ChangZheng 2F (Long March 2F) Space Launch Vehicle

Last updated: 14 May 2007

The ChangZheng 2F (CZ-2F, or Long March 2F) is the dedicated launch vehicle for China’s manned space programme (Project 921). The launch vehicle is based on the design of the CZ-2E, with improved system redundancy for higher reliability and safety standards. The CZ-2F also has a strengthened upper stage to carry the large ShenZhou spacecraft fairing and launch escape tower. The CZ-2F launch vehicle has so far carried out six flight missions since November 1999, all from Jiuquan Satellite Launch Centre (JSLC), with a success rate of 100%.

The Chinese leadership gave go-ahead to the Project 921 manned space programme in 1992. The whole project comprised seven major development programmes: astronaut system (Project 921-1), application system (Project 921-2), ShenZhou manned spacecraft (Project 921-3), space launch vehicle (Project 921-4), launch site (Project 921-5), control, telemetry, and communication systems (Project 921-6), and landing site (Project 921-7). China Academy of Launch Vehicle Technology (CALT, also known as 1st Space Academy) was responsible for the development of the Project 921-4 to provide a launch vehicle for the manned space programme, with Wang De-Chen appointed as the Chief Designer.

Based on the CZ-2E, the CZ-2F was China’s newest, largest and most sophisticated space launch vehicle, consisting a two-stage liquid-propellant core vehicle with four strap-on stages and an escape system fitted with five solid-propellant rocket motors. For increased safety and reliability, the CZ-2F is also fitted with an advanced fault monitoring and diagnosis system to help the astronauts escape in time of emergency. The CZ-2F is the first Chinese-made space launch vehicle to be vertically assembled and then mated with the ShenZhou spacecraft in the assembly tower. After comprehensive examinations and tests, the launch vehicle and the spacecraft are then transited to the launch pad, also in the vertical position.

The CZ-2F development began in March 1993 . The programme definition was completed in September 1993 and the programme design was completed in September 1994. The launch vehicle design was tested and examined between 1996 and 1997. The first launch site test was carried out in June 1998, and the escape tower was first tested in October 1998. On 20 November 1999, the first operational CZ-2F (codenamed: Y-1) sent the first unmanned ShenZhou spacecraft into the orbit successfully. Between January 2001 and December 2002, three more unmanned ShenZhou missions were carried out using the CZ-2F launch vehicles (Y-2, Y-3, and Y-4). Two manned flight missions, ShenZhoou-5 and -6, were carried out in 2003 and 2005, using the CZ-2F Y-5 and Y-6 launch vehicles respectively.

The booster of CZ-2F consists of a 2-stage core vehicle with four strap-on stages, all employing UDMH/N2O4 (nitrogen tetroxide). 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. Compared to the CZ-2E, the design of the rocket motors on the CZ-2F has been optimised with Russian assistance.

The escape tower is fitted with five solid-propellant rocket motors developed by Academy of Rocket Motor Technology (4th Space Academy). The system would fire to pull the ShenZhou capsule and orbital module away from the launch vehicle in the event of a major launch vehicle malfunction, and then land in the safety zone using a parachute. The system is ready for operation from 15 minutes before launch to the point of escape tower jettison at T + 120 seconds (39,000m altitude). When the fault monitoring management system on CZ-2F launch vehicle senses an emergency situation, it automatically activates the launch escape system. If necessary, the escape system could also be activated remotely by the ground control, or manually by the astronauts from within the spacecraft capsule.

Typical Flight Sequence

• T + 0 sec: Launch vehicle lifts off
• T + 10.000 sec: Launch vehicle pitches over
• T + 120.000 sec: Escape tower jettison
• T + 140.646 sec: Strap-on boosters jettison
• T + 159.876 sec: First-stage is separated from the launch vehicle
• T + 200.870 sec: Spacecraft fairing jettison
• T + 461.206 sec: Second-stage main engine shuts down
• T + 580.206 sec: Second-stage swivelling venire motor shuts down
• T + 583.260 sec: ShenZhou spacecraft is separated from the launch vehicle

Specifications

First launch: 19 November 1999
Last launch: 12 October 2005
Service status: In service
Overall length: 58.34m
Core vehicle diameter: 3.35m
Strap-on stage diameter: 2.25m
Fairing diameter: 3.80m
Launch weight: 480 tonnes
Lift-off thrust: 5,920kN
Payload: 8,000kg (LEO mission)

Launch Records

Gallery

See Also

• Chinese Manned Space Programme
• ShenZhou spacecraft