Engineering:Long March 1D

Long March 1D

Function	Orbital launch vehicle
Manufacturer	CALT
Country of origin	China
Size
Height	28.22 m (92.6 ft)
Diameter	2.25 m (7.4 ft)
Mass	81,650 kg (180,010 lb)
Stages	3
Capacity
Payload to LEO	930 kg (2,050 lb)
Associated rockets
Family	Long March 1
Comparable	Mu 1-3-4
Launch history
Status	Retired
Launch sites	Taiyuan LC-1
Total launches	3
Successes	2
Failures	1
First flight	1 June 1995
Last flight	3 January 2002
Notable payloads	reentry vehicle tests
First stage
Length	18.20 m (59.7 ft)
Diameter	2.25 m (7.4 ft)
Empty mass	4,100 kg (9,000 lb)
Gross mass	65,000 kg (143,000 lb)
Propellant mass	61,100 kg (134,700 lb)
Engines	1 YF-2B (4 x YF-1B)
Thrust	SL: 1,101.2 kN (247,600 lbf) Vac: 1,214.4 kN (273,000 lbf)
Specific impulse	SL: 242.5 seconds (2.378 km/s) Vac: 267.4 seconds (2.622 km/s)
Burn time	131.5 seconds
Fuel	UDMH/N2O4
Second stage
Length	6.04 m (19.8 ft)
Diameter	2.25 m (7.4 ft)
Empty mass	1,620 kg (3,570 lb)
Gross mass	14,000 kg (31,000 lb)
Propellant mass	12,380 kg (27,290 lb)
Engines	2 YF-40
Thrust	98.1 kN (22,100 lbf)
Specific impulse	295.2 seconds (2.895 km/s)
Burn time	365 seconds
Fuel	UDMH/N2O4
Third stage
Length	1.7 m (5.6 ft)
Diameter	2.05 m (6.7 ft)
Empty mass	665 kg (1,466 lb)
Gross mass	1,315 kg (2,899 lb)
Propellant mass	Main: 650 kg (1,430 lb) RCS: 147 kg (324 lb)
Engines	Main: FG-36 SRM RCS: DaFY2-1 monopropellant thrusters
Thrust	44 kN (9,900 lbf)
Specific impulse	289 seconds (2.83 km/s)
Burn time	43 seconds
Fuel	Main: HTPB RCS: hydrazine

The Long March 1D was a member of China's Long March rocket family. During the 1990s CALT developed an improved version of the DF-4 to test the reentry vehicle warheads of the DF-31. They took advantage of this development and offered it as the Long March 1D for commercial application. The modifications included:

• An DF-4 improved first stage, which used the new version of the YF-2B, and switched propellants to UDMH/N₂O₄ for improved performance.
• The replacement of the DF-4 second stage motor YF-3A. The proposed replacement was the Long March 4 third stage engine, the YF-40.
• A new inline inter-stage would replace the existing tapered connector between the second and third stages, which allowed for an additional 70cm diameter to be added to the third stage skirt. This would allow for the addition of RCS to the third stage.
• A new third stage with a new motor, the FG-36 and an optional RCS.
• A new computer inertial guidance system which enabled the third stage to be 3-axis stabilised for added precision.

The new design did not have a good reception and was only used for reentry vehicle tests. It flew three suborbital missions from Taiyuan LC-1 with two successes and a failure on the final mission. The first launch was on June 1, 1995 and the second one was in November 1997. The final and failed launch was on January 3, 2002.

References

• Data from Aerospace China magazine

External links

• China Academy of Launch Vehicle Technology