Untitled

Rocket

로켓에는 크게 위성발사체와 미사일이 있습니다. 이 둘의 분류는 각 로켓이 탑재하는 있는 것이 무엇이냐에 따라 나눈 것입니다. 인공위성을 싣고 있으면 발사체 (Launch Vehicle)라고 하고 살상용 무기를 싣고 있다면 미사일이 되는 것이죠.
발사체란 인공위성을 궤도로 올려 놓기 위한 것입니다. 작은 인공위성의 몸체에는 지구의 중력을 이기고 대기권을 벗어날 힘이 없습니다. 그래서 자신보다 훨씬 큰 발사체에 몸을 맡기고 갑니다.
그 다음에 지구 중력권을 충분히 벗어나면 발사체에서 인공위성이 분리되 원래의 계획했던 궤도로 찾아들어가게 됩니다. 물론 인공위성에도 작은 추력기가 달려있습니다.

1. 로켓의 작동원리

- 로켓은 비행하는데 필요한 힘을 연료과 산화제의 연소작용에 의해서 발생된 연소가스를 엔진의 노즐 밖으로 보냄으로써 얻습니다.
가스를 밖으로 보내면 뉴튼의 3법칙 작용-반작용법칙 또는 운동량 보존의 법칙에 의해서 그 가스가 가진 운동량만큼 로켓이 추진력을 얻게 됩니다.

2. 로켓의 종류

(1) 열 로켓 (Thermal Rocket) - 추진제에 따라 분류

    - 화학로켓(고체로켓, 액체로켓, 하이브리드로켓 -> 추진제가 고체냐 액체냐에 따라서)
    - 태양풍 추진로켓 (solar sail)
    - 레이저 로켓 (Laser Rocket)

(2) 전기로켓 (Electric Rocket)

    - 전열 로켓 (전기저항제트, 아크제트)
    - 정전기 로켓 (이온엔진, 콜로이드)
    - 전자기 로켓 (Stationary Plasma Thruster, MHD 등)

(3)원자력 로켓 (Nuclear Rocket)

3. 로켓의 추력

- 추력이란 로켓 또는 우주비행체를 추진하는 힘으로 고속의 배기가스를 생성하기 위해서 고온 고압의 연소가스가 필요한데,이는 보다 많은 에너지를 함유하는 연료와 가능한 한 낮은 분자량을 갖는 배기가스를 가짐으로써 가능하다.

- 추력 방정식
F = dm/dt * V + (Pe-Pa)*A

- 로켓의 비추력 이란..
단위 추진제 유량당 생성할 수 있는 추력으로 정의하고 값이 높을수록 원하는 추력을 얻을 때 낮은 추진제가 필요하므로 대부분 높을 수록 좋음,,

4. 발사체의 종류

  (1) 로켓의 재생여부
      - 재생 발사체 (Reusable Lauch Vehicles(약자로 L/V)) : Space Transportation System
      - 소모성 발사체 (Expendable L/V) : 대부분의 발사체

  (2) 궤도에 따른 분류
     - 정지궤도용 (GEO, GSO)
     - 저궤도용 (LEO)

  (3) 발사 탑재능력에 따른 분류
     - 초대형(Heavy Lift L/V : HLLV) - Arian 5, Proton D1e/D1, Delta III, Delta IV, Zenit, STS, Sea Lauch
     - 대형 (Large L/V ; LLV) - Arian 44L, Atlas IIAS, Long March 3A/2E, H-IIA, GSLV
     - 중형 (Medium L/V ; MLV) - Delta II 6925/7925, Athena-3, Long March 3, PSLV, Tsyclon, Molniya
     - 소형 (Small L/V ; SLV) - ASLV, SLV-3, Taurus, Scout, Cosmos, Rocket, Athena-1&2, Pegasus-XL

