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ChangZheng 2 (Long March 2) Launch Vehicle
The ChangZheng 2 (CZ-2, or Long March 2 in its English translation) is the largest space launch vehicle family of the People’s Republic of China (PRC), designed and developed by the China Academy of Space Technology (CALT, also known as CASC 1st Academy). The launch vehicle has been used for both Low Earth Orbit (LEO) or Geostationary Transfer Orbit (GTO) missions. The launcher is available in five variants: CZ-2, CZ-2C, CZ-2D, CZ-2E, and CZ-2F, with two variants currently in development: CZ-2F/G and CZ-2F/H. The ChangZheng 2 design was also used as the core stage for the ChangZheng 3 and ChangZheng 4 launch vehicle families.
ChangZheng 2
The ChangZheng 2 two-stage, liquid-propellant launch vehicle was based on the DongFeng 5 intercontinental ballistic missile (ICBM) introduced in the 1970s. The launcher was developed to send China’s Fanhuishi Shiyan Weixing (FSW) recoverable reconnaissance satellite into the orbit, with a LEO payload of 1,400kg. The development team was led by the Chinese rocket scientist Tu Shou'e.
The first flight of the ChangZheng 2 took place on 5 November 1974, from the Jiuquan Satellite Launch Centre in northwest China. The launcher carried China’s first FSW satellite. Due to a failure of the cable carrying pitch rate gyro signal, the launcher exploded in the midair 20 seconds after launch, destroying the satellite onboard. A second launch was carried out successfully on 26 November 1975, sending the satellite (FSW-0 No.1)into the orbit. This was followed by two subsequent launches in 1976 and 1978, before the launcher was retired and replaced by the improved ChangZheng 2C.
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ChangZheng 2C (Chinese Internet) |
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ChangZheng 2C
The improved ChangZheng 2C was introduced in the early 1980s, with its LEO payload increased to 1,800kg. A total of 26 launches were carried out between 1982 and 2008, with a success rate of 100%. The launch remains in service today. On later variants the LEO payload has increased to 4,000kg.
The first stage of the ChangZheng 2C uses a DaYF6-2 motor consisting of four 75,000kg-thrust YF20 -1 chambers motors with swinging nozzles burning N2O4/UDMH. The second stage has a YF-24F rocket motor consisting of one 75,000kg-thrust YF20-1 main motor with fixed nozzles, and a YF21 swivelling venire motor with four chambers motors that produce a total thrust of 4,800kg.
ChangZheng 2C/SD (Smart Dispenser)
On 28 April 1993, the Chinese Great Wall Industrial Corporation and Motorola signed a launch services contract to launch 12 satellites for the Iridium global wireless communications satellite network. The ChangZheng 2C/SD three-stage launch vehicle was developed specifically for these launch missions. Modifications on the ChangZheng 2C/SD includes a modified 3.35m diameter fairing, improved second stage fuel and oxidizer tanks; and second stage engines with higher expansion ratio nozzles.
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ChangZheng 2C/SM (Chinese Internet) |
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The ChangZheng 2C/SD features a “Smart Dispenser" (SD), a three-axis stabilised upper stage using a solid rocket kick motor for insertion of two Iridium telecommunications satellites into orbit in a single launch. The solid rocket motor consists one 742kN thrust main motor and four 74.1kN swivelling venire motors, with its own onboard guidance system. The SD was developed by the China Academy of Launch Vehicle (CALT), allegedly with assistance of U.S. satellite companies.
Between 1997 and 1999, a total of seven ChangZheng 2C/SD launches were carried out from the Taiyuan Satellite Launch Centre, sending two mock satellites and twelve operational satellites into the orbit.
ChangZheng 2/SM
The ChangZheng 2C/SM features a spin-stabilised solid motor upper stage added on top of the existing CZ-2C core stage. The launch vehicle was used to send the Double Star space scientific research satellites into the orbit. Two launches were carried out between 2003 and 2004.
ChangZheng 2D
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ChangZheng 2D (Chinese Internet) |
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The ChangZheng 2D was developed by Shanghai Academy of Space Flight Technology (SAST, also known as CASC 8th Academy) based on the first and second stages of the CZ-4 space launch vehicle. The CZ-2D is a two-stage, liquid-propellant launch vehicle designed mainly for Low Earth Orbit (LEO) missions, with an LEO payload of 3,700kg. A total of 10 launches were carried out between 1992 and 2008, all from the Jiuquan Satellite Launch Centre.
The CZ-2D is generally carries UDMH/N2O4 for all stages. The first stage uses a YF-21B motor consisting of four 65,000kg-thrust YF-20 chambers motors with swinging nozzles. The second stage has a YF-24F rocket motor consisting of one 75,000kg-thrust YF-22B main motor with fixed nozzles, and a YF-23F swivelling venire motor with four chambers motors that produce a total thrust of 4,700kg. The launcher also features a McDonnell Douglas (now Boeing Aerospace) PAM-D upper stage providing 66,700 lb of thrust.
The ChangZheng 2D is available in two versions: Type A with a 2.90m-diameter fairing and Type B with a 3.35m-diameter fairing.
