• Title/Summary/Keyword: Rendezvous

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Mission Analysis of Space Vehicle (우주비행체의 임무해석)

  • 박수홍
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2001.11a
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    • pp.125-129
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    • 2001
  • A Software development of space launch vehicle danamics and control simulation is presented in this study. The Dynamics for a two body problem including pertubations for various effect show on this paper. Mission analysis for space launch vehicle is included rendezvous mission. The software develpoment is intended to maintain generality to the extent possible through objected approach for future modification and expansion. This result shows various pertubation effect is also important.

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A Rendezvous Node Selection Scheme Considering a Drone's Trajectory for Reliable Data Collection (안정적인 데이터 수집을 위해 드론의 비행경로를 고려한 랑데부 노드 선정 기법)

  • Min, Hong;Jung, Jinman;Kim, Bongjae;Heo, Junyoung
    • KIISE Transactions on Computing Practices
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    • v.24 no.2
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    • pp.77-81
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    • 2018
  • Many studies that improve the efficiency of data collection and a network's lifetime by using a mobile sink have been conducted using wireless sensor networks. If a drone is used as a mobile sink, the drone can collect data more efficiently than can existing mobile sinks operating on the ground because the drone can minimize the effects of obstacles and the terrain. In this paper, we propose a rendezvous node selection scheme which considers estimated drone's trajectory and data collection latency of sensor networks for reliable data collection, when a drone whose trajectory is not predetermined works with terrestrial wireless sensor networks. A selected rendezvous node on the ground collects data from the entire network and it sends then collected data to the drone via direct communication. We also verify that the proposed scheme is more reliable than previous schemes without considering the drone's trajectory and data collection latency.

Scenario Design for Verification of Rendezvous Docking Technology for Nanosatellite (초소형 위성의 랑데부/도킹 기술 검증을 위한 시나리오 설계)

  • Kim, Kiduck;Kim, Hae-Dong;Cho, Dong-Hyun
    • Journal of Space Technology and Applications
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    • v.2 no.1
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    • pp.30-40
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    • 2022
  • This paper illustrates the trajectory design of drift distance recovery after initial launch and proximity operation when verifying rendezvous/docking technology using nanosatellites. The rendezvous/docking is a technology that is the basis of on-orbit servicing technology and is a preemptive process essential for approaching a target object. In particular, since it is difficult to verify in space, nanosatellites have recently been used to reduce the risk and cost of the development stage. Therefore, this paper not only introduces the configuration and specifications of thrusters for nanosatellites but also designs relative trajectories that can take into account the thrust limitations which come from the small size and low power of nanosatellites. In addition, we intend to be helpful in later designing scenarios according to the improvement of available thruster performance through comparison of trajectories and thrust usage with cases without thrust limitations.

Ground Test of Docking Phase for Nanosatellite (초소형위성 지상 환경 도킹 시험)

  • Kim, Hae-Dong;Choi, Won-Sub;Kim, Min-Ki;Kim, Jin-Hyung;Kim, KiDuck;Kim, Ji-Seok;Cho, Dong-Hyun
    • Journal of Space Technology and Applications
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    • v.1 no.1
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    • pp.7-22
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    • 2021
  • In this paper, we describe the results of the docking phase test in the ground environment of the rendezvous/docking technology verification satellite under development for the first time in Korea. rendezvous/docking technology is a high-level technology in space technology, which is also very important for accessing and performing tasks on relative objects in space orbit. In this paper, we describe the ground test results that the chaser finally docks the fixed target using an air bearing device. Based on the thrust control algorithm in the docking phase and the relative object recognition and relative distance estimation algorithm using visual-based sensors validated in this paper, we intend to use them for later expansion to rendezvous/docking algorithms in three-dimensional space for testing in space.

THE EFFECT OF AIR DRAG IN OPTIMAL POWER-LIMITED RENDEZVOUS BETWEEN COPLANAR LOW-EARTH ORBITS (유한 전력 추력기를 사용하는 우주비행체의 동일 평면상에서의 랑데뷰시 공기저항의 영향)

  • 맹길영;최규홍
    • Journal of Astronomy and Space Sciences
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    • v.15 no.1
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    • pp.221-228
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    • 1998
  • The effect of air drag was researched when a low-earth orbit spacecraft using power-limited thruster rendezvoused another low-earth orbit spacecraft. The air density was assumed to decrease exponentially. The radius of parking orbit was 6655.935km and that of target orbit was 7321.529km. From the trajectories of active vehicles, the fuelconsumption and the magnitude of thrust acceleration, we could conclude that the effect of air drag had to be considered in fuel optimal rendezvous problem between low-earth orbit spacecrafts. In multiple-revolution rendezvous case, the air drag was more effective.

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Dynamic DNS design for HIP (HIP을 적용한 동적 DNS 설계)

  • Jung-Soo Park;In-June Jo
    • The Journal of Engineering Research
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    • v.6 no.2
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    • pp.125-130
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    • 2004
  • In the current Internet, IP addresses does not support Mobility and Multi-homming because it depend on their topological location. To resolve these problems, IETF hip WG introduces Host Identity Protocol that separates the endpoint identifier and locator roles of IP addresses. However the DNS that was presented for the HIP had only a part of the expansion design from the existing DNS function, so it was not an absolute complete method. This paper propose how the dymanic DNS has been designed so that it support the HIP completely. We added the Host Identity Namespace and the Rendezvous Server Namespace, defined the new PRs in DNS.

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Retrieval of a dislodged and dismounted coronary stent; using a rendezvous and snare technique at the brachial artery level via femoral approach

  • Jeong, Min-Woong;Sohn, Chang-Bae;Kim, Su Hong;Park, Jong-Ik;Park, Se-Ryeong;Min, Jun-Sik
    • Journal of Yeungnam Medical Science
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    • v.33 no.2
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    • pp.138-141
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    • 2016
  • Coronary stent dislodgement during percutaneous coronary intervention, which occurs when the stent is passed through tortuous and calcified lesions, is not a rare complication. Without proper treatment, such as fixing with another stent in the coronary artery or removing the undeployed stent from the coronary artery or systemic artery system, this complication can cause serious problems. We experienced the unusual situation of a dismounted and dislodged coronary stent, in which retrograde retrieval to the radial artery was impossible during transradial coronary intervention. We report on use of a rendezvous and snare technique at the brachial artery level via femoral puncture, which resulted in resolution without surgery.

A QoS of Delay supporting Scheme for IP Multicast Routing (인터넷 멀티캐스트 라우팅에서 지연시간에 대한 QoS를 지원하는 방법)

  • Park, Se-Hun;Ahn, Sang-Hyun
    • Journal of KIISE:Information Networking
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    • v.28 no.4
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    • pp.498-507
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    • 2001
  • For the Internet multicast routing, there are some protocols researched. This paper presents a new protocol called DPIM (Delay-bounded PIM) to support QoS of delay in multicast routing. This protocol is based on PIM-SM. When the specified delay bound is not satisfied by dynamic membership, the RP (Rendezvous Point) of shared tree is changed and the shared tree is reconstructed. Therefore, the QoS of delay is always supported in this protocol. Through performance analysis and comparison with other protocol, we certify that this protocol is pertinent.

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