Long March 7

Long March 7^[1][2]

Function	Medium to heavy orbital launch vehicle
Manufacturer	CALT
Country of origin	China
Size
Height	53.10 m (174.2 ft)
Diameter	3.35 m (11.0 ft)
Mass	594,000 kg (1,310,000 lb)
Stages	2
Capacity
Payload to LEO (200km x 400km x 42°)	13,500 kg (29,800 lb)
Payload to SSO 700km	5,500 kg (12,100 lb)
Associated rockets
Family	Long March
Comparable	Delta IV, Atlas V, Falcon 9, H-IIA, Angara
Launch history
Status	In development
Launch sites	Wenchang, Jiuquan, Xichang, Taiyuan
Boosters - K2 booster
No boosters	4
Diameter	2.25 m (7.4 ft)
Engines	1 YF-100
Thrust	SL: 1,200 kN (270,000 lbf) Vac: 1,340 kN (300,000 lbf)
Total thrust	SL: 4,800 kN (1,100,000 lbf) Vac: 5,360 kN (1,200,000 lbf)
Specific impulse	SL: 300 seconds (2.9 km/s) Vac: 335 seconds (3.29 km/s)
Fuel	RP-1/LOX
First Stage - K3 core module
Diameter	3.35 m (11.0 ft)
Engines	2 YF-100
Thrust	SL: 2,400 kN (540,000 lbf) Vac: 2,680 kN (600,000 lbf)
Specific impulse	SL: 300 seconds (2.9 km/s) Vac: 335 seconds (3.29 km/s)
Fuel	RP-1/LOX
Second Stage
Diameter	3.35 m (11.0 ft)
Engines	4 YF-115
Thrust	706 kN (159,000 lbf)
Specific impulse	342 seconds (3.35 km/s)
Fuel	RP-1/LOX

The Long March 7 (Chinese: 长征七号运载火箭), or Chang Zheng 7 as in pinyin, abbreviated LM-7 for export or CZ-7 within China, is a Chinese liquid-fuelled carrier rocket, which is being developed by the China Aerospace Science and Technology Corporation. Its maiden flight is scheduled for 2016. ^[3]

As one of the new generation rocket family of Long March 5, Long March 6 and Long March 7, it is to be a medium-heavy launch vehicle and fits the gap between the heavy Long March 5 family and the small-mid Long March 6 family.

The structure will be based on the reliable man-rated Long March 2F rocket. Thus it will inherit the 3.35m-diameter core stage and 2.25m-diameter liquid rocket boosters. However, it will use LOX/kerosene fuel instead of the expensive and dangerous N2O4/UDMH fuels used previously in the Long March 2 rocket family. The new engine is borrowed from the engines developed for Long March 5, similar to Long March 6. The target is to build a more cost-effective and less environmentally damaging rocket family to replace today's Long March 2 and potentially Long March 3 serial to satisfy both domestic and international launch market needs.^[4] It will be capable of placing 5,500 kilograms (12,100 lb) of payload into a sun-synchronous orbit.^[1]

With payloads in the range of 10-20 tons cited, it is likely to use two YF-100 first-stage engines at the 1st core stage, and one YF-100 engine for each of its 4 liquid rocket boosters.^[5][6]

Bradley Perrett from Aviation Week writes that the description of Long March 7 corresponds with the mid-sized launcher that the China Academy of Launch Vehicle Technology detailed in 2007. The configuration displayed then had the two K3 core modules, four K2 boosters and a special 3-meter-dia. module, H3, that would presumably be an optional third stage for missions beyond low Earth orbit. But the range of payloads quoted for Long March 7, 10-20 tons, shows that it would be built with a variety of booster combinations. A single YF-100 would presumably provide second-stage propulsion.^[5]

References

Long March rockets LM 1 family Long March 1 1D LM 2 family Feng Bao 1 Long March 2A 2C 2D 2E 2E(A) 2F LM 3 family Long March 3 3A 3B 3B/E 3B(A) 3C LM 4 family Long March 4A 4B 4C LM 5 family Long March 5 LM 6 family Long March 6 LM 7 family Long March 7 LM 8 family Long March 8 LM 9 family Long March 9 LM 11 family Long March 11 List of Long March launches China Academy of Launch Vehicle Technology