(4) 유명 발사체의 개관 ---->> 최근 발사체 자료(정말마나요) Click

Name: Atlas II (Atlas I, Atlas IIA, Atlas IIAS)
발사하는 나라/기관: U.S.A / National Aeronautics and Space Administration(NASA)
만든회사: U.S. Air Force (USAF)
운영: U.S. Air Force (USAF)/Lockeed Martin Corp./International Launch Service (ILS)
발사장:Cape Canaveral Air Force Base,Tyuratam Launch Center (Baikonur Cosmodrome)
처음발사한때:
Atlas I: July 25, 1990 to 1999
Atlas II: December 7 , 1991
Atlas IIA: June 10, 1992
Atlas IIAS: December 15, 1993 to 1996
아틀라스 발사체는 처음에 미국에서 대륙간 탄도 미사일로써 개발되었고 최초의 실험발사가 1957년 12월에 있었다. 비록 이 발사체가 핵탄두를 장착하고 1961년에 실전에 배치되었다고 해도 이것은 항상 사용가능하지는 않았다. 왜냐하면 이것은 발사하는데 액체산소를 사용했고 1965년 타이탄II 에 의해서 교체되었기 때문이다.
Among these missiles, the new versions of the E and F were converted into satellite launch vehicles. Many Atlas/Agenas and Atlas/Centaurs, vehicles equipped with Agenas and Centaurs on the upper stage, were produced by the USAF as well as by NASA. Especially the Atlas/Centaurs were used in a broad range of activities along with the Delta and the Titan, as the leading launch vehicle, in spite of troubles with manufacturer's mergers and takeovers.

Atlas I 과tAtlas II (IIA, IIAS) 는 아틀라스의 민간회사들의 상용목적으로 사용된 아틀라스의 마지막 시리즈이다.

The Atlas I is a commercial version of Atlas/Centaur rocket which has mainly been used to launch satellites and deep space probes by NASA. 18 vehicles of this version were planned to be produced, but production was stopped at the 11th vehicle and the Atlas I was converted to the Atlas II which was employed by the USAF. Atlas I is produced by the Lockheed Martin Co. and is used for the satellite launch business by the International Launch Service (ILS) which has launch platforms in Baikonur, Russia as well as in Cape Canaveral.

Atlas II 의 다른 버전인 the Atlas/Centaur, USAF의 발사체로서의 요구에 따라서 USAF와 ILS에서 만들었다.

Name: Delta II
발사하는 나라/기관:United States of America/National Aeronautics and Space Administration (NASA)
만든회사: The McDonnell Douglas Space Systems Co.
운영:The United States Air Force (USAF),National Aeronautics and Space Administration (NASA)
발사장:Cape Canaveral Air Force Base
처음발사한때:Feb 14, 1989 (6900 series)/Nov 26. 1990 (7900 series)
Description:The Delta II is the latest model of the Delta series whose first vehicle was launched in 1960. This version was developed in 1987 in order to make up for the accident of the Challenger in 1986 and to recover the launching ability of the US Air Force. The Delta II is a three stage rocket like previous Delta models, with nine solid rockets strapped around the first stage.

The first model, the 6925 series, was used to launch the U.S. Air Force Navstar GPS satellite in 1989. In 1990, the up-graded 7925 appeared, using a new fuselage material, which changed from steel to a carbon/epoxy material and an improved main engine on the first stage.

The Delta II has a middle class launching capacity, which enables it to place about a 5 ton satellite at an orbit angle of 28 degrees, as well as about a 3.8 ton satellite at an orbit angle of 90 degrees into a low earth orbit at an altitude of 160km, and about a 900kg satellite into geostationary orbit at an altitude of 35,200km.