ChangZheng 2E
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ChangZheng 2E (Chinese Internet) |
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The ChangZheng 2E was a three-stage launch vehicle designed for GTO missions. The launch vehicle was based on the core stage of the ChangZheng 2C, added with four strap-on boosters for additional payload capacity. The launcher is capable of sending 3,500kg payload into the GTO from the Xichang Satellite Launch Centre.
Four 75,500kg-thrust YF5-1 chambers motors with swinging nozzles combine to make the YF6-2 engine that powers the first stage of the core vehicle. The second stage of the core vehicle has a YF20-1 rocket motor consisting of one 75,600kg-thrust main motor with fixed nozzles, a YF21-1 swivelling venire motor with four chambers motors (4,813kg-thrust in total), and larger propellant tanks. The strap-on stages each use a single 75,500kg-thrust YF5-1 engine with a fixed nozzle.
The ChangZheng 2E development began in late 1988 and the launch vehicle was prompted to the international commercial space launch market in 1990. The first launch of the ChangZheng 2E took place on 16 July 1990.Out of the seven launches carried out between March 1992 and December 1995, only four were successful, causing severe damage to China’s space launch business.
Following its last launch in December 1995, the ChangZheng 2E was retired from service. An improved model ChangZheng 2E(A) was proposed by the CALT but the design did not enter production.
ChangZheng 2F
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ChangZheng 2F (Chinese Internet) |
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The ChangZheng 2F was designed by CALT specifically for the PRC’s human spaceflight programme Project 921. The launcher was partially based on the design of CZ-2E, but with a redesigned payload fairing and an emergency escaping system. The reliability of the launcher was also improved in accordance with the requirements of the human spaceflight programme. Development of the launch vehicle began in the early 1990s under the codename “Project 921-4”, and the first launch took place in November 1999.
The ChangZheng 2F has a core stage based on the two-stage ChangZheng 2C, added with four strap-on boosters, each powered by a single 75,500kg-thrust YF5-1 engine with a fixed nozzle. The launch vehicle is capable of sending 8,000kg payload to the LEO. The payload fairing was strengthened in order to accommodate the three-module ShenZhou spacecraft and its escaping system. The second stage of the ChangZheng 2F features enlarged propellant tanks for additional payload capacity.
The launch vehicle is transported in several parts from the manufacture plant to the Jiuquan Satellite Launch Centre by railway. After arriving at the launch centre, the launch vehicle is kept in the LV Horizontal Processing Building for initial examinations and preparations. It is then moved to the LV Vertical Processing Building, where the core vehicle and strap-on boosters are lifted into the vertical position and then assembled together and then integrated with the ShenZhou spacecraft. This whole process normally takes about 5~6 weeks. After further examinations and tests, which normally takes 2~3 days, the launch vehicle together with the spacecraft is then moved in a vertical position on a mobile launch pad to the launch complex. After final checks on the launch pad, the launch vehicle is ready for take-off.
Between November 1999 and September 2008, a total of seven ShenZhou spacecraft launches were carried out using the ChangZheng 2F, including four unmanned missions and three manned missions, with a success rate of 100%. In September 2008, the Chief Designer of the Project 921-4 told the press that the ShenZhou 7 mission was the last flight using the ChangZheng 2F, as the weight of the spacecraft almost reached the maximum of the launch vehicle's payload capacity. Future flight missions in the Project 921 were to be carried out using improved designs.
ChangZheng 2F/G
The ChangZheng 2F/G is designed to launch the unmanned “target spacecraft” and “Space Lab” in the second phase of the Chinese human spaceflight programme Project 921. The launch vehicle is based on the ChangZheng 2F, but with increased payload capacity (~11,200kg) and an enlarged payload fairing. The launcher will not be fitted with an emergency escaping system since it will only be used for unmanned missions. The inertial guidance, flight control and onboard electronic systems of the launch vehicle will be completely redesigned to provide better orbit positioning accuracy and improved fault redundancy.
The first flight of the ChangZheng 2F/G, for launching the TianGong 1 “Target Spacecraft”, is scheduled to take place in October 2010.
ChangZheng 2F/H
The ChangZheng 2F/H is the second-generation launcher for China’s ShenZhou manned spacecraft. It will be the first member of the ChangZheng 2 family to have completely departed from the original two-stage ChangZheng 2C core stage that burns UDMH/N2O4. The first flight of the launcher is expected to take place in 2010~2012.
The ChangZheng 2F/H will use a 3.35m-diameter core module, with four 2.25m-diameter strap-on boosters, all burning liquid oxygen and kerosene (LOX/Kerosene) propellant. The 3.35m diameter core stage consists of two 120t thrust YF-100 engines. The 2.25m diameter strap-on booster consists of a single 120t thrust YF-100 engine.
The ChangZheng 2F/H will be available in two variants: The manned variant is used to launch future ShenZhou spacecraft, with a launch weight of 582 tonnes and a LEO payload capacity of 12,500kg. The unmanned variant is used to launch cargo spacecraft and space station modules, with a launch weight of 579 tonnes and a LEO payload capacity of 13,000kg.
Last update: 18 February 2009 |
