Vehicle Configurations

Vehicle Components

Since 1970, China’s orbital launches have been performed by Chang Zheng (CZ, or “Long March”) rockets derived from Dong Feng (DF, or “East Wind”) ballistic missiles.   The current CZ-2 to CZ-4 series derived from the two-stage DF-5 intercontinental range ballistic missile.  This series, which first flew in 1973, can haul 2.8 to 9.5 metric tons (tonnes) to low earth orbit (LEO) and 2.6 to 5.1 tonnes to geosynchronous transfer orbit (GTO).  The CZ-2F variant has been used to launch crewed Shenzhou spacecraft.  

Now China’s Academy of Launch Vehicle Technology (CALT) is working toward development of a more powerful launch vehicle.  CZ-5, China’s first pure space launch vehicle design, is expected to be able to haul up to 25 tonnes to LEO or up to 14 tonnes to GTO.   The new EELV-class rocket, which will not fly until 2014 at the earliest, will almost certainly support China’s future manned spaceflight and lunar exploration plans.

CZ-5 will be powered by a new series of liquid engines, including a 120 tonne thrust LOX/Kerosene engine identified as YF-100 and a 50 tonne thrust LOX/LH2 engine named YF-77.  The new engines will do away with the toxic hypergolic UDMH/N2O4 propellants used by the DF-5 based Long March rockets. 

Engine development began in 2000-2001, with testing directed by the China National Space Administration (CNSA) commencing in 2005.  Versions of both engines had been successfully tested by mid-2007.

A complete family of CZ-5 options was initially envisioned, based on a modular approach.  Three module types, with diameters of 2.25 meters, 3.35 meters, and 5.0 meters, were described in some detail during the 2001-2003 period [1].  More recent reports suggest that the core stage diameter may have increased beyond 5 meters.   

Original plans called for the 2.25 meter module to be powered by one 120 tonne thrust kerosene/liquid oxygen (LOX) engine.  Two such engines would boost the 3.35 meter module.  The 5 meter diameter core stage would use two 50 tonne thrust liquid hydrogen (LH2)/LOX engines.  Any of the modules could be used as first stage units on small and medium launch vehicles.  The two smaller modules could also serve as strap-on boosters for the 3.35 and 5 meter core stages, in combinations of two or four. 

Three upper stages, one in each of the three module diameters, were also planned.  The 5 meter upper stage would be powered by two LH2/LOX engines of 8 tonnes thrust each, similar to the YF-75 engines that currently power the CZ-3B upper stage.  The existing CZ-4A second stage might be used as the 2.25 meter diameter upper stage.  A new 3.35 meter kerosene upper stage, powered by four new 15 tonne thrust engines, was also contemplated.

Development would initially focus on the 5 meter core configurations because existing Long March rockets already handle the payload range covered by the smaller CZ-5 designs.  The 5 meter diameter, 31 meter-long core would weigh 175 tonnes at liftoff, including 158 tonnes of propellant.  The core will be augmented by four strap-on boosters, with either two of each diameter (2.25 and 3.35 meter) or with all four of the same diameter.  CZ-5 will fly as a 1.5 stage launcher for LEO missions, and as a 2.5 stage vehicle for GTO and deep-space missions.    

The most powerful CZ-5 version, identified as “CZ-5-504” and equipped with four 3.35 meter modules strapped onto a 5 meter core stage, would liftoff on more than 1,080 tonnes of thrust produced by a total of ten engines, suggesting a possible gross liftoff weight exceeding 800 tonnes.  This CZ-5 version, if built as originally planned, would be the world’s most capable launch vehicle in the post-shuttle era, able to boost more payload mass to orbit than any other launch vehicle.  Russia’s new Angara 5 would not match it in any category.  NASA’s Ares I would weigh more, and both Ares I and Ariane 5 ECA would produce more liftoff thrust, but neither would out-haul China’s new heavy lifter.  

After the heavy lift versions are developed, work could begin on small and medium launchers based on the 2.25 and 3.35 meter modules.  These would replace existing Long March vehicles, but planners hint that this process would occur over a very long period of time.  There are no current plans to replace the CZ-2F human launch vehicle, for example.   As a result, plans given for the small and medium launchers are unlikely to proceed exactly as originally described.

CZ-5 will be launched from a new site near Wenchang on Hainan Island off China's southern coastline.  It also seems likely that some CZ-5 versions could fly from some of China's existing launch centers.  

Vehicle Configurations

Vehicle Components

References

 [1]  The New Generation Launch Vehicles of Long March Family, Tangming Cheng, Xiojun Wang, Dong Li, Beijing Institute of Astronautical Systems Engineering, 54^th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law, October 2003, Bremen, Germany.

 Last Update:  March 2, 2008