Name: Titan(Titan I, Titan II, Titan III, Titan IIIA, Titan IIIC, Titan IV)
발사하는 나라/기관: U.S. Air Force (USAF), National Aeronautics and Space Administration (NASA)
만든회사: U.S. Air Force(USAF)/Martin (Rocket Engine is developed by Aerojet)
처음발사한때: 1951 (Titan I, the experiment with the first stage engine),1962 (Titan II)
The Titan rocket was developed by the USAF as an ICBM (intercontinental ballistic missile), at the end of the 1950's when the U.S.A. and the Soviet Union were respectively proceeding to station their nuclear weapons. The Titan I was also planned to be used for the Dyna Soar program which was the basis of the Space shuttle program, but was converted to the Titan IIIC due to its limited capacity. Furthermore the Dyna Soar program itself was also abandoned. The Titan II was a two stage vehicle and was used for the Gemini program as well as the ICBM.

More than 140 missiles of the Titan II were produced, but since 1988, some of them have been modified to be reused as launch vehicles, because the outlook for nuclear war was eliminated in 1987.

The Titan III has various versions such as the Titan IIIA, a two stage rocket with a special transtage, the Titan IIIB, Titan IIIC with a solid propellant booster on the first stage, the Titan IIID which removed the transtage from IIIC, the Titan IIIE with the Centaur replaced by the original third stage, and the Titan IV, developed by the USAF for a large sized satellite launch after the accident of the Challenger, which has become the indispensable vehicle for launching satellites and space probes.

Name: X-33
Launch country/organization: United States of America/National Aeronautics and Space Administration (NASA)
만든회사: National Aeronautics and Space Administration (NASA)
운영: National Aeronautics and Space Administration (NASA)
발사장: Edwards Air Force Base
Description: The X-33 is designed to follow the space shuttle as a manned re-usable Launch Vehicle (RLV). The RLV plan aims to reduce the cost of sending payloads into space to about $1,000 per pound. To do so requires eliminating expendable parts in a system currently under development and known as the Single Stage to Orbit (SSTO). The X-33 will not have the ability to launch a satellite, but if its experiments go well, the next step will be to create a large SSTO craft capable of doing so. Three companies submitted plans for the X-33 -- McDonnell Douglas, Rockwell International and Lockheed Martin. In July 1996, the project contract was awarded to Lockheed Martin. Lockheed Martin plan to use a linear aerospike nozzle in its rocket engine and replace the space shuttle's ceramic tiles with a heat resistant metallic surface. The first test flight of the X-33 is due in March 1999 and will take off from Edwards Air Force Base in California, flying as high as 70 kilometers into the sky. If the tests can be completed soon enough, X-33 will be ready for use by the end of 1999. Lockheed Martin are also working on the Venture Star, a different version of the X-33, which appears likely to be held back for use until around 2003 or 2004.

Name: Ariane IV/Ariane 4
발사하는 나라/기관: European Union/European Space Agency
만든회사:European Space Agency
운영:Arianespace
발사장: Guiana Space Center(GSC)
처음발사한때: January 29, 1984
The Ariane IV is the latest version followed by the Ariane I that lifted off on December 24, 1979, and the Ariane II and III in 1984. The Ariane IV is an upgraded version of the Ariane I like the Ariane II and III, while the Ariane V, which has the future title role in Europe, is designed completely different lines.

The payload placed in geostationary transfer orbit increased almost three-fold, from 1.8 to 4.8 tons compared to the capacity of Ariane I, by reinforcing each stage, especially the first stage and employing an auxiliary booster.

Over 90 vehicles of the Ariane series lifted off by the autumn

Although the capacity of the Ariane IV is smaller than that of the Ariane V, which is able to transfer a 7 ton satellite into geostationary transfer orbit.

Name: Ariane V/Ariane 5
발사하는 나라/기관: European Union/ European Space Agency
만든회사:European Space Agency
운영:Arianespace
발사장: Guiana Space Center(GSC)
처음발사한때: June 4, 1996
The Ariane V is able to carry a payload of 19 - 20.5 tons into low earth orbit as well as a payload of 7 tons in geostationary transfer orbit. It was developed as the leading European vehicle to compete with China and Japan.

This vehicle was also being considered to be used for the Hermes program to develop the reusable vehicle with wings - the European Union version of the space shuttle - (the Hermes programs was canceled afterwards). It was designed for a manned spacecraft mission, but as of now, has not been realized through European ability.

However, the first vehicle equipped with the scientific satellite, "Cluster" exploded just after liftoff because of control failure and the mission failed on June 4 , 1996.

But investigation revealed that this accident was caused by trouble with the control software and not by the vehicle itself.

On 30 October 1997, the second vehicle was launched and placed MASQSAT-H on orbit at the altitude of 27000 kilometers.

Though the altitude was lower than expected one (30000 kilometers) because of something wrong in its second stage combution, ESA published that the launch itself was successful.

The 3rd test vehicle was successfully launched in the autumn of 1998, and commercial launches will be started after the 4th vehicle.

Name: H-II
발사하는 나라/기관: Japan/National Space Development Agency of Japan(NASDA)
만든회사: National Space Development Agency of Japan(NASDA)
운영:National Space Development Agency of Japan(NASDA)
발사장: Tanegashima Space Center(TNSC)
처음발사한때: 1994
Description: The H-II is a two stage rocket which is able to launch a two ton class satellite into geostationary orbit, equipped with two large sized solid rocket boosters (SRB). This vehicle was developed in 1982, and was launched for the first time in 1994.

The first stage carries the LE-7 liquid hydrogen/liquid oxygen engine.
The second stage carries the LE-5A engine which is an improved model of the LE-5.

The H-II has a flexible launching ability that enables it to launch: two ton class satellites into geostationary orbit, two one ton class satellites simultaneously into geostationary orbit, ten ton class satellites into low earth orbit and two ton class probes to planets like Mars and Venus.

H-II employs the ring laser gyro guidance system (gyroscope using laser beams) and a strapped-down inertial guidance system, (using inertial guidance computers) to continuously calculate the flight position and rocket speed. With these systems, the rocket is able to fly on the objective orbit correcting the differences by itself.

Name: H-IIA
발사하는 나라/기관: Japan/National Space Development Agency of Japan(NASDA) 일본항공우주국
만든회사: National Space Development Agency of Japan(NASDA)
운영: National Space Development Agency of Japan(NASDA)
발사장: Tanegashima Space Center(TNSC)
처음발사한때: Mission Planned from 2000
Description: The H-IIA is being developed to meet various demands with high reliability and low cost for missions in the 21st century including launching satellites and transporting supplies to space stations. The H-IIA in its configuration is able to launch a two ton class satellite into geostationary orbit. It also is able to launch a three ton class satellite into geostationary orbit in the configuration augmented by a large liquid rocket booster. Its growth capacity and design potential is to launch up to a four ton class satellite into geostationary orbit. The vehicle for a three ton class will be launched from the Tanegashima Space Center in 2000.

The first stage of the H-IIA carries an LE-7A engine which is an improvment of the LE-7 engine. The improved two solid rocket boosters (SRB-A) which are almost the same size as the first staged liquid rocket, carries two LE-7A engines to use for launching a three ton class satellite.

The second stage carries the LE-5B which is an improved model of the LE-5A. The attitude control of the second stage is performed by the thrust vector control of the LE-5B engine nozzle with an electrical actuation system and a hydrazine gas-jet reaction control system.

H-IIA employs a strapped-down inertial guidance system as H-II does.

Name: Long March (CZ) 4/Chang Zheng (CZ) 4
Launch country/organization: China/China National Space Administration (CNSA)
만든회사: China National Space Administration (CNSA)
운영: China National Space Administration (CNSA)
발사장: Jiuquan Satellite Launch Center,Taiyuan Satellite Launch Center
처음발사한때: 1988
Description: The Chang-Zheng rockets were developed entirely in China and are also known by their English name of Long March (LM). The Long March 4 (CZ-4, LM-4) that appeared in 1988 was developed to orbit around the Sun and observe weather and environmental conditions. The Chinese public corporation responsible for launching the rockets marketed their product worldwide and were able to carry commercial payloads. The rockets are launched from bases in Taiyuan, Shanxi Province.