is supported by the power distribution unit (PDU), a pointing system WASP (Wallops Arc-Second Pointer), telemetry & telecommand system SIP (Support Instrument Package) which are developed at NASA's Goddard Space Flight Center, Wallops Flight Facility, and Columbia Scientific Balloon Facility. The BITSE Command and Data Handling (C&DH) system used a cost-off-the-shelf electronics to process all data sent and received by the coronagraph, including the support system operation by RS232/422, USB3, Ethernet, and digital and analog signals. The flight software is developed using the core Flight System (cFS) which is a reusable software framework and set of reusable software applications which take advantage of a rich heritage of successful space mission of NASA. The flight software can process encoding and decoding data, control the subsystems, and provide observation autonomy. We developed a python-based testing framework to improve software reliability. The flight software development is one of the crucial contributions of KASI and an important milestone for the next project which is developing a solar coronagraph to be installed at International Space Station.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.2
• /
• pp.85.1-85.1
• /
• 2017

We develop a coronagraph to measure the coronal electron density, temperature, and speed by observing the linearly polarized brightness of solar corona with 4 different wavelengths. Through the total solar eclipse on 21 August 2017, we test an operating software of a prototype coronagraph working with two sub-systems of two motorized filter wheels and a CCD camera that are controlled by a portable embedded computer. A Core Flight System (CFS) is a reusable software framework and set of reusable software applications which take advantage of a rich heritage of successful space mission of NASA. We use the CFS software framework to develop the operating software that can control the two sub-systems asynchronously in an observation scenario and communicate with a remote computer about commands, housekeeping data through Ethernet. The software works successfully and obtains about 160 images of 12 filter sets (4 bandpass filters and 3 polarization angles) during the total phase of the total solar eclipse. For the future, we can improve the software reliability by testing the software with a sufficient number of test cases using a testing framework COSMOS. The software will be integrated into the coronagraph for balloon-borne experiments in 2019.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.25 no.5
• /
• pp.53-64
• /
• 2021

SpaceX has lowered rocket launch cost innovatively and put first stage reuse to the practical use with Falcon 9. Now the company is developing Starship system that is fully reusable with the heaviest payload in the world. So the system can lower the cost much more and fulfull more diverse mission. For the system the company have developed Raptor engine which is a full-flow staged combustion cycle one with methane fuel. And for the full reusability the company is manufacturing and testing the system prototypes with the barely used technologies such as stainless steel tank, belly flop and retropropulsion during descent. In this study the specification, missions and design features of the system are investigated. Also the development processes of Raptor engine and initial 13 Starship prototypes, which have been manufactured very rapidly, are presented.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.25 no.2
• /
• pp.23-29
• /
• 2019

The volume of parcel delivery is steadily increasing with the rapid growth of the global online e-commerce market. However, a large amount of packaging materials used for these parcel delivery is finally causing environmental problems as waste. The rapid increase of these packaging waste has been making many countries to research ways to reduce the generation of distribution packaging waste. In this study, we have measured the empty space ratio for 131 packagings of parcel delivery purchased through the several domestic online stores in order to investigate the present situation in connection with the degree of excessive or overpack in korean parcel delivery packagings, so that 64 packagings were exceeded 50% in the empty space ratio. And we have suggested ways to reduce the generation of distribution packaging waste raised by e-commerce-based parcel delivery through analyzing the previous research and case studies ; one is to optimize and minimize the packaging design by safe transit test(field-to-lab test), another is to develop a reusable & returnable transport packaging and system applicable in the domestic supply chain, the other is to regulate directly with a policy.

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.1023-1026
• /
• 2005

In the ubiquitous computing environment, an intelligent vehicle is defined as a sensor node with a capability of intelligence and communication in a wire and wireless network space. To make it real, a lot of problems should be addressed in the aspect of vehicle mobility, in-vehicle communication, common service platform and the connection of heterogeneous networks to provide a driver with several intelligent information services beyond the time and space. In this paper, we present an intelligent information system for managing in-vehicle sensor network and a vehicle gateway for connecting the external networks. The in-vehicle sensor network connected with several sensor nodes is used to collect sensor data and control the vehicle based on CAN protocol. Each sensor node is equipped with a reusable modular node architecture, which contains a common CAN stack, a message manager and an event handler. The vehicle gateway makes vehicle control and diagnosis from a remote host possible by connecting the in-vehicle sensor network with an external network. Specifically, it gives an access to the external mobile communication network such as CDMA. Some experiments was made to find out how long it takes to communicate between a vehicle's intelligent information system and an external server in the various environment. The results show that the average response time amounts to 776ms at fixed place, 707ms at rural area and 910ms at urban area.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.11
• /
• pp.997-1005
• /
• 2016

Flight software plays an important role in operating satellites, such as processing commands from ground station, controlling satellites and processing mission data. Reliability is the most important thing in flight software and many verifications and tests are needed for assuring it. this causes an increase of cost and period of development. So NASA has developed a reusable flight software platform to apply to their satellite projects. The CFS(Core Flight System) is the very result. We are developing our flight software for a nano-satellite based on NASA CFS. We have tested core services and functions provided in CFS and we have designed and implemented flight software based on these.

• Advances in aircraft and spacecraft science
• /
• v.9 no.1
• /
• pp.59-68
• /
• 2022

The physical and mathematical foundations of the heat-shielding composite materials functioning under the conditions of aerodynamic heating of aircraft, as well as under the conditions of the point effect of high-energy radiation are considered. The problem of deformation of a thin shallow shell under the action of a local temperature field is approximately solved. Such problems arise, for example, in the case of local destruction of heat-protective coatings of aircraft shells. Then the aerodynamic heating acts directly on the load-bearing shell of the structure. Its destruction inevitably leads to the death of the entire aircraft. A methodology has been developed for the numerical solution of the entire complex problem on the basis of economical absolutely stable numerical methods. Multiple results of numerical simulation of the thermal state of the locally heated shallow shell under conditions of its thermal destruction at high temperatures have been obtained.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.5
• /
• pp.711-720
• /
• 1995

This paper describes in object-oriented retrieval framework that is generally designed to store and retrieve the reusable components from the library regardless of the underlying representation of the library. We propose a retrieval framework on visual space so that reuser can identify their location at the library without any previous information of library structure. They can decide the directions of retrieval with the results displayed on the visual space and interact with the library using the defined simple retrieval operation that can assess the library information object. For doing this, 4I model was proposed. Librarian as well as reuser can easily construct the new library on the visual environment. It is the process to give the semantic of the information object. This paper discusses the basic concepts of our 4I model and explains each constituent of our model and shows a simple example of the system.