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 family.  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.   CZ-5 will be augmented by CZ-6 and CZ-7, smaller rockets based on CZ-5 strap-on boosters.  (These variants were originially identified as part of the CZ-5 family and leter renamed.)  The new EELV-class rocket family 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 is 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].  The smaller modules were serve as strap on boosters for CZ-5 and also as core stages for smaller rockets.  CZ-7 would use the 3.35 meter module as a first stage core while CZ-6 would use the 2.25 meter module.        

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 second 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, or a new kerosene fueled stage might be developed.  A new 3.35 meter kerosene upper stage, powered by four new 15 tonne thrust YF-115 engines, was also contemplated.

Development initially focused on the 5 meter core configurations due to the effort required, but CZ-7, the 3.35 meter diameter vehicle, was also pushed forward to become the first of the new rockets planned to fly.   CZ-7 could fly as a two stage rocket, or with two or four 2.25 meter strap on boosters, allowing it to lift from 3 to 10 tonnes to low earth orbit (LEO).  A hydrogen fueled third stage could be added to the most powerful variants for high energy missions, providing up to a 6 tonne geosynchronous transfer orbit (GTO) capability. CZ-7 would, as a result, be able to supplant most of the existing Chinese launch vehicles.   It might also find a role in the manned Shenzhou program.   

CZ-5's 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” (or "CZ-5B" or "CZ-5F" with an upper stage) 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, might 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. 

Planners hint that full implementation of the CZ-5, 6, and 7 family would occur over a very long period of time.  There are no current plans to replace the CZ-2F human launch vehicle, for example.  Plans for the smallest CZ-6 rocket were still uncertain as of early 2013, for example.

Both CZ-5 and CZ-7 will be launched from a new site near Wenchang on Hainan Island off China's southern coastline.     

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.

[2]  "Five Follows Seven, Details of China's New Launcher Family Emerge", Bradley Perrett, Aviation Week & Space Technology, March 12, 2012.

 Last Update:  March 7, 